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        검색결과 189

        21.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study was conducted to analyze the effects arising from extending the duration of nighttime road construction on improving road quality and durability. METHODS : Most previous studies estimating the social cost of various construction conditions did not consider road pavement cooling time as a factor in improving road pavement quality. This study investigated the feasibility of achieving higher road quality and durability by extending the duration of nighttime road construction time extension. For this investigation, the effects of such an extension on traffic conditions were analyzed based on micro-simulation studies and scenario-based cost-benefit analyses, using factors including traffic volume, delay, construction cost, and road pavement cooling time. RESULTS : The results of the traffic simulation studies and cost-benefit analyses indicate that the current road construction method that emphasizes completing nighttime road construction by 6 a.m. reduces pavement life while causing relatively little traffic delay. If the night construction time is instead extended to 2 p.m., road pavement lifetime is increased, reducing road re-construction cost. These savings are greater than the cost of congestion arising from extending the duration of nighttime construction. CONCLUSIONS : The current nighttime construction durations need to be extended in order to efficiently manage roads and reduce road management costs.
        4,000원
        22.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        강풍으로 인한 구조물의 파괴는 한계상태 이상의 풍하중으로 인한 파괴와 한계상태 보다 레벨은 낮지만 반복적인 풍하중에 의한 피로파괴로 나눌 수 있다. 한계상태설계 파괴에 대한 연구는 많이 이루어져 있으나, 강풍에 의한 피로파괴에 관한 연구는 드물다. 본 논문은 강풍에 의한 피로파괴 해석 시 사용할 수 있는 풍속의 계속시간에 관한 모델을 기상관측소로부터 획득한 자료를 사용하여 확률통계방법에 의하여 제시한 것이다. 강풍의 발생성인은 한국의 기상 특성에 따라 태풍, 전선풍, 계절풍으로 나누었고, 년최대풍 속자료에 대한 통계적인 처리는 극치Ⅰ형 누적분포함수를 사용하였다. 1회 강풍이 불었을 때 어떤 레벨에서 풍속의 계속시간은 풍속의 확률밀도함수와 최대풍속값에 의해 일반화된 누적신간의 곱으로 각 강풍의 발생성인에 따라 주어진다.
        4,000원
        23.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to determine the effects of supplementary lighting intensity and duration on selected Cassulaceae species grown in a hydroponic system. Five subfamilies in Crassulaceae with corresponding species were chosen as experimental units namely Sedeveria ‘Letizia ’, Sedum ‘Sun Red’, Crassula rupestris, Echeveria ‘Momotaro’, and Graptoveria opalina. Light duration (3 and 6 hours) and intensity (4,000 lux or 60 μmol • m−2 • s−1 and 8,000 lux or 120 μmol • m−2 • s−1), and their combinations served as factors which were replicated twice. Results revealed that the use of supplementary lighting using LED fixtures had influenced selected species under Crassulaceae. The use of three hours supplementary lighting under low light intensity had statistically similar results with those of the control S. letizia, C. rupestris and G. opalina in particular parameters. Meanwhile, succulents under six-hour with high intensity condition grew well, compared to species S. letizia, C. rupestris and E. ‘Momotaro,’ demonstrating that the data was significantly different. Interestingly, there were no statistical significant differences between species C. rupestris and the control regardless of change of variables (duration and intensity) in all parameters.
        4,000원
        24.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 일조시간과 강수량 자료를 이용하여 다중회귀 방법을 통해 일사량을 추정하였다. 연구에 사용된 자료 들은 강릉지역에 위치한 강원지방기상청(105 관측소, 1980-2007)과 신강원지방기상청(104 관측소, 2009-2014) 그리고 강릉원주대학교(GWNU 관측소, 2013-2014)이며, 105 관측소 자료를 통해 산출된 회귀식을 104 관측소와 GWNU 관측 소에 적용하여 비교분석하였다. 먼저, 일조시간만을 이용하였을 때 104 관측소는 기존 연구들과 유사한 상관계수(0.96) 와 표준오차(1.16 MJ m−2 )가 나타났고, GWNU 관측소에서는 높은 상관계수(0.99)와 낮은 표준오차(0.57 MJ m−2 )로 분석 되었다. 그리고 일조시간과 강수량 자료를 104 관측소에 적용하였을 때 상관계수 0.96과 표준오차 0.99 MJ m−2로 일조 시간만을 적용했을 때보다 표준오차가 감소되었다. 일조시간만을 이용한 방법보다 강수량이 추가된 방법은 관측 일사량 과 편차의 극값이 −26.6%(2010년 3월)에서 −31.0%(2011년 2월)로 증가되었다. 이는 강수량이 5월과 7-9월에 집중되어 나타나 이외의 월에서 추정식의 계수가 음으로 계산되었기 때문으로 분석된다. 따라서 한반도와 같이 강수량이 여름철 에 집중되는 지역에서는 월평균 강수량을 일사량 추정에 이용할 때 주의를 기울여야 할 것이다.
