검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 638

        141.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sewer condition assessment involves the determination of defective points and status of aged sewers by a CCTV inspection according to the standard manual. Therefore, it is important to establish a reliable and effective standard manual for identifying the sewer defect. In this study, analytic reviews of the CCTV inspection manuals of the UK, New Zealand, Canada and South Korea were performed in order to compare the defect codes and the protocols of condition assessment. Through this, we also established the standardized method for defect code and revised the calculation method of assigning the condition grade. Analyses of the types and frequencies of sewer defects that obtained by CCTV inspection of 7000 case results, showed that the joint defect and lateral defect were the most frequent defects that occurred in Korea. Some defect codes are found to be modified because those did not occur at all. This study includes a proposed new sewer defect codes based on sewer characteristics.
        4,300원
        142.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 시스템 식별기술과 칼만필터링을 기반으로 계측된 가속도응답을 이용하여 구조물에 작용하는 모달하중을 역으로 추정하는 기법을 제시하는데 있다. 하중추정 과정에서 가속도응답은 모드응답으로 분해되며 각 모드응답에 대한 모달하중을 역으로 추정한다. 역해석과정에서 발생하는 ill-posed문제를 피하기 위하여 가상진동기에 의해 구조물의 고유진동수와 감쇠비를 보다 정밀하게 구하기 위한 시스템 식별법을 사용하였다. 본 연구에서 제안된 기법의 적용성을 위하여 40층의 철골구조물에 태풍이 작용 했을 때 계측된 가속도를 사용하였다. 적용결과에 의하면 본 연구에서 제안된 하중추정법에 의하여 모달하중 추정이 가능함을 알 수 있었다.
        4,000원
        143.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Theories of advanced composite structures are too difficult for such field engineers and some simple methods are necessary. In this paper, Simple method of vibration analysis is presented. This method presented in this paper is studied self-weight and other loads. The result of the 2~3 times iteration is good enough for field engineering purposes. In the case of cantilevered composite materials beams with different cross section, increase of mass near the support does not significantly affect the vibration characteristics. As a calculations of the simple method of vibration analysis for cantilevered composite materials beams with different cross section, it is noted that the result of the second cycle at the point of free end (actually 5L/6 span) is only 2.2% away from the ‘exact’ solution.
        4,000원
        145.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        One of the important advantages of Thermosonics is that it can be applied to complex structures such as a turbine blade as a convenient and quick screening test method. For a reliable thermosonic test, the vibrational characteristics of the system comprising the tested structure and the clamp at ultrasonic frequency range should be identified. Therefore, this study presented the analysis results of frequency response functions and mode shapes of the turbine blade and clamp system and investigate the possibility of the reliable excitation system for the thermosonic test.
        4,000원
        146.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 인공수정 횟수가 모돈의 번식성적에 미치는 영향을 알아보기 위하여 수행되었다. 총 48두 의 F1 모돈(Yorkshire×Landrace)을 공시하였으며, 완전임의화배치법(CRD)에 의하여 4개의 처리구에 배치되었다. 처리구는 인공수정 횟수(1회, 2회, 3회, 4회)이며, 발정확인 후 12시간 뒤부터 인공수정을 진행하였다. 모돈의 발정확인은 9시와 21시에 웅돈을 접촉시켜서 확인하였으며, 재귀발정일은 5-6일 인 모돈들을 대상으로 구배치 하였다. 모돈의 승가허용 확인 후 12시간 간격에 따라 9시와 21시에 처 리구에 따른 인공수정을 실시하였다. 인공수정 횟수가 모돈의 임신율, 수태율에는 유의적인 영향을 미 치지 않으며, 분만율에서는 3회 인공수정한 처리구가 다른 처리구들에 비해 낮은 수치를 보였다. 총산 자수, 생시자돈수, 복당체중과 같은 분만성적에서도 인공수정 횟수에 따른 통계적 차이는 나타나지 않 았다. 인공수정 횟수의 1회 감소는 7,000원의 정액비용을 절감할 수 있다. 따라서 발정확인 후 인공수 정을 1회하여도 다른 처리구들과 비교해 동일한 번식성적을 가지며, 1회 인공수정을 통한 정액비용의 감소는 농가의 생산비를 절감할 수 있을 것으로 사료된다.
