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        검색결과 2,489

        941.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There are many pollutants emitted into the air. Some of these pollutants have a malodor. Unlike other pollutants, people are able to detect and feel discomfort when this type of pollutant becomes high peak concentration instantaneously. In this sense, the peak concentration has an important meaning in the odor management and modeling. In previous odor modeling, the peak concentration was calculated by correcting the one-hour average concentration using the correlation equation. This study was carried out to find appropriate method to predict the peak concentration using meteorological input data of high time resolution in the odor modeling. It show that the peak concentration could be directly calculated from the dispersion modeling without using the correction equation when fine time scales such as 1 min or less time intervals are used as the meteorological input.
        4,300원
        942.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A possible heuristic to solve metropolitan area vehicle routing problems with variable vehicle speeds is suggested in this research. Delivery hours are classified into 4 different time zones to make variable vehicle speeds no change within the same time zone to make TDVRP simple to solve. The suggested heuristic consists of 2 stages such as initial solution development step and initial solution improvement step. A computer program using C++ is constructed to evaluate the suggested heuristic. Randomly generated vehicle routing problems are used for the experiments. This heuristic could be helpful to logistics companies by increasing delivery efficiencies since the 4 zone classification is taken from the observed traffic information offered by a local government.
        4,000원
        943.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 숲에서의 체류시간에 따른 생리적 반응을 분석하여 건강증진에 미치는 효과를 규명하기 위하여 진행되었다. 연구는 전주시 건지산 일원의 편백나무 숲에서 평균 연령 53.33세의 여성 18명을 대상으로 숲 체류 5시간 동안의반응을 측정하였다. 생리적 반응으로 뇌파, 심박변이, 혈압, 맥박 등을 측정한 결과는 다음과 같다.숲에서 체류하는 동안 알파파 발생 빈도가 증가하여 생리적 안정이 이루어졌으며 숲에서 4시간 체류할 때 중추신경계의안정을 통해 스트레스 완화효과의 빈도가 높게 나타났다. 자율신경계 측면에서 이완 및 스트레스 완화를 설명하는부교감신경이 활성화되고 혈압 및 맥박의 감소 효과가 나타난 피험자 집단이 숲 체류 후 증가하였으며 최소 2시간부터4시간까지 효과가 나타난 피험자의 빈도가 지속적으로 높게 나타났다. 전반적으로 생리적 반응분석에 의하면, 숲 체류에따른 스트레스 완화효과에 있어서 숲에서 2-4시간 머무를 때 가장 많은 이용자가 스트레스 완화효과를 얻을 수 있을것으로 판단된다.
        4,000원
        944.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, 5-story structures were designed in accordance with KBC2009 for inelastic time history analysis of RC IMRF. Bending moment-curvature relationship for beam and column was identified with fiber model and bending moment-rotation relationship for beam-column joint was calculated with simple and unified joint shear behavior model and moment equilibrium relationship for the joint. The hysteretic behavior was simulated with three-parameter model suggested in IDARC program. The analytical results showed that the inelastic shear behavior of the joint could be neglected in the structural design for seismic design category C but the structure of category D did not satisfy the criteria of FEMA 356 for collapse prevention performance level.
        4,000원
        945.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The accuracy of travel time information is a key measure of effectiveness and reliability of advanced traveler information systems. This study aims at investigating drivers' perception on the acceptable level of information accuracy and their corresponding valuations. METHODS : A questionnaire survey was executed for collecting driver perception data to capture the expectation level of travel time information provided and their willingness to pay for the information. A Tobit model was adopted for exploring the relationship among the acceptable level, driver socioeconomic characteristics and travel attributes. Since drivers' willingness to pay for accurate travel time information can be different according to their travel lengths, a piecewise linear regression model was developed to capture the sensitivity of values of travel time information to travel length. RESULTS : The analysis results suggest that trip purpose and travel time are two dominant factors to determine drivers' acceptable level of travel time information. For business and short trips, drivers want more accurate information than for non-business and long trips. Drivers' willingness to pay for travel time information also varies depending on their incomes, trip purposes and travel lengths. The results also show that drivers' valuation of travel time information provided is sensitive to their travel length. For longer trips, drivers are less sensitive to travel time information and then put less value on the information provided. CONCLUSIONS : Censored nonlinear regression models are developed to estimate drivers' acceptable accuracy for travel time information and their valuation using questionnaire survey data. The findings on drivers perception to the required accuracy of travel time information and their corresponding willingness to pay can be used in the design and deployment of advanced traveler information system to improve its effectiveness and usefulness through high compliance.