        4,200원
        25.
        2015.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We study an association between the duration of solar activity and characteristics of the latitude distribution of sunspots by means of center-of-latitude (COL) of sunspots observed during the period from 1878 to 2008 spanning solar cycles 12 to 23. We first calculate COL by taking the area- weighted mean latitude of sunspots for each calendar month to determine the latitudinal distribution of COL of sunspots appearing in the long and short cycles separately. The data set for the long solar cycles consists of the solar cycles 12, 13, 14, 20, and 23. The short solar cycles include the solar cycles 15, 16, 17, 18, 19, 21, and 22. We then fit a double Gaussian function to compare properties of the latitudinal distribution resulting from the two data sets. Our main findings are as follows: (1) The main component of the double Gaussian function does not show any significant change in the central position and in the full-width-at-half-maximum (FWHM), except in the amplitude. They are all centered at  11◦ with FWHM of  5◦. (2) The secondary component of the double Gaussian function at higher latitudes seems to differ in that even though their width remains fixed at  4◦, their central position peaks at  22.1◦ for the short cycles and at  20.7◦ for the long cycles with quite small errors. (3) No significant correlation could be established between the duration of an individual cycle and the parameters of the double Gaussian. Finally, we conclude by briefly discussing the implications of these findings on the issue of the cycle 4 concerning a lost cycle.
        4,000원
        26.
        2015.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 열수침지 및 과열증기 처리한 당근을 IQF 방 법으로 급속 냉동 한 다음 -12, -18, -24 o C에서 24주 동안 저장한 후 해동하여 이화학적 및 영양학적 특성과 미생물 학적 변화를 분석하여 열처리 및 냉동 저장의 최적 공정 과정을 확립하고자 하였다. 대체적으로 과열증기 처리한 당근보다 열수침지 처리한 당근의 ΔE이 큰 값을 나타내었 고, 열처리 후 생당근에 비해 전단력이 감소하였으나 급속 냉동 후 저장 기간에 따른 유의적인 차이를 나타내지 않았 다(p>0.05). 열처리 후 생당근에 비해 총균수가 감소되었지 만 냉동 저장시 일정한 경향을 보였고, 열수침지 처리한 당근의 비타민 C 손실양이 과열증기 처리한 당근보다 더 많았다. 열수침지 처리 후 감소한 유리당의 함량은 저장 기간에 따른 변화는 없던 반면, 과열증기 처리 후 급속 냉 동 한 당근의 유리당 함량은 증가하였다. 당근의 유기산의 함량은 열수침지 처리 후 감소하였으나 과열 침지 처리 후 oxalic acid와 malic acid 함량은 증가하는 경향을 보였다. 이를 통해 열처리 후 영양 성분의 손실이 더 적은 과열증 기법의 공정 과정이 열수침지법보다 더 적절한 것으로 보 인다. 또한 -12 o C에서 저장한 당근의 비타민 C가 6개월 후 모두 파괴되었던 것을 통해 비타민 C의 파괴를 최소화하 기 위해서는 이보다 더 낮은 온도에서 냉동 저장해야 할 것이라 사료된다.