        4,000원
        147.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of our study was to determine the effect of Maitland orthopedic manual therapy, Silver Spike Point, dietary fiber and gymnastic exercise on the improvement of constipation. Forty patients with constipation participated in the study (Maitland Orthopedic Manual Therapy Group(n=10), Silver Spike Point Therapy Group(n=10), Dietary Fiber Group(n=10) and Gymnastics Exercise Group(n=10)). The assessment scale and weekly bowel frequency were measured before and after the experiment. Assessment scale was significantly increased in Silver Spike Point Therapy, Maitland orthopedic therapy, gymnastic exercise compare to dietary fiber. Weekly bowel frequency was significantly increased in gymnastic exercise compared to dietary fiber. The results of this study suggest that Silver Spike Point Therapy, Maitland orthopedic therapy, gymnastic exercise improve the symptom in patients with constipation.
        4,000원
        148.
        2016.10 구독 인증기관 무료, 개인회원 유료
        Low water activity foods usually do not support growth of pathogens. However, in recent years, a number of outbreaks associated with low water activity foods occurred, making people have a new understanding of microorganisms about low water activity foods and resulting in the safety of these foods becoming a major concern. Traditional thermal sterilization methods are difficult to be applied in low water activity foods because of its poor heat transfer and strong heat resistance of microorganisms. Radio frequency (RF) is considered as one of the most potential technologies in food industry and has an excellent prospect on content of the advantages of rapid and uniform heating. The Principle of RF-Sterilization is similar to Microwave, but RF has lower frequency and wider wavelength, therefore RF penetration depth is more suitable for Sterilization. For the pre-packaged food, there is few report on the effect of RF on the food and packaging materials. This presentation aims to discuss the influence of RF through comparing to Microwave.
        4,600원
        149.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We introduce a depth scaling strategy to improve the accuracy of frequency-domain elastic full waveform inversion (FWI) using the new pseudo-Hessian matrix for seismic data without low-frequency components. The depth scaling strategy is based on the fact that the damping factor in the Levenberg-Marquardt method controls the energy concentration in the gradient. In other words, a large damping factor makes the Levenberg-Marquardt method similar to the steepest-descent method, by which shallow structures are mainly recovered. With a small damping factor, the Levenberg-Marquardt method becomes similar to the Gauss-Newton methods by which we can resolve deep structures as well as shallow structures. In our depth scaling strategy, a large damping factor is used in the early stage and then decreases automatically with the trend of error as the iteration goes on. With the depth scaling strategy, we can gradually move the parameter-searching region from shallow to deep parts. This flexible damping factor plays a role in retarding the model parameter update for shallow parts and mainly inverting deeper parts in the later stage of inversion. By doing so, we can improve deep parts in inversion results. The depth scaling strategy is applied to synthetic data without lowfrequency components for a modified version of the SEG/EAGE overthrust model. Numerical examples show that the flexible damping factor yields better results than the constant damping factor when reliable low-frequency components are missing.
        4,000원
        150.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the relationship between frequency of coffee consumption, metabolic biomarkers, and nutrition intake in adult participants in the combined 2007~2009 Korean National Health and Nutrition Examination Survey (KNHANES). Subjects (2,095 males and 3,297 females) were classified according to sex and frequency of coffee consumption (≤1 time/month, ≥2 times/month and ≤6 times/week, 1 time/day, 2 times/day, 3 times/day) using food frequency questionnaires. Nutrition intake was analyzed using 24 h recall data. The 3 times/day coffee consumption group had a significantly higher age, and frequency of smokers and drinkers compared to the ≤1 time/month coffee consumption group in both male and female participants. Males in the 3 times/day coffee consumption group had a significantly lower HDL-cholesterol level, but females had a higher waist circumference compared with the ≤1 time/month coffee consumption group. Males in the 3 times/day coffee consumption group had a significantly lower nutrient density of fiber, vitamin B2, vitamin C, calcium and phosphorus compared with the ≤1 time/month coffee intake group. Females in the 3 times/day coffee consumption group had a significantly higher nutrient density of fat and niacin, but lower nutrient density of carbohydrate, calcium, phosphorus, and iron compared with the ≤1 time/month coffee intake group. In males, the frequency of coffee consumption was not associated with the levels of metabolic biomarkers. In females, the frequency of coffee consumption was positively associated with diastolic blood pressure after adjustments for multiple confounding factors, including age, BMI, smoking status, alcohol consumption, physical activity and energy intake. Coffee consumption was associated with decreased diastolic blood pressure in females. These findings suggest the importance of an awareness of the association between coffee consumption and metabolic risk.