        4,000원
        946.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Two-lane highways have one lane in each direction, and lane changing and passing maneuvers take place in the opposing lane depending on the availability of passing sight distance. 2001 Korea Highway Capacity Manual (KHCM) is classified into two classes of two-lane highways (Type I, II), and average travel speed and time-delayed rate are used as measures of effectiveness (MOEs). However, since existing two-lane highways have both uninterrupted and interrupted traffic flow-system elements, a variety of free-flow speeds exhibits in two-lane highways. In addition, it is necessary to check if the linear-relationship between volumes and time-delayed rate is appropriate. Then, this study is to reestablish the relationship between average travel speed, time-delayed rate, and flow. METHODS : TWOPAS model was selected to conduct this study, and the free-flow speeds of passenger cars and the percentage of following vehicles observed in two-lane highways were applied to the model as the input. The revised relationships were developed from the computer simulation. RESULTS : In the revised average travel speed vs. flow relationship, the free-flow speed of 90km/h and 70km/h were added. It shows that the relationship between time delayed-rate and flow appeared to be appropriate with the log-function form and that there was no difference in time-delayed rate between the free flow speeds. In addition to revise the relationships, the speed prediction model and the time-delayed rate prediction model were also developed. CONCLUSIONS : The revised relationships between average travel speed, time-delayed rate, and flow would be useful in estimating the Level of Service(LOS) of a two-lane highway.
        4,000원
        947.
        2012.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An acoustic method for discriminating plankton from fish, in Lake Dom Helvecio of Brazil, is developed. The flow of data from this method is comprised of time varied threshold (TVT), dilation filter, bitmap and mask functions. The TVT can, of itself, precisely explain how to select an appropriate value. The final results of the echogram, which only shows plankton by masking fish signals, is used to examine the acoustic density of plankton by depth and time. The results indicate that the acoustic density of the plankton is at a depth of between 5m to 15m, its density is especially high at 10m to 15m. The results of the acoustic density of plankton by time indicate that May 7 is higher in density than May 8. Future study plans include the use of net samples, environmental datasets to identify the abundance and ecology described by the Chaoborus spp. from other species.
        4,000원
        948.
        2012.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Enhancement of light trapping in solar cells is becoming increasingly urgent for the development of next generation thin film solar cells. One of the possible candidates for increasing light trapping in thin film solar cells that has emerged recently is the use of scattering from metallic nanostructures. In this study, we have investigated the effects of the geometric parameters of Ag nanorings on the light scattering efficiency by using three dimensional Finite Different Time Domain (FDTD) calculations. We have found that the forward scattering of incident radiation from Ag nanorings strongly depends on the geometric parameters of the nanostructures such as diameter, height, etc. The forward scattering to substrate direction is increased as the outer diameter and height of the nanorings decrease. In particular, for nanorings larger than 200 nm, the inner diameter of Ag nanorings should be optimized to enhance the forward scattering efficiency. Light absorption and scattering efficiency calculations for the various nanoring arrays revealed that the periodicity of nanorings arrays also plays an important role in the absorption and the scattering efficiency enhancement. Light scattering efficiency calculations for nanoring arrays also revealed that enhancement of scattering efficiency could be utilized to enhance the light absorption through the forward scattering mechanism.
        4,000원
        949.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the effect of a load cell response time at the weighing type filling system is investigated for high-speed filling. The changes in the characteristics of the physical structure of the load cell is measured and analyzed by using Single point type load cell and Bending beam type load cell. The result has improved the load cell strain and the response time by the analysis of the stress distribution and strain
        4,000원
        952.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: Suggestion of asphalt binder constitutive model based on time-temperature superposition principle and overstress concept in order to describe behavior of asphalt binders. METHODS: A series of temperature sweep tests and multiple stress creep and recovery(MSCR) tests are performed to verify the applicability of time-temperature superposition principle(t-Ts) and to develop viscoelastoplastic constitutive equation based on overstress concept. For the tests, temperature sweep tests at various high temperature and various frequency and MSCR test at 58℃, 64℃ 70℃, 76℃, and 82℃ are performed. From the temperature sweep tests, dynamic shear modulus mastercurve and time-temperature shift function are built and the shift function and MSCR at 58℃ are utilized to determine model coefficients of VBO model. RESULTS: It is observed that the time-temperature shift function built at low strain level of 0.1% is applicable not only to 1.0% strain level temperature sweep test but also maximum 500,00% strain level of MSCR test. As well, the modified VBO model shows perfect prediction on MSCR measured strain at the other temperatures. CONCLUSIONS: The Time-temperature superposition principle stands hold from very low strain level to very high strain level and that the modified VBO model can be applicable for various range of strain and temperature region to predict elastic, viscoelastic, and viscoplastic strain of asphalt binders.