        4,000원
        27.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국내 육성 벼 29품종의 저장기간과 발아온도에 따른 발아율와 발아속도 및 종자활력변화는 다음과 같았다. 1. 국내 육성 벼 29 품종의 발아율은 저장기간 5개월에서15개월까지 차이가 없거나 적었으며 저장기간 30개월에는 발아율이 저하되는 품종이 많아졌다. 2. 발아속도계수는 저장기간 5개월보다 10개월에 약간 증가하였다가 이후 30개월까지 완만하게 감소하였다. 3. 발아온도가 발아율에 미치는 영향은 저장 15개월까지는 처리온도 간 유의한 차이가 없었으나 저장 30개월에는 저온(15oC)에서 크게 낮아졌다. 발아속도계수는 발아율과 달리 발아온도 간 차이가 뚜렷하여 15, 20, 25, 30oC에서 모두 일정한 정도의 차이를 두고 비슷한 경향을 나타내었다. 4. 저장기간 30개월까지 발아율이 98%이상이며 발아속도가 높은 품종은 칠보, 일품, 다산2호, 하이아미, 추청, 일미, 새추청, 백진주이었다. 발아율이 89%이하이며 GCV가 0.25이하인 품종은 영안, 홍진주, 목양, 고아미4호, 고품, 큰눈이었다.
        4,000원
        28.
        2014.07 구독 인증기관 무료, 개인회원 유료
        How to manage these marketing and R&D functions is very important in the new product development (NPD) process. Which function should have more power to make more decisions? Previous study seldom touched this question. Further, according to strategic contingent theory, perceived uncertainty is very important determinant for power structure in the NPD process (Hickson, Hinings, Schneck, & Pennings, 1971). However, Pfeffer and Salancik (1978) argued that there is indeterminacy between environment and power structure. Thus, is external environmental uncertainty related to power structure in the NPD process? Resource dependence theory gives us a hint to solve this puzzle, that is, the concept of institutionalization (Pfeffer, 1981; Pfeffer and Salancik, 1978). The current study tends to adopt NPD duration reflected institutionalization (Pfeffer, 1981) to examine the moderating effect of NPD duration on the relationship between environmental uncertainty and marketing-R&D power structure in the NPD process. In general, power is defined as that the relation among social actors in which a specific social actor can potentially influence the decision to achieve his or her desire outcomes (Dahl, 1957; Emerson, 1962; Pfeffer, 1981; Salancik & Pfeffer, 1977). This definition also suggested that power is the structure in human aggregates like complex organization (Pfeffer, 1981). Thus, the power structure in the NPD process is defined as the proportion of decision making by marketing and R&D functions in the NPD process. When a NPD team faces the high market uncertainty, marketing function can gather more resources because of its special ability. A new product team has the limited resources, so another important function like R&D will have fewer resources than marketing function. Thus, our first hypothesis is that the higher market uncertainty, the more power marketing function has. R&D members have background knowledge to overcome the difficult of processing technological language and decide the main resolutions. The team will tend to allot more resources to deal with the problems of technological change as such the R&D members can buy the license of new technologies to apply it on their new products and to create the disruptive innovation like smartphones or tablets successfully. Therefore, the second hypothesis is that the higher technology uncertainty, the more power R&D function has. According to resource dependence theory, however, the relationship between environmental uncertainty and power structure does not always exist (Pfeffer, 1981; Pfeffer & Salancik, 1978). Pfeffer and Salancik (1978) indicated that the perceived environmental uncertainty of a subunit is weakly related to subunit’s power structure when an organization is highly institutionalized. When one subunit has more power than others, it tends to maintain the current power structure. So, the subunit makes rules or norm to formalize its power legally. This process is so called institutionalization (Pfeffer, 1981; Pfeffer & Salancik, 1978). In general, as time goes by, organizations will form their own social norms, and some of these norms will become the principles or rules in organizations (Pfeffer, 1981). As a result, when NPD time is long, marketing and R&D functions form norms or official rules. Then, the relationship between their perceived environmental uncertainty and power structure in the NPD process is weaker than the relation in the shorter duration of NPD. Therefore, our hypothesis is that the relationship between environmental uncertainty and power structure in the long-run project time is weaker than the relationship in the short-run project time. The current study used questionnaire survey and purposive sampling method to collect data. In order to eliminate the bias of common method variance (CMV), this study conducted multiple sources including project managers, the member charging marketing, and the member charging R&D to administrate questionnaires differently. In order