        4,000원
        151.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to assess RF-EMF exposure levels in indoor daycare centers in a Metropolitan city. RF-EMF measurements were collected and surveyed from 50 volunteer daycare centers in the Korea between October 2013 and October 2014. Through our research, it was found that the main exposure source for indoor daycare centers is the frequency bands for TV and Radio broadcasting (FM: 88.1~107.9 MHz), mobile phone (869~894 MHz, 1840~1870 MHz, 1885~2170 MHz), wireless LAN and home electronics, etc., including TRS, Wireless Data Communication. The RF-EMF exposure levels for all daycare centers were far below the recommended standards of EMF Guideline Korea and international reference levels proposed by ICNIRP (International Commission on Non-Ionizing Radiation Protection). However, in terms of long term health effects some uncertainty exists, and thus minimizing exposure may reduce this uncertainty. The data we collected will be useful data for determining RF-EMF management and risk communication at daycare centers.
        4,000원
        152.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was conducted to evaluate the effects of migration frequency on growth performance, blood profile, pork quality and economical analysis in growing-finishing pigs. A total of 56 growing pigs [(Yorkshire×Landrace)×Duroc] with an initial body weight 28.01±4.09 kg were used in this experiment. Pigs were randomly allocated to one of two treatments in a randomized complete block design and 7 replicates with 4 pigs per pen. Experimental treatments were 1) 1 site: growingto- finishing at 1.24 m2/head, 2) 2 site: growing facility for 6 week at 0.81 m2/head followed by move to the finishing facility at 1.24 m2/head. Feeding trial was composed by two growing phase (0-3 week, 4-6 week) and two finishing phase (7-9 week, 10-12 week). As a result, different pig flows influenced on growth performance of growing-finishing pigs and 1 site treatment showed higher average daily gain, average daily feed intake, and G:F ratio on growing phase (0-6 week, p<0.01). The 2 site treatment showed higher serum cortisol level at week 6 (p=0.03). In carcass evaluation, 1 site treatment had shorter days to slaughter 110 kg body weight (p=0.01). Consequently, 1 site system had better performance and economical profits for swine farms.
        4,000원
        153.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyze the dynamic response property of latticed domes according to natural frequency ratio of substructure. Through eigenvalue analysis, it is was confirmed that the half-open angle 30° and 45° dominate vibration mode of the vertical direction and the half-open angle 60° and 90° dominate vibration mode of the horizontal direction. Through the dynamic response analysis, it is was confirmed that the first frequency about total structure largely appears about the vertical and the horizontal direction regardless of half-open angle.
        4,000원
        154.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Composite resins are developed as restorative materials to improve esthetics and mechanical properties. To improve the physical properties of resin material, resin filler have to be added. However, no imaging method is adopted for resin filler distribution. Optical coherence tomography (OCT) is a optical imaging technique to delineate microscopic structures within biological tissue. The OCT application to dental composites resin and its filler is not described yet. So, this new and advanced optical method is needed for clinical application for evaluation of dental composite resin. To analyze the spatial distribution of dental composite resin and to evaluate the resin restoration in cavity, frequency domain optical coherence tomography (FD-OCT) was used for their analysis. Resin restored tooth was prepared. For morphological observation, serially sectioned teeth, conventional X-ray taking and micro computed-tomography (CT) images were compared with OCT images. The experiment has done to evaluate the success of the resin restoration using 3 dimensional structure OCT image. In this research, OCT is evaluated as a new technique to image resin restoration. The evaluation of resin restored tooth was performed by OCT. Inappropriate restoration such as marginal adaptation, large porosities, internal integrity and poor contour could be detected. Resin filler also could be checked by OCT. The distribution, number, regularity and size of resin filler can be differentiated from several commercial products. Considering the characteristics of the OCT, it can be used to evaluate the defects of resin restoration, resin filler distribution, and internal integrity between resin material and tooth structure. The OCT can be considered to be a new and advanced method for the evaluation of resin restorations.
        4,000원
        155.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purposes of this study were to: 1) identify sub-factors of fashion shopping orientation (FSO) in adults aged 20 through 39, and analyze the differences among those FSO factors according to classified groups, which were based on gender and purchase frequency in a mobile shopping mall, and 2) to investigate the effects of FSO factors on mobile purchase intention according to the same classified groups. The questionnaire was conducted from November 10, 2015 to November 20, 2015 and its 432 respondents were classified into four groups, which were male/heavy purchaser, male/light purchaser, female/heavy purchaser, and female/light purchaser. The results of this study were as follows: First, fashion shopping orientation consisted of five sub-factors, which included “conspicuous brand pursuit”, “economic pursuit”, “pleasure/trend pursuit”, “impulse shopping”, and “convenience pursuit”. Second, There were significant differences in three factors of FSO between male purchasers and female purchasers. Male purchasers showed higher tendency than female purchasers in “conspicuous brand pursuit”, while female purchasers showed higher tendency than male purchasers in “economic pursuit” and “convenience pursuit”. All the factors of FSO showed significant differences among the classified groups. Third, “economic pursuit”, “pleasure/trend pursuit” and “convenience pursuit” affected mobile purchase intention in the case of male purchasers while “economic pursuit” and “conspicuous brand pursuit” had a influence on mobile purchase intention in the case of female purchasers. Fourth, the factors of FSO affected mobile purchase intention partly in each group. In conclusion. “economic pursuit” was proven to be the main influential factor to induce consumers to have a mobile purchase intention.