        4,000원
        953.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the past four years, outbreaks of acute respiratory diseases associated with canine influenza H3N2 viruses in dogs and cats have been reported in South Korea and China. For prevention of disease from spread of the disease and for administration of timely medical treatments, including countermeasures for quarantine, use of a rapid and highly sensitive detection method are important to detection of the causative viruses. This study was conducted in order to develop a real time RT-PCR for the H3N2 subtype. It was based on primers targeting the highly homologous sequences of matrix, hemagglutinin, and neuraminidase genes. The detection limit of real time RT-PCR was 10 copies/ul with matrix and hemagglutinin genes, and 1 copy with neuraminidase genes, respectively. This real time RT-PCR was as sensitive as virus isolation in 52 clinical samples. The detection system developed in this study might provide more rapid and highly sensitive results than commercial rapid kits based on immunochromatographic assay.
        4,000원
        954.
        2012.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This paper focuses on the after synthesis of CdTe quantum dots(QDs) in aqueous solution. CdTe nanoparticles were prepared in aqueous solution using mercaptocarboxylic acid or thioglycolic acid(TGA) as stabilizing agents. QDs emit light smaller than the nano size. The contents of the mercaptocarboxylic acid, and a kind of raw material, were revealed for a period of time. We succeeded in synthesizing a very high quality QDs solution; we discussed how to make QDs better and to keep them stabilized. TGA is known as one of the best stabilizing agents. Many papers have mentioned that TGA is a good stabilizing agent. We dramatically confirmed the state of QDs after the experiments. The QDs solution can be influenced by several factors. Different content of TGA can influence the stability of the CdTe solution. Most papers deal with the synthesis of CdTe, so we decided to discuss the after synthesis process for the stability of the CdTe solution.
        4,000원
        955.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        서양종 꿀벌 독의 채집시기와 지역에 따른 봉독의 성분 변화 및 약리효과에 미치는 영향을 검토하였다. 채집시기는 5월부터 9월까지, 채집지역은 전국 35개 지역으로부터 채취한 봉독을 대상으로 2010년과 2011년 2년에 걸쳐 동일 지역에서 동일한 방법으로 봉독을 채취하였다. 채취한 봉독은 액체크로마토그래피를 통해 멜리틴과 아파민 그리고 포스포리파아제 A2의 성분 함량을 분석하였다. 그 결과 채집시기와 지역에 따른 성분에 유의한 차이는 확인되지 않았다(One way-ANOVA, Duncan's test (=0.05)). 봉독의 성분은 채집시기와 지역에 관계없이 멜리틴 , 아파민 그리고 포스포리파아제 A2는 을 차지하였다. 이상의 결과로부터 봉독은 채취시기에 따른 주요 성분은 차이를 갖고 있지 않았으며, 이는 꿀벌의 먹이, 사육온도 등 외부 환경이 봉독 분비에 영향을 주지 않는 것으로 사료되었다.
        4,000원
        956.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate and evaluate microbial contamination levels of leafy greens (perilla leaf and lettuce) and its distributing conditions at different seasons (Feb, May, Aug, and Nov of the year 2011) in order to provide insight into any potential health hazards associated with consumption of these commodities. Leafy greens were collected from a farm located in Geumsan, Chungnam and wholesale markets (WM) and traditional markets (TM) located in Suwon. At the same time, temperature and relative humidity fluctuations experienced by the leafy greens during distribution from the farm to the distribution center were measured by a data logger. The contamination levels of perilla leaf and lettuce were determined by analyzing total plate count. Coliform groups, Bacillus cereus, Escherichia coli, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and Staphylococcus aureus were determined. The contamination levels of total aerobic bacteria, coliform groups and B. cereus in both vegetables sampled during May and August found to be higher than those sampled during February and November. E. coli O157:H7, Salmonella spp., L. monocytogenes were not detected in the vegetables analyzed in this study. There were no significant trends between samples at WM and TM in the contamination levels. Relative humidity of vegetables distributed from the farm to the distribution center showed over 90% during distribution regardless of measured seasons. In the case of background microflora on leafy greens, the density was significantly increased at 20, 30 and 37oC during storage of 24h. E. coli O157:H7 and B. cereus inoculated on the leaves also showed similar increases in the storage tests. The microbial contamination levels determined in this study may be used as the fundamental data for microbial risk assessment.
