• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1375-1380
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• 2021

Korea's security response to application service app is still insufficient due to the initial opening of the public safety network. Therefore, preemptive security measures are essential. In this study, we proposed to establish a 'public safety network app security system' to prevent potential vulnerabilities to the app store that distributes app in public safety network and android operating system that operate app on dedicated terminal devices. In order for an application service app to be listed on the public safety network mobile app store, a dataset of malicious and normal app is first established to extract characteristics and select the most effective AI model to perform static and dynamic analysis. According to the analysis results, 'Safety App Certificate' is certified for non-malicious app to secure reliability for listed apps. Ultimately, it minimizes the security blind spots of public safety network app. In addition, the safety of the network can be secured by supporting public safety application service of certified apps.

• Journal of Chest Surgery
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• v.38 no.9 s.254
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• pp.601-608
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• 2005

Background: To maximize the histological advantage and minimize the physiological disadvantage, we have been using the skeletonized gastroepiploic artey (GEA) as a free graft for total arterial revascularization. The aims of the current study was to assess the efficacy of the skeletonized GEA as a composite or extended graft for total arterial revascularization. Material and Method: Between January 2000 and Feburary 2005, 133 patients (43 female, mean age=61.8 yrs) undergoing coronary artery bypass grafting (CABG) with a skeletonized GEA as free graft (22 extended, 107 composite and 4 others) were enrolled in this study. Coronary angiograms were performed in the immediate (median 44 days, n=86), early (median 366 days, n=56) and midterm (median 984 days, n=29) postoperative periods. Result: There were 3 ($2.2\%$) early and 4 ($3.3\%$) late cardiac-related deaths. The mean number of distal anastomoses per patient was 3.34 for total graft and 1.92 for GEA graft. The immediate, early, and midterm GEA patency were 157/159 ($98.7\%$), 106/142 ($94.6\%$), and 53/56 ($94.6\%$), respectively. During follow-up, four patients required percutaneous intracoronary intervention because of GEA and target coronary artery stenosis or competitive flow. Conclusion: These data demonstrate satisfactory clinical and angiographic results in the skeletonized GEA as free graft for total arterial revascularizatioh. Although we need a careful longer follow-up, the skeletonized GEA as a free graft will be a valuable option 'to be' for CABG.

• Korean Journal of Animal Reproduction
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• v.23 no.1
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• pp.63-68
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• 1999

A 4-year old Korean-native cow of third parturition delivered an deformed calf with congenital anasarca and hypoplasia of the extremity at Muan County in Chonnam Province. At parturition, the dam showed amniotic fluid approximately two times more than that at the normal and also occurred severe dystocia. The anomaly died before parturition was 82 cm long and weighed 25 kg. It was difficult to recognize the neck and face of the anomaly due to severe edema and the stretched tongue through mouth was found. The shape of the extremity was recognizable and the systemic hypoplasia of the body with marked edema was found. At necropsy, there was a large amount of serous fluid both in pleural and peritoneal cavity. Also the fluid was contained some of yellowish granular materials and diffusely was fulfilled in all subcutaneous tissue. There was a partial opening in diaphragm which was resulted in the protrusion of approximately half of liver toward peritoneal cavity. There were two kidneys (15${\times}$21 and 13${\times}$18 cm) on the left which were enlarged and relatively larger than the right one (13${\times}$9 cm). In addition, there were found slight to moderate hepatomegaly and splenomegaly with slight congestion, and diffuse edema of intestinal serosa. Lung (32${\times}$49 mm) with marked hypoplasia was smaller than the size of heart (56${\times}$45mm). Serological test to the dam showed relatively high antibody titer (＞64) to Akabane virus which might be involved in the outbreak of the deformed Korean-native calf as one of many causative agents.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.181-181
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• 2011

