• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.587-594
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• 2000

At present embryonic stem (ES) cells with confirmed pluripotential properties are only available in the mouse. Recently, we were able to isolate, culture and genetically transform primordial germ cell (PGC)-derived cells from pig embryos and demonstrate their ability to contribute to chimera development in the pig. In order to determine whether the system we developed could be used to isolate embryonic germ (EG) cells from other mammalian species, we placed isolated PGCs from cattle, goats, rabbits and rats in culture. Briefly, PGCs were isolated from fetuses of cow (day 30-50), goat (day 25), rabbit (day 15-18) and rat (day 11-12), and plated on STO feeder cells in Dulbecco's modified Eagle's medium (DMEM): Ham's F10 medium (1:1) supplemented with 0.01 mM nonessential amino acids, 2 mM L-glutamine, 0.1 mM $\beta$ - mercaptoethnol, soluble recombinant human stem cell factor (SCF; 40ng/ml), human basic fibroblast growth factor (bFGF; 20ng/ml) and human leukemia inhibitory factor (LIF; 20ng/ml). For maintenance of the cells, colonies were passed to fresh feeders every 7-10 days. In all species tested, we were able to obtain and maintain colonies with ES-like morphology. Their developmental potential was tested by alkaline phosphatase (AP) staining and in vitro differentiation assay. For genetic transformation, cells were electroporated with a construct containing the green fluorescent protein (GFP) under the control of the cytomegalovirus (CMV) promoter. GFP-expressing colonies were detected in cattle, rabbits and rats. These results suggest that PGC-derived cells from cattle, goats, rabbits and rats can be isolated, cultured, and genetically transformed, and provide the basis for analyzing their developmental potential and their possible use for the precise genetic modification of these species.

• 한국산림과학회지
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• 제101권4호
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• pp.619-625
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• 2012

본 연구는 국내 분포하는 가침박달 집단의 열매, 종자 및 발아 특성에 대한 변이를 조사하였다. 5개 자연집단의 96개 개체목에서 열매를 채취하여 5가지 열매특성, 7가지 종자특성 및 3가지 발아특성을 분석하였다. 평균발아 일수를 제외한 14가지 특성들에서 집단간 및 집단내 개체간에 유의적인 차이가 인정되었다. 열매와 종자 특성은 대체적으로 전체 분산 가운데 집단이 차지하는 비율이 높은 것으로 나타났다. 변이계수 값을 보면 열매특성은 열매무게 27.0%, 종자특성은 종자길이/두께 28.1%, 발아특성은 발아속도 52.5%로 가장 높은 값을 나타냈다. 가침박달 집단의 평균 발아특성은 발아율 62.9%, 평균발아일수 64.0일, 발아속도 0.40개/일로 나타났다. 상관분석결과 평균발아일수는 종자두께와 발아속도는 모수의 수고 및 위도와 각각 정의 상관관계를 나타냈다. 또한 위도가 높을수록 열매가 무겁게 나타나는 정의 상관관계를 나타냈다. 군집분석결과 집단의 분포에 따른 지리적인 경향은 나타나지 않았다. 주성분분석 결과 제1주성분의 기여도가 전체변이의 63%를 설명하였으며, 고유값(Eigenvalue)이 1 이상인 제3주성분까지의 기여도는 97%로 가침박달 열매, 종자 및 발아특성 분류에 중요한 정보를 주는 요인으로 나타났다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5889-5897
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• 2015