to avoid selection bias, this study, moreover, asked the informants select the most recent new products developed and launched for minimum of twelve months. We sent three types of questionnaires to project managers, the member charging marketing, and the member charging R&D respectively. The current study sent questionnaires to 112 firms, and 69 firms are returned. The response rate is 61.61%. At new product level, there are 207 new product projects, and 100 firms are returned. The response rate is 48.31%. We also do tests of bias due to nonresponse which were conducted by using a comparison of early to late respondents’ all variable means (Armstrong & Overton, 1977). No evidence of a bias was found. Our variables are included market and technology uncertainty, and power structure which the left side is totally decided by marketing and the right side is totally decided by R&D. Moreover, NPD time is from star-up projects to launch it. In order to rule out other effects, we controlled industrial category, firm age, the number of marketing and R&D members involved in the NPD process, environmental hostility, and NPD process formalization. Every overall fit index in our measurement model is shown that χ(55)^2=71.5259,p-vaule=.066,χ^2/df=1.30<2, goodness of fit index=.90,adjusted goodness of fit index=.84,comparative fit index=.97,normed fit index=.87,non-normed fit index=.95, and root mean square error of approximation=.06. In general, all fit indexes in our measurement model are acceptable, and the average variance extracted (AVE), composite reliability (CR), and Cronbach’s α of all constructs are acceptable. Their ranges are .45-.70, .70-.93, and .75-.93 respectively. The overall model showed that the higher market uncertainty, the more power marketing has (β=-.279, t-value=-3.11, p-value<.050) but technology uncertainty is not significantly related to power structure. We used the mean of the NPD time as the cutting point to split short-run and long-run project time, and the mean is about one year and half in our sample. The result showed that in the short-run group the higher market and technology uncertainty, the more power marketing and R&D function have (β=-.355, t-value=-2.53, p-value<.050; β=.296, t-value=2.23, p-value<.050) . However, in the long-run group the relationship between environmental uncertainty and power structure is statistically insignificant. Additionally, in the long-run group the more NPD process formalization, the more power R&D function has (β=.277, t-value=2.33, p-value<.050). Back to the original puzzle, that is, does external environmental uncertainty determine power structure in the new product development process? The empirical evidence is shown that it is dependent on how long an organization develops new products to the market. Because the dominant subunit involved in the NPD process tends to maintain it power, it institutionalizes rules or norms to have legitimacy in the organization, and this argument is consistent with resource dependence theory (Pfeffer & Salancik, 1978). We also found that in short-run perceived environmental uncertainty are positively related to power structure in the NPD process. Consistent with strategic contingent theory’s proposition, the one subunit enable to reduce or respond external environment pressure, and it can have more power in the organization (Hickson, et al., 1971; Hinings, et al., 1974). We additionally found that in long-run group process formalization is positively related to R&D power. R&D function plays a main role in the NPD process as especially in the manufacturing industry; therefore, R&D function has much motive to maintain its power (Workamn, 1993). So R&D function can use formal rule to maintain its power when R&D function formalize the NPD process. As a consequence, formalizing the NPD process helps R&D function to gain more power in the long run. The contribution of our study is that we tested the proposition in strategic contingent theory, and the empirical evidences supported our hypotheses. Furthermore, our study also is the first study to test and find the support evidence with the institutionalization proposition in resource dependence theory. We not only explored the relationship between environmental uncertainty and power structure in the NPD process, but also extended strategic contingent theory and resource dependence theory to the NPD research. The further study can follow our definition of power structure to find what strategy marketing and R&D function will used to take back or maintain their power (Eisenhardt & Bourgeois, 1988; Li & Atuahene-Gima, 2001; Pfeffer, 1981).
        3,000원
        29.