        4,600원
        156.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 지역별, 학교별, 계절별 고등학교 급식 식단의 미생물학적 안전성 관련 주요 영향 인자를 도출하고자 식단 데이터를 수집하고 요인을 분석하여 향후 안전관리 방향을 설정하기 위해 실시하였다. 급식식단 중 PHF(Potentially Hazardous Food) 해당여부, 사용빈도가 높은 엽경채류, 식단 조리방법에 관하여 빈도 분석과 다중대응분석(Multiple correspondence analysis, MCA)을 실시하였다. 중부지역과 남부지역의 각각 3개 고 교, 총 6개 고등학교의 3, 6, 9, 12월 제공된 총 1,945개 식단의 빈도분석 결과, PHF에 해당하는 식단은 데친 나 물류, 샐러드, 해조류, 닭튀김 등이 사용빈도가 높았다. 조리방법은 가열 여부에 따라 단순 가열, 단순 비가열, 혼합 여부에 따라 가열한 식재료와 가열한 식재료의 혼합, 비가열한 식재료와 비가열한 식재료의 혼합, 가열한 식재료와 비가열한 식재료의 혼합으로 구분하였는데, PHF 제품 내 단순 비가열과 가열한 식재료와 비가열한 식재료의 혼합과 같은 메뉴 유형도 33.1% 수준으로 나타났다. 사용빈도가 높은 엽경채류는 시금치, 부추, 상추, 양배추, 깻잎, 양상추, 치커리, 파, 브로콜리 순서로 나타났다. 전체 식단 중 사용빈도가 높은 엽경채류 14종 370개의 데 이터에 대한 MCA 결과 PHF에 해당하는 엽경채류에는 양상추, 청경채가, Non-PHF에 해당하는 엽경채류에는 브로콜리, 양배추, 치커리, 깻잎이 주로 사용되었다. 지역별로는 중부지역에서는 마늘쫑과 시금치가, 남부지역에는 미나리 사용빈도가 상대적으로 높았다. 향후 단체급식에서 농산물의 미생물학적 안전성을 높일수 있도록 생산단계에서 오염원 차단(GAP 인증), 저감 및 세척 공정 개발, 식재료별 조리방법에 따른 메뉴 데이터 베이스화, 미생물학적 안전성이 확보되는 조리방법을 활용한 식단 개발 및 검증이 필요하다.
        4,000원
        159.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated peer-to-peer interaction during collaborative, computer-mediated reading tasks. Fourteen university EFL students in Korea worked in pairs to complete three gapfill tasks. The transcript data from these tasks were analyzed to determine: (1) how often collaboration occurs during collaborative reading tasks, (2) the ways in which peers help each other, and (3) how successful peers are in resolving the problems they collaboratively pursue. The results showed that each of these aspects of interaction varied among sets of pairs. On average, however, the participants collaborated to jointly solve 75% of the problems they encountered. They also used a range of helping behaviors during collaboration. While the participants correctly resolved nearly half of the problems they attempted, half were incorrectly answered or unresolved. Based on these findings, pedagogical implications are offered, in addition to suggestions for future research into collaborative reading tasks.
        6,400원
        160.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the nutrition knowledge, perception, and intake frequency of milk and milk products among middle school students as well as provide the basic data needed for increasing milk and milk product consumption. To achieve the purpose of this study, a survey with 385 students of four middle schools located in Chuncheon was conducted. The level of nutrition knowledge of milk and milk products in females was slightly higher than that in males (p<0.01). Flavored milk and ice cream were preferred the most in each category, and ‘taste’ influenced the selection of milk and milk products the most. The intake frequency of whole milk was the highest, and that of flavored milk was lowest among various milks. Ice cream showed the highest intake frequency while cheese showed the lowest among milk products. Male students showed higher intake frequency of milk and milk products. Groups having high level of nutrition knowledge showed the highest intake of whole milk, whereas groups having a low level of nutrition knowledge preferred processed milk, low fat or non-fat milk, and cheese the lowest.
        4,000원