Background: The performance of combined testing visual inspection with acetic acid (VIA) and cervical cytology tests might differ from one setting to another. The average estimate of the testing accuracy across studies is informative, but no meta-analysis has been carried out to assess this combined method. Objective: The objective of this study was to estimate the average sensitivity and specificity of the combined VIA and cervical cytology tests for the detection of cervical precancerous lesions. Materials and Methods: We conducted a systematic review and a meta-analysis, according to the Cochrane Handbook for Systematic Review of Diagnostic Test Accuracy. We considered two cases. In the either-positive result case, a positive result implies positivity in at least one of the tests. A negative result implies negativity in both tests. In the both-positive case, a positive result implies having both tests positive. Eligible studies were identified using Pubmed, Embase, Website of Science, CINHAL and COCRANE databases. True positive, false positive, false negative and true negative values were extracted. Estimates of sensitivity and specificity, positive and negative likelihood (LR) and diagnostic odds ratios (DOR) were pooled using a hierarchical random effect model. Hierarchical summary receiver operating characteristics (HSROC) were generated and heterogeneity was verified through covariates potentially influencing the diagnostic odds ratio. Findings: Nine studies fulfilled inclusion criteria and were included in the analysis. Pooled estimates of the sensitivities of the combined tests in either-positive and both-positive cases were 0.87 (95% CI: 0.83-0.90) and 0.38 (95% CI: 0.29-0.48), respectively. Corresponding specificities were 0.79 (95% CI: 0.63-0.89) and 0.98 (95% CI: 0.96-0.99) respectively. The DORs of the combined tests in either-positive or both-positive result cases were 27.7 (95% CI: 12.5-61.5) and 52 (95% CI: 22.1-122.2), respectively. When including only articles without partial verification bias and also a high-grade cervical intraepithelial neoplasia as a threshold of the disease, DOR of combined test in both-positive result cases remained the highest. However, DORs decreased to 12.1 (95% CI: 6.05-24.1) and 13.8 (95% CI: 7.92-23.9) in studies without partial verification bias for the combined tests in the either-positive and both-positive result cases, respectively. The screener, the place of study and the size of the population significantly influenced the DOR of combined tests in the both-positive result case in restriction analyses that considered only articles with CIN2+ as disease threshold. Conclusions: The combined test in the either-positive result case has a high sensitivity, but a low specificity. These results suggest that the combined test should be considered in developing countries as a primary screening test if facilities exist to confirm, through colposcopy and biopsy, a positive result.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5923-5931
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• 2015

Background: Registry data from four major public hospitals indicate trends over three decades from 1980 to 2010 in treatment and survival from colorectal cancer with distant metastases at diagnosis (TNM stage IV). Materials and Methods: Kaplan-Meier product-limit estimates and Cox proportional hazards models for investigating disease-specific survival and multiple logistic regression analyses for indicating first-round treatment trends. Results: Two-year survivals increased from 10% for 1980-84 to 35% for 2005-10 diagnoses. Corresponding increases in five-year survivals were from 3% to 16%. Time-to-event risk of colorectal cancer death approximately halved (hazards ratio: 0.48 (0.40, 0.59) after adjusting for demographic factors, tumour differentiation, and primary sub-site. Survivals were not found to differ by place of residence, suggesting reasonable equity in service provision. About 74% of cases were treated surgically and this proportion increased over time. Proportions having systemic therapy and/or radiotherapy increased from 12% in 1980-84 to 61% for 2005-10. Radiotherapy was more common for rectal than colonic cases (39% vs 7% in 2005-10). Of the cases diagnosed in 2005-10 when less than 70 years of age, the percentage having radiotherapy and/or systemic therapy was 79% for colorectal, 74% for colon and 86% for rectum (&RS)) cancers. Corresponding proportions having: systemic therapies were 75%, 71% and 81% respectively; radiotherapy were 24%, 10% and 46% respectively; and surgery were 75%, 78% and 71% respectively. Based on survey data on uptake of offered therapies, it is likely that of these younger cases, 85% would have been offered systemic treatment and among rectum (&RS) cases, about 63% would have been offered radiotherapy. Conclusions: Pronounced increases in survivals from metastatic colorectal cancer have occurred, in keeping with improved systemic therapies and surgical interventions. Use of radiotherapy and/or systemic therapy has increased markedly and patterns of change accord with clinical guideline recommendations.