        2014.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to determine the duration of maintained calf muscle flexibility gained in young adults with calf muscle tightness, as measured by increases in ankle active and passive dorsiflexion range of motion (DFROM) after three stretching interventions. Twenty subjects (5 men and 15 women) with calf muscle tightness received the following three stretching interventions in one leg (assigned at random): static stretching (SS), eccentric training on stable surface (ETS), and eccentric training on unstable surfaces (ETU). The subjects received all three interventions to the same leg, applied in a random order. Each intervention had a break of at least 24 h in-between, in order to minimize any carryover effect. Each intervention used two types of stretching: with the calf muscle stretched and both knees straight, and with the knee slightly bent in order to maximize the activation of the soleus muscle. All three interventions were performed for 200 seconds. We measured the duration of maintained calf muscle flexibility through active and passive ankle DFROM before intervention, immediately after intervention (time 0), and then 3, 6, 9, 15, and 30 min after intervention. We found a difference in the duration of maintained calf muscle flexibility between the three interventions. In the ETS and ETU interventions, a significant improvement in calf muscle flexibility, both ankle active and passive dorsiflexion ranges of motion (ADFROM and PDFROM), was maintained for 30 min. In the SS intervention, however, ADFROM before 9 min and PDFROM before 6 min were statistically different from the baseline. Our results suggest that ETS and ETU may be more effective than SS for maintaining calfmuscle flexibility in young adults.
        4,000원
        30.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        수출용 오리엔탈나리 ‘시베리아’의 여름철 고랭지 절화품질을 높이기 위하여 4단계의 대형 구근을 이용하여정식 전 싹틔우기 처리로 시험한 결과, 작은 구근일수록 저온 싹틔우기 기간이 짧은 처리가 효과적이었으며,구근 크기가 클수록 기간이 길 때 효과적이었다. 구주18cm에서는 2οC 0일+5οC 7일+12οC 14일, 구주20cm에서는 2οC 7일+5οC 7-14일+12οC 14일, 구주22cm에서는 2οC 14일+5οC 14일+12οC 14일과 2οC21일+5οC 7일+12οC 14일, 구주 24cm에서는 2οC 14-21일+5οC 7일+12οC 14일 처리했을 때 절화장이 크고, 화수장 비율이 25-27%로 양호하였다. 수확소요일은약 10일 더 빨랐고, 꽃 수는 1개 감소하였고, 블라인드는 0%, 절화등급은 2.2~b1.0로 절화 품질이 향상되는효과를 나타냈다.
        4,000원
        31.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to compare the duration of hamstring flexibility improvement after 3 stretching interventions in people with limited hamstring flexibility. Twenty-two subjects (12 men, 10 women) with limited hamstring flexibility of the dominant leg received 3 stretching interventions— modified dynamic stretching (MDS), hold-relax (HR), and static stretching (SS)—in a random order. All the subjects received all 3 interventions at intervals of at least 24 hours to minimize any carry-over effect. Modified dynamic stretching was applied as a closed kinetic chain exercise in the supine position by using the sling suspension system (Redcord Trainer®). The SS and HR interventions were individually performed in the straight leg raising (SLR) position, and all 3 interventions were performed for 3 minutes. Outcome measures included passive knee extension (PKE) measurements. Five post-test measurements were recorded for all subjects at 3, 6, 9, 15, and 30 minutes after the interventions. MDS was associated with a significant increase in knee extension range of motion even at 30 minutes post-treatment. In contrast, the HR and SS stretching methods showed increased hamstring flexibility for only 6 minutes post-treatment. Improvements in the range of motion of knee extension (indicating enhancement in hamstring flexibility) with MDS were maintained longer than those with the HR and SS interventions. Therefore, MDS may be more effective than the other interventions for maintaining hamstring flexibility.
        4,000원
        32.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to investigate the effect of sleep duration on dietary habits and body composition of university students. Sleep duration has recently been added to the list of risk factors for obesity. However, studies on this topic are fairly limited particularly in Korea. We studied the relationship between the duration of sleep and obesity principally based on body mass index and %body fat in university students. For this purpose, a survey was conducted on a total of 312 university students. The subjects enrolled for this study were divided into two groups: (1) those with sleep duration of 〈7 hours (148 students) and (2) those with sleep duration of 〉7 hours (164 students). Based on a self-reporting method, the participants filled up the questionnaires for more than 20 minutes. Based on the overall data obtained, we observed that most students (52.88%) skipped breakfast. This was mainly due to shortage of time (60.58%). We also observed that self-reporting dietary preferences included eating irregular meals (49.04%), overeating (19.55%), imbalanced diet (16.35%), and skipping meals (9.94%). It was found that cookies were the favorite snacks in the majority of the participants (50%). Our data reveal that the body mass index, fat mass, visceral fat, and subcutaneous fat, respectively of the shorter sleep duration group (〈7 h/day) were 23.78 kg/m2, 19.13 kg, 2.23 kg, and 11.15 kg. In contrast, in those of the control group (7 h/day), these values were found to be 21.84 kg/m2, 13.88 kg, 1.56 kg, and 12.11 kg. We also observed that there were significant correlations of sleep duration with body mass index (p〈0.05), fat mass (p〈0.01), visceral fat (p〈0.01), and beck depression score (p〈0.01). Our data suggest that the body mass index in the shorter sleep duration group was higher than that of the control group; however, %fat, visceral fat, and subcutaneous fat in the shorter sleep duration group were found to be higher than those of the control group. The data obtained through our study suggest that short sleep duration is clearly associated with a modest increase in general and abdominal obesity particularly in university students.
