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        검색결과 6

        1.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2000년 이후 급격한 생활환경의 변화와 근래에 발생한 예측 불가능한 전염병 등의 영향으로 국내․외의 여행과 이동을 자제하고 건강을 위한 야외활동은 기존에 조성되어 온 유명한 둘레길, 숲길 등의 공익적 가치가 더욱 중요하게 부각되고 있다. 본 연구는 CVM을 활용하여 충청도와 경상도를 가로지르는 숲길을 연결하는 가칭 ‘동서트레일’에 대한 환경적 가치를 추정하였다. 연구는 동서트레일을 방문한 탐방객을 대상으로 하였으며, 723부를 분석에 이용하였다. 조사대상지 를 방문한 응답자의 기본적인 이용행태는 주 2-3회 정도 운동하는 건강에 관심이 많은 사람들이며, 거주지에서 멀지 않은 곳의 숲길을 친구나 가족들과 방문하고, 1회 방문 시 약 5만원 이상을 소비하는 경향을 보이고 있다. 둘레길을 방문할 때 숲길코스에 대한 안내판이 부족하다는 것을 느끼고 있으며, 적절한 장소에 쉼터를 설치해 주기를 원하는 것으로 나타났다. 동서트레일의 보존가치를 추정하기 위한 방법은 Hanemann식 이중경계 로짓모형을 이용하였다. 동서트레일 방문자가 1회 방문 시 얻을 수 있는 환경적 가치는 30,087원으로 추정할 수 있었다. 추정된 금액을 동서트레 일 인근 직접이용권에 속한 인구로 환산하면 동서트레일의 연간 환경가치는 약 940억원으로 추정할 수 있다. CVM을 이용한 숲길에 대한 환경의 가치추정에 대한 연구는 현재까지 진행된 적이 없으며, 추정된 연구 결과는 국가 숲길 정책에 대한 타당성을 제시해 줄 수 있을 것이다.
        4,000원
        2.
        2018.11 구독 인증기관·개인회원 무료
        Interferon tau (IFNT), has known as a key signal molecule for a period of pregnancy in ruminants owing to the need on maternal recognition of pregnancy. It is generated in trophectoderm cells of the elongation bovine conceptus at day 13-21 and a peak output is at day 15-17 of pregnancy period. Moreover, other studies indicated that it can be effective in the embryonic development and quality. In previous study, there were 8 bovine IFNT, but only 2 forms of IFNTs, IFNT2 and IFN-tau-c1, were expressed by the conceptuses during the peri-implantation. In this study, we target the one between the two, IFN-tau-c1 and then the effect of IFNT knockout in donor cells to bovine cloned embryonic development by somatic cell nuclear transfer (SCNT) was investigated. In order to proceed this study, the immature oocytes from the ovaries at local slaughterhouse have been matured in vitro for 22 hours. For preparing the donor cell that have a mutation on IFNT gene, somatic cells were transiently transfected with Cas9 protein and single guide RNA targeting IFNT, and various single derived colonies with high proliferation were isolated and confirm the mutation by PCR. Finally, one colony had mono-allelic mutation (4bps deletion) was picked out and applied as the donor cell to SCNT. A donor cell was injected into an oocyte that nucleus was removed. Reconstructed oocytes with the donor cell were fused by electrical shock, activated by chemical stimulation and cultured for 7 days in chemically defined medium. In this study, control (n=199) and IFNT knockout-group (n=219) were compared with four replications. As results, there was no significant difference between control-and IFNT-knockout group not only in cleavage rate, but also blastocyst formation rate (Control: 12.3% ± 9.2, IFNT knockout-group: 20.1 ± 11%). In addition, the number of blastocyst cell was not different between control (91.7 ± 26.2) and IFNT knockout group (83.5 ± 21.3). Some IFNT mutated blastocysts from SCNT were randomly selected for confirmation of the deletion of IFNT and all samples were positive for mutation. In conclusion, these data indicated that the interruption of IFNT did not influence the embryonic development. In future study, we will transfer these mutated embryos toto test the effect of IFNT for pregnancy period. This work was supported by BK21 PLUS Program for Creative Veterinary Science, the National Research Foundation of Korea (2017R1A2B3004972) and the Technology Development Program (S2566872) by MSS.