• 경영정보학연구
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• 제11권1호
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• pp.19-47
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• 2009

현재 많은 제품 개발이 기존 제품 또는 서비스에 새로운 형상과 기능을 추가하는 컨버전스를 통해 이루어지고 있다. 그러나 제품 개발에서 컨버전스는 제품사용에 대한 긍/부정적 효과를 동시에 유발하며 나아가 소위 "기술의 패러독스" 문제를 내포하고 있다. 한편으로는 기능성 또는 형상의 추가를 통해 제품의 유용성을 향상시키지만 다른 한편으로는 제품 사용 및 사용을 학습의 복잡성을 증가시켜 사용자의 제품에 대한 만족과 서비스 평가에 부정적 영향을 줄 수 있기 때문이다. 이러한 관점에서 본 연구는 대표적 컨버전스 서비스 사례인 텔레매틱스 서비스를 대상으로 이러한 역설의 문제를 탐색한 실증적 결과를 제시하고 있다. 따라서 본 연구의 모델은 "기능다양성", "사용복잡성", "인지된 유용성", "서비스평가", "서비스적합성"과 같은 변인을 채택하여 기술의 역설의 존재를 검증할 수 있도록 설계되었다. 제안된 연구모델과 이에 따른 가설은 실제 텔레매틱스 서비스 사용자 149명으로부터 자료를 수집하여 PLS를 이용한 경로모형분석을 통해 검증되었다. 연구 결과 첫째, 기능다양성의 증가는 인지된 유용성과는 정의 관계가 있으나 사용복잡성과는 부의 관계에 있음이 확인되었다. 둘째, 사용자의 서비스 평가에 대한 영향은 인지된 유용성이 사용복잡성에 비해 더 큰 영향을 미치는 것으로 확인되었다. 마지막으로 연구 결과 1, 2의 변인 간 인과관계의 강도가 서비스 적합성에 의해 부분 조절되는 현상을 확인하였다. 이러한 연구결과는 컨버전스 서비스와 관련된 사용자의 믿음, 태도를 설명함에 있어서 기술의 역설의 영향을 강조하고 있다.

• 한국정보과학회논문지:시스템및이론
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• 제32권11_12호
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• pp.629-638
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• 2005

시스템 온 칩 설계에서 온 칩 버스는 전체 시스템의 성능을 결정하는 중요한 요소이다. 특히 프로세서, DSP 및 멀티미디어 IP와 같이 보다 높은 버스 대역폭을 요구하는 IP가 사용될 경우 온 칩 버스의 대역폭 문제는 더욱 심각해진다. 이에 따라 최근 ARM 사에서는 고성능 온 칩 버스 구조인 ML-AHB 버스 매트릭스를 제안하였다. ML-AHB 버스 매트릭스는 시스템 내의 다중 마스터와 다중 슬레이브간의 병렬적인 접근 경로를 제공하여 전체 버스 대역폭을 증가시켜주고, 최근 많은 프로세서 요소들을 사용하는 휴대형 기기 및 통신 기기 등에 적합한 고성능 온 칩 버스 구조이다. 하지만 내부 컴포넌트인 입력 스테이지와 무어 타입으로 구현된 중재 방식으로 인해 마스터가 새로운 전송을 수행할 때 또는 슬레이브 레이어를 변경할 때 마다 항상 1 클럭 사이클 지연 현상이 발생된다. 본 논문에서는 이러한 문제점을 해결하기 위해 기존 ML-AHB 버스 매트릭스 구조를 개선하였다. 기존 버스 매트릭스 구조에서 입력 스테이지를 제거하고, 개선된 구조에 적합하도록 중재 방식을 변경하여 1 클럭 사이클 지연 문제를 해결하였다. 개선된 결과 4-beat incrementing 버스트 타입으로 다수의 트랜잭션을 수행할 경우, 기존 ML-AHB 버스 매트릭스에 비해 전체 버스 트랜잭션 종료 시간 및 평균 지연 시간이 각각 약 $20\%,\;24\%$ 정도 짧아졌다. 또한 FPGA의 슬라이스 수는 기존의 ML-AHB 버스 매트릭스보다 약 $22\%$ 정도 감소하였고, 클럭 주기도 약 $29\%$ 정도 짧아졌다.