        4,000원
        33.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study deals with first traffic violations occurred by novice drivers, which may be associated with traffic accidents. The objective of this study is to identify what kinds of drivers' characteristics influence on duration till the first traffic violation. METHODS : For the study, Survival Analysis and Cox proportional hazard model, that are usually used in the medical field, were employed. Survival Analysis was conducted to investigate whether there exist differences in survival duration by each covariate, whereas Cox proportional hazard model was used to identify significant factors that affect survival duration till novice drivers violate traffic regulations for the first time after getting a driver license. RESULTS : The results of Survival Analysis indicate that female, age (less than 21), low-frequency examinee of written exam, and non-crash involved drivers have longer duration till the first violation compared to male, greater than 21 years old, high-frequency examinee of written exam, and crash involved drivers, respectively. For the Cox proportional hazard model, license class 1 acquisitor was found to increase the survival duration till the first traffic violation was made, while male, age of 21-24, age of 25-34, age of 45-54, and crash involved drivers were more likely to reduce the survival duration. CONCLUSIONS : Absolutely, traffic violation is closely related to traffic accidents and all of the drivers should keep the traffic regulations to enhance highway safety. The results of this study might provide some insights to construct safe road environments by controlling the factors that reduce the traffic violation duration of novice drivers.
        4,500원
        34.
        2013.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, firstly, acceleration-time histories were generated by varying strong motion duration in the frequency domain for application to a seismically isolated nuclear power structure, so as to examine the effects of strong motion duration on the behavior of the structure. Secondly, real recorded earthquakes were modified to match the target response spectrum based on the revised SRP 3.7.1(2007) and the modified time histories were applied to the analysis of a seismically isolated nuclear power structure. The obtained values of acceleration and displacement responses of the structure were, finally, compared with the values obtained in case of applying acceleration-time histories generated in the frequency domain to the structure.
        4,000원
        35.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study focuses on the quality assessment of Black Bengal buck semen preserved at chilled condition. In this in vitro trial, collected semen from Black Bengal bucks was preserved at chilling temperature (4▲5줛) in tris-glucosecitrate yolk medium of 1:5 ratios for four days. Artificial Vagina (AV) method was utilized to collect semen from buck. General evaluation of semen includes the color, mass activity and density were measured by direct visual examination. However, computer-assisted sperm analysis (CASA) and phase contrast microscopy were used to figure out the motility (%), hyper-activated (HYP) motility (%) and number of abnormal spermatozoa (%) initially, and at every 24 h intervals. The result revealed that spermatozoa preserved at chilling temperature showed significantly (P<0.05) lower motility and HYP motility with the progression of preservation. The number of phenotypically abnormal spermatozoa significantly (P<0.05) increased following preservation. Although significant positive correlation (r=0.945; P<0.05) was existed between % motile and % HYP motile spermatozoa however, the % of morphologically abnormal spermatozoa was negatively correlated with % motile (r=긏0.997; P<0.05) and % HYP motile spermatozoa (r=긏0.946; P<0.01). Therefore, we concluded that the quality of chilled semen progressively losses its viability and doesn…t remain useable after certain period of preservation with respect to its motility and morphology.