        3.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The global small and mid-sized display market is changing from thin film transistor-liquid crystal display to organic light emitting diode (OLED). Reflecting these market conditions, the domestic and overseas display panel industry is making great effort to innovate OLED technology and incease productivity. However, current OLED production technology has not been able to satisfy the quality requirement levels by customers, as the market demand for OLED is becoming more and more diversified. In addition, as OLED panel production technology levels to satisfy customers’ requirement become higher, product quality problems are persistently generated in OLED deposition process. These problems not only decrease the production yield but also cause a second problem of deteriorating productivity. Based on these observations, in this study, we suggest TRIZ-based improvement of defects caused by glass pixel position deformation, which is one of quality deterioration problems in small and medium OLED deposition process. Specifically, we derive various factors affecting the glass pixel position shift by using cause and effect diagram and identify radical reasons by using XY-matrix. As a result, it is confirmed that glass heat distortion due to the high temperature of the OLED deposition process is the most influential factor in the glass pixel position shift. In order to solve the identified factors, we analyzed the cause and mechanism of glass thermal deformation. We suggest an efficient method to minimize glass thermal deformation by applying the improvement plan of facilities using contradiction matrix in TRIZ. We show that the suggested method can decrease the glass temperature change by about 23% through an experiment.
        4,000원
        4.
        2016.10 구독 인증기관·개인회원 무료
        The CRISPR/Cas9 system is proved to be a powerful tool for knock-out and knock-in in various species. By introducing genetic materials of two components (Cas9 and small guide (sg) RNA) into cells or pronuclear of the fertilized embryo, gene editing occurs. Some studies reported that efficiency of gene editing would be increased as Cas9 was integrated into cells or animals since Cas9 is indispensable in the CRISPR/Cas9 system. Accordingly, the production of Cas9 expressing cattle may provide the broadly used gene editing platform in cattle. For this study, Cas9 and RFP genes were cloned into PiggyBac (PB) transposon system. PB-Cas9-RFP and transposase were microinjected into 1436 in vitro fertilized embryos and 241 blastocysts were formed. Blastocysts with RFP expression accounting for 14.1% of total formed blastocysts were selected and transferred into 5 recipient cow. After gestation periods, four transgenic cattle were delivered without any veterinary assistance. From a transgenic cattle, ear skin tissue was collected for primary culture. On those primary cells, sgRNAs in DNA form for various genes such as PRNP, RB1 and BLG were transfected as 2ug of sgRNA per 5x105 cells using Nucleo factor system (Neon®, invitrogen, program#16). As expected, every group of each sgRNA delivered was confirmed to be mutated by T7E1assay. Those data demonstrated that for the first time, transgenic cattle with Cas9 expression were born, grown up to date and will be avaluable resource for genome-editing in cattle. This work was supported by BK21PLUS Program for Creative Veterinary Science and Seoul Milk Coop (SNU550-20160004).
        5.
        2020.02 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to examine the differences of use behavior and environmental perception of a park and to analyze the influence of environmental perception factors on park satisfaction among 7 parks in Suseong-gu, Daegu. The data from the 255 questionnaires of young adults (30-59) and old adults (more than 60) who use the park more than once a week were used for the analysis. In terms of park use behavior, young adults used the park for walking and jogging mainly on weekday evenings, while old adults used the park for walking and rest mainly during weekday daytimes. In addition, old adults used the park more times a week than young adults, and spent more time in the park. In the analysis of the environmental perception of the park, similar results were found in both age groups but overall, old adults were more satisfied with the park environment than the young adults. As a result of analyzing the influence of environmental perception factors, it was determined that park satisfaction in young adults has a significant influence on 'use amenity', 'use convenience', 'facility suitability', and 'landscape diversity' in this order. On the other hand, park satisfaction for old adults has an influence on 'use amenity', 'facility suitability', and 'use convenience' in this order. The findings of this study can be used as an effective basic data for future park planning considering age groups.
        6.
        2019.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to analyze the effect of perceived walking environment around neighborhood on satisfaction for old adults in Daegu. The study was conducted using 407 questionnaires were collected through the survey. The walking environment was categorized into accessibility to neighborhood walking facilities and walking environment around path. Regarding perception of walking accessibility, access to ‘public transit stops’ and to ‘medical facilities’ was relatively high. For walking environment, ‘pavement condition’, ‘continuity of sidewalk’, and ‘slope of sidewalk’ were rated relatively high. Multiple regression analysis after factor analysis of walking environment variables showed that religious and convenient facilities, park and leisure facilities, and medical and welfare facilities had a significant effect on satisfaction in walking accessibility. For walking environment the convenience for walking, safety for walking, and amenities for walking had a significant effect on satisfaction. The findings from this study can be used for improving the walking environment for old adults.