• 한국물환경학회지
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• 제36권5호
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• pp.385-391
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• 2020

Soil loss is a serious problem frequently caused by local torrential rainfalls due to climate change. In particular, soil loss is occurring in agricultural areas rather than urban areas, and many pollutants are introduced into rivers, causing environmental problems. To reduce soil loss, the Ministry of Environment has designated and managed non-point source management areas. The Jaun-district in Hongcheon-gun, which was designed as a non-point pollution source management area in Gangwon-do, is located in the upper stream of Soyang Lake. Most of the agricultural fields are composed of highland agriculture fields. The highland agricultural fields in the Jaun-district are also composed of large-scale farming areas, and the ditches located near the agricultural fields have been illegally used for farmland. Therefore, the local government in Hongcheon-gun is conducting a project to restore the ditches occupied by agricultural fields. However, an analysis of the amount of soil loss that can be reduced by the restoration of the ditches has not been conducted yet. Thus, the purpose of this study was to analyze the effect of reducing the soil loss from the restoration of the ditches used as agricultural fields in the Jaun-district. The SATEEC L Module was used to analyze the reduction in soil loss by ditch restoration. The SATEEC L Module was constructed to estimate the LS factor using Moore and Burch's method after calculating the slope length using the digital elevation model and the maximum allowable slope length. The LS factor and the USLE formula were used to estimate the amount of soil loss that could be reduced by ditch restoration. The analysis showed that the ditch restoration could reduce about 16.6% of the soil loss in the Jaun-district. The results of this study will contribute to the study of methods to reduce soil loss in non-point pollution management areas.

• 토지주택연구
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• 제11권2호
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• pp.33-46
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• 2020

As the fastest growing office transaction volume in Korea, there's been a need for development of indicators to accurately diagnose the office capital market. The purpose of this paper is experimentally calculate to the office price index for effective benchmark indices in Seoul. The quantitative methodology used a Case-Shiller Repeat Sales Model (1991), based on actual multiple office transaction dataset with over minimum 1,653 ㎡ from Q3 1999 to 4Q 2019 in the case of 1,536 buildings within Seoul Metropolitan. In addition, the collected historical data and spatial statistical analysis tools were treated with the SAS 9.4 and ArcGIS 10.7 programs. The main empirical results of research are briefly summarized as follows; First, Seoul office price index was estimated to be 344.3 point (2001.1Q=100.0P) at the end of 2019, and has more than tripled over the past two decades. it means that the sales price of office per 3.3 ㎡ has consistently risen more than 12% every year since 2000, which is far above the indices for apartment housing index, announced by the MOLIT (2009). Second, between quarterly and annual office price index for the two-step estimation of the MIT Real Estate Research Center (MIT/CRE), T, L, AL variables have statistically significant coefficient (Beta) all of the mode l (p<0.01). Third, it was possible to produce a more stable office price index against the basic index by using the Moore-Penrose's pseoudo inverse technique at low transaction frequency. Fourth, as an lagging indicators, the office price index is closely related to key macroeconomic indicators, such as GDP(+), KOSPI(+), interest rates (5-year KTB, -). This facts indicate that long-term office investment tends to outperform other financial assets owing to high return and low risk pattern. In conclusion, these findings are practically meaningful to presenting an new office price index that increases accuracy and then attempting to preliminary applications for the case of Seoul. Moreover, it can provide sincerely useful benchmark about investing an office and predicting changes of the sales price among market participants (e.g. policy maker, investor, landlord, tenant, user) in the future.