        4,000원
        36.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effects of Chromium-Methionine (Cr-Met) chelate feeding for different durations on growth and carcass characteristics in the late fattening stage of Holstein steers. Nine Holstein steers were randomly assigned to three dietary treatments (3 head per treatment) including Non Cr-Met chelate feeding (NCM, av. BW of 433.3 kg), Cr-Met chelate feeding for 2 months (2CM, av. BW of 459.6 kg), and Cr-Met chelate feeding for 4 months (4CM, av. BW of 490.0 kg), respectively. The feeding amount of Cr-Met chelate to an animal was limited to 400 ppb/day. Dry matter intake showed no differences among all the treatments (p>0.05). Average daily gain was also higher in the animals fed Cr-Met chelate diets than NCM (p<0.05). Carcass weights were also observed to be higher in Cr-Met chelate feeding treatments, especially in 4CM compared with other treatments (p<0.05). Although no significant differences were observed on back fat thickness and rib eye area(p<0.05), but 4CM showed much higher effects than NCM and 2CM. Marbling score meat color, fat color, texture, and maturity were not affected by treatments (p>0.05). The variations in meat quality were smaller in 4CM compared to other treatments. 4CM showed higher total and net income than other treatments (p<0.05). Therefore, the current study concluded that Cr-Met chelate supplementation for 4 months could increase daily gain, carcass characteristics, and profitability of Holstein steers in the late fattening stage.
        4,000원
        38.
        2013.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to analyze the grip strength by the girth of upper arm and forearm and their muscle activities by duration of grip strength. The subjects were consisted of 20 healthy adults(10 males & 10 females) who had no medical history of neurological and surgical problems with their arms. Girth of upper arm/ forearm and maximum grip strength for 4sec and 30sec were measured. Muscle activity was by wireless electrode EMG system. Co-relation of girth of upper arm/ forearm was significantly high. Upper arm's muscle activity performed for 4sec and 30sec was significantly high. In this study. It suggests that training of upper arm should be performed with the training of grip strength because both of upper arm and forearm affected grip strength.
        4,000원
        39.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to assess the influence of the duration of smartphone usage on cervical and lumbar spine flexion angles and reposition error in the cervical spine. The study included 18 healthy smartphone users (7 males and 11 females). We measured the kinematics of the upper and lower cervical and lumbar spine flexion angles and the reposition error of the upper and lower cervical spine after 3 s and 300 s smartphone use in sitting. A paired t-test was used to compare the effects of the duration of smartphone usage on the kinematics of cervical and lumbar spine flexion angles and reposition error. The flexion angles of the lower cervical and lumbar spine and the reposition error in the upper and lower cervical spine were significantly increased after 300 s smartphone of use (p<.05). However, the flexion angle of the upper cervical spine was not significantly different between the 3 s and 300 s smartphone of use (p>.05). These findings suggest that prolonged use of smartphones can induce changes in cervical and lumbar spine posture and proprioception in the cervical spine.
        4,000원
        40.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        나리 구근의 수확시기와 저온저장 기간에 따라 형태 적 특성 및 내부 구성물질의 변화는 구근 품질에 영 향을 준다. 본 연구는 구근 수확시기와 저온저장 기간 이 오리엔탈 나리 ‘Siberia’와 ‘Sorbonne’ 구근의 nose 크기와 당 함량에 미치는 영향을 구명하였다. 구근은 충남 태안에서 9월부터 11월까지 1주일 간격으로 수확 하여 형태적 특성(구주, 구경, 구고, 구중, nose 높이, nose 폭)과 총 당 및 유리당 함량을 측정하였다. 그 결과, 구중에서 ‘Siberia’는 10월 중순까지 증가한 후 감소하였고, ‘Sorbonne’는 11월 초까지 증가한 후 감 소하였다. Nose 크기는 품종에 관계없이 수확시기가 늦어질수록 증가하였다. 총 당과 sucrose 함량은 11월 초까지 증가하였는데 이는 지속적인 광합성 산물의 이 동 및 축적과 관련이 있는 것으로 보인다. 저온저장 기간과 구근 특성의 관계에 있어서는, 저온저장 기간이 길어질수록 품종에 관계없이 nose가 커졌다. 저온저장 기간 동안 fructose와 glucose는 3월말까지 감소하다가 그 후 증가한 반면, sucrose는 단당류의 증가 시기에 감소하였지만 총 당 함량은 일정 수준을 유지하였다.
        4,000원
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