        4,000원
        957.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 오크라의 노지 재배 시 적정 파종시기를 구명하기 위해 수행되었다. 오크라의 파종시기에 따른 발아율은 4월 15일에 종자를 파종한 구는 4.4%, 4월 30일 처리 구는 66.7%, 5월 15일 처리 구는 88.9%, 그리고 5월 30일 처리 구는 100%였다. 발아율이 가장 높은 처리 구는 5월 30일이었다. 오크라의 생육이 좋은 처리 구는 4월 30일 처리 구였다. 오크라의 생장에서 4월30일 처리 구는 초장이 476cm, 5월 15일 처리 구는 317cm 그리고 5월 30일 처리 구는 271cm였다. 10a당 오크라 수량은 4월 30일 처리 구가 507kg, 5월 15일 처리 구가 836kg, 5월 30일 처리구는 606kg이었다. 10a당 오크라 수량이 가장 많은 처리는 5월 15일 파종구로 836kg이었다. 결과적으로 오크라 노지파종에 적합한 파종일은 제주지역에서 5월 15일이었다.
        3,000원
        958.
        2012.09 구독 인증기관 무료, 개인회원 유료
        This study was conducted to determine the relationship between elapsed time after semen preservation on the changes of bacteria and semen quality. Semen was diluted with BTS(Beltsville Thawing Solution) extender without antibiotic for 7 days and sperm parameter and fertility were measured. Sperm motility was measured by CASA and total bacteria number was counted after 22~24 hr incubation from counting agar plate in which sperm dilute to 10 ~106 in 0.9% saline solution and inoculate to agar. Acrosomal integrity was measured by Chlortetracycline (CTC) staining. CTC patterns were uniform fluorescence over the whole head (pattern F), characteristic of incapacitated acrosome- intact spermatozoa; fluorescence-free band in the post-acrosomal region (pattern B), characteristic of capacitated acrosome-intact spermatozoa; and almost no fluorescence over the whole head except for a thin band in the equatorial segment (pattern AR), characteristic of acrosome reacted spermatozoa. Total number of bacteria was significantly increased (p<0.0001) 3 days after preservation. Sperm motility, viability, and morphological abnormality on elapsed time after preservation were lower from 5 (77.24±6.47, p<0.001) and 7 days (77.24±6.47, p<0.001) after preservation compared to 1 (15.71±7.18) and 3 days(18.39±7.22) after preservation, respectively. Sperm viability was significantly lower (53.25± 35.03, p<0.0001) at 7 days after preservation. Morphological abnormality of sperm was lower (p<0.001) at 1 (15.71±7.18) and 3 (18.39±7.22) days compared to 5 (21.84±7.91) and 7 (22.59±9.93) days after preservation. Acrosomal integrity and capacitation rate (pattern F) were significantly lower (p<0.001) from 5 days after preservation. Based on the data we obtained from this study suggested that semen preserved more than 5 days without antibiotic would not recommend use for artificial insemination.
        3,000원
        959.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 지역사회에 거주하는 정신분열증 환자에게 시간관리 어플리케이션의 적용이 삶의 질에 미치는 영향을 분석하여 작업치료 중재의 임상적 효과를 검증하고자 한다. 연구방법 : 연구 참여자는 만 42세 여성 정신분열증 환자로 2011년 8월 1일부터 9월 23일까지 중재가 이루어졌다. 중재 과정은 처음 1주는 초기평가와 함께 생활시간조사를 분석하였으며, 활동 중에서 의미가 있는 활동과 의미가 없는 활 동으로 분류하였다. 의미가 없는 활동 대신에 생활시간에 본인이 수행하기를 원하는 활동으로 재배치하였다. 그 이후 1주는 어플리케이션 사용법에 대하여 교육하였으며, 중재는 3주간 이루어졌다. 중재가 끝나고 바로 재평가를 실시하 였으며, 추가로 2주 후에는 추적 연구가 이루어졌다. 결과 : S-QOL 점수는 초기 평가에서 45.36점이었으나 중재 후 재평가에서 66.34점으로 향상되었고, 추적 연구에서 60.98점으로 분석되어 중재 후 보다는 감소하였지만 중재 전보다는 증가하였다. 결론 : 시간관리 어플리케이션을 적용한 결과 대상자의 작업 균형이 향상되어 삶의 질이 높아졌다. 따라서 지역사회에 거 주하는 정신분열증 환자들에게 작업치료 중재방법으로 시간관리 어플리케이션이 고려되어야 할 것이다.
        4,600원
        960.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is not easy to establish the correct standard time and standard manhour in a process of small quantity batch production system, especially in a case of irregular quantity of production. Therefore, how to establish rational standard time about manufactu
        4,000원