• 한국방재학회 논문집
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• 제9권6호
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• pp.77-87
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• 2009

전염병 발생의 잠재적 위험은 지구촌 사회의 시대를 맞이하여 심각하게 증가하였다. 그러나 여러 국가들의 다양한 정부기관에서 전염병에 대한 지방자치단체의 대응계획은 적절한 수준으로 준비되어 있지 않은 실정이다. 인류는 의료 및 공중보건에서 괄목할만한 성장을 이룩해왔다. 그러나 SARS는 아직도 막대한 인명손실을 야기시킬 수 있는 잠재력을 가진 매우 위험한 전염병으로 남아있다. 2002년 11월부터 2003년 7월까지 SARS는 전세계적으로 8,096건의 사례가 발생하였으며 774명의 사망자와 9.6%의 사망률을 결과하였다(WHO, 2004). 이는 대표적인 보건재난 중 하나이다. 중국이 전세계에서 발생한 총 SARS사례의 약 66%를 점유한 결과 이웃국가인 한국의 관광산업은 심각한 영향을 받게 되었다. 본 연구의 목적은 한국의 입국자 자료의 주요요소를 파악하고, SARS발생기간 동안 한국에 입국한 일본과 대만 관광객의 수요변화가 한국의 관광산업에 미친 경제적 영향을 분석하는 것이다. 본 연구의 결과로서 일본, 미국, 중국, 대만의 4개 국가 입국자들의 계절적, 장기적 추세를 파악할 수 있었으며 한국 관광산업에 대한 SARS의 직 간접적 영향을 분석할 수 있었다.

• The Korean Journal of Physiology
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• 제20권2호
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• pp.257-270
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• 1986

It has been reported that the luteal function may be regulated by the intracellular calcium in luteal cells (Higuchi et al, 1976; Dorflinger et at, 1984; Gore and Behrman, 1984) which is adjusted partially by $Ca^{++}-ATPase$ activities in luteal cell membranes (Verma and Pennistion, 1981). However, the physicochemical and kinetic properties of $Ca^{++}-ATPase$ in luteal membranes were not fully characterized. This study was, therefore, undertaken to partially characterize the physicochemical and kinetic properties of $Ca^{++}-ATPase$ system in luteal membranes and microsomal fractions, known as an one of the major $Ca^{++}$ storge sites (Moore and Pastan, 1978), from the highly luteinized ovary Highly luteinized ovaries were obtained from PMSG-hCG injected immautre female rats. Light membrane and heavy membrane fractions and microsomal fractions were prepared by the differential and discontinuous sucrose density gradient centrifugation method desribed by Bramley and Ryan (1980). Light membrane and heavy membrane fractions and microsomal fractions from highly luteinized ovaries are composed of the two different kinds of $Ca^{++}-ATPase$ system. One is the high affinity $Ca^{++}-ATPase$ which is activated in low $Ca^{++}$ concentration (Km, 10-30 nM), the other is low affinity $Ca^{++}-ATPase$ activated in higher $Ca^{++}$ concentration $(K_{1/2},\;40\;{\mu}M)$. At certain $Ca^{++}$ concentrations, activities of high and low affinity $Ca^{++}-ATPase$ are the highest in light membrane fractions and are the lowest in microsomal fractions. It appeares that high affinity $Ca^{++}-ATPase$ system have 2 binding sites for ATP (Hill's coefficient; around 2 in all membrane fractions measured) and the positive cooperativity of ATP bindings obviously existed in each membrane fractions. The optimum pH for high affinity $Ca^{++}-ATPase$ activation is around S in all membrane fractions measured. The lipid phase transition temperature measured by Arrhenius plots of high affinity $Ca^{++}-ATPase$ activity is around $25^{\circ}C$. The activation energies of high affinity $Ca^{++}-ATPase$ below the transition temperature are similar in each membrane fractions, but at the above transition temperature, it is the hightest in heavy membrane fractions and the lowest in microsomal fractions. According to the above results, it is suggested that intracellular $Ca^{++}$ level, which may regulate the luteal function, may be adjusted primarily by the high affinity $Ca^{++}-ATPase$ system activated in intracellular $Ca^{++}$ concentration range $(below\;0.1\;{\mu}M)$.