도로는 국내 물류를 담당하는 중요한 기반시설로 국내 경제성장의 중추적인 역할을 담당하고 있다. 특히, 1970년대 개통된 경부고속도로는 우리나라의 대동맥으로 산업 성장의 파급효과를 가져오는 기반이 되었고, 공학적인 차원에서도 도로 포장재료를 경험 및 과학적으로 분석하여 적용하는 계기로 도로공학발전의 초석이 되었다. 과거에 적용된 도로 포장재료는 기술자의 경험에 의존하여 배합설계가 진행되었으며, 중차량의 비중이 많은 지역은 강성포장을 적용하고, 상대적으로 중차량이 적은 구간은 연성포장을 적용하는 설계를 따랐다. 하지만, 강성포장을 대표하는 시멘트 콘크리트 포장은 시공상의 복잡함과 시멘트 콘크리트 특성상 강도발현을 위해서 일정기간 이상의 양생일수가 필요하므로, 도로건설의 인프라 구축이 시급한 지역에서는 사용의 제약이 따른다. 연성포장을 대표적하는 재료로는 아스팔트 콘크리트 포장을 들 수 있다. 강성포장보다는 상대적으로 시공상의 편리함과 일정기간의 양생이 필요하지 않아 도로 포장재료로서 그 적용성이 우수하다. 과거에는 아스팔트 콘크리트 포장의 종류가 단순화되어 표층, 기층에 대표되는 몇몇 혼합물이 도로 포장재료로 사용되었다. 도로공학의 학문적 발달과 함께 도로포장의 전반적인 기술이 향상되고 있다. 과거의 도로 기능은 국가 경제발전을 위한 산업용 원자재의 운반이 주요 기능을 담당하고 있는 반면, 국민의 경제적 수준이 증대되고 자가용의 보급이 보편화되면서 도로 이용의 주체가 국민 개개인으로 변화되고 있고, 그 요구조건도 다양화되고 있다. 이에 발맞추어 도로공학의 기술적 향상으로 다양한 기능을 발휘할 수 있는 도로포장재료가 개발되고 있으며, 대표적인 제품으로는 배수성 포장, 반강성 포장, 보수성 포장, 탄성 포장, 저소음 포장 등이 있다. 본 연구에서는 기능성 포장의 하나인 저소음 포장의 특성 중 생산성능을 평가하였다. 생산성능이란 저소음포장을 현장 플랜트에서 생산하였을 경우의 특성을 분석하는 과정으로, 실내 실험으로 최적화된 재료의 배합은 이상적인 조건을 적용하여 결정된 것으로 입고된 현장 골재 및 생산 플랜트 조건에 따른 그 배합 및 물성이 변동을 가져올 수 있다. 특히, 저소음 포장은 기존의 아스팔트 포장과 달리 적용되는 골재, 아스팔트의 재료가 고성능을 발휘하기 위하여 특수한 재료를 적용해야 한다. 배합설계에서도 개립도 아스팔트 혼합물에 적용되는 내구성분석 절차를 따라야 하므로, 실내 배합설계 혼합물과 현장 생산 혼합물간의 물리적 특성에 차이를 나타낼 수 있다. 따라서, 본 연구에서는 실내 및 현장 혼합물의 전반적인 물리적 특성의 차이를 분석하여 저소음 포장의 현장 생산성능을 확인하였다. 분석요소로는 혼합물의 기초물성면에서는 밀도, 공극률을 분석하였으며, 실내 내구성면에서는 마샬안정도, 잔류안정도를 분석하여 실내 및 현장 혼합물의 물성차이를 분석하였다. 기초물성을 평가할 수 있는 밀도와 공극률에서는 생산 현장 혼합물이 실내 혼합물 보다 높은 밀도와 낮은 공극률을 나타내고 있으며, 이에 상관하여 강도특성을 분석할 수 있는 마샬안정도도 생산 현장 혼합물이 다소 높은 강도를 발휘하였다. 또한, 수분에 대한 안정성을 평가하는 인자인 잔류 안정도에서는 실내 및 현장 혼합물 모두 우수한 성능을 발휘하였다.

• KDI Journal of Economic Policy
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• v.35 no.4
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• pp.31-61
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• 2013

The purpose of this study is to calculate the economic value of transport demand forecasting risks in the road PPP project. Under the assumption that volatility of the road PPP project value occurs only in regard with uncertainty of traffic volume forecasting, this study calculates the economic value of the traffic forecasting risks in the case of the road PPP project. To that end, forecasted traffic volume is assumed to be a stochastic variable and to follow the Geometric Brownian motion as time passes. In particular, this study attempts to differentiate itself from existing studies that simply use an arbitrary assumption by presenting the application of different traffic volume growth volatility and the rates before and after the ramp-up period. Analysis of the case projects reveals that the risk premium related to traffic volume forecast of the project turns out as 7.39~8.30%, without considering option value-such as minimum revenue guarantee-while the project value volatility caused by transport demand forecasting risks is 17.11%. As the discount rate grows higher, the project value volatility tends to decrease and volatility in project value is always suggested to be larger than that in transport volume influenced by leverage effect due to fixed expenditure. The market value of transport demand forecasting risk-calculated using the project value volatility and risk premium-is analyzed to be between 0.42~0.50, implying that a 1% increase or decrease in the transport amount volatility would lead to a 0.42~0.50% increase or decrease in risk premium of the project.

• Journal of Cadastre & Land InformatiX
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• v.49 no.2
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• pp.135-149
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• 2019

This article analyzed economic effects of changes in spatial accessibility on regional touruism expenditure structure resulting from highway investments on Gangwon province, Korea. The Seemingly Unrelated Regress(SUR) model is applied to analyze the structure of change in tourism expenditure of Gangwon Province, and the competition and complementary relationship of tourist demand were analyzed among 18 counties in Gangwon by Dendrinos-Sonis method. The spatial accessibility has a significant effect on the increase in amount of tourist expenditure, but by 1% increase in the accessibility resulted in a reduction of length of stay -0.18% and travel costs -0.34% by respectively. The most powerful variable for improving the on-site economy is the tourist service establishment, which increases one unit, the amount of tourist expenditure increased by 3.6%. Moreover, the competition and supplemental relationship of tourism demands in Gangwon was decided by the conditions under which traffic flow with passing occurred, such as inland or ocean-typed travel attractions, adjacent or remote regions to the highway. The limitations of this study were not able to use raw data of tourism expenditures before and after the opening the highway due to the restriction of priority data, and further research on the appropriate level of spatial accessibility for the regional economy is needed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.27-36
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• 2010

Recently, the management of metro business in large cities has become more difficult because of increased construction and operation costs. The purpose of this paper presents the construction of transfer system to resolve about recent tendency to decrease of metro-users and diminution of use efficiency which are serious problems of Busan metro. To cope with this situation, it is necessary to examine the methods of obtaining returns on development profits of land value rises that occur due to transfer system construction between Busan metro line #1 and line #2 in Yangsan area. Therefore, it was made use of research on metro utilization to presuppose service improvement, as an alternative, in the transfer system construction between metro and metro which might be powerful influence over metro-users. In this research, it was examined the actual situation of rises in land values brought about by the transfer system construction of metro line #1 and line #2 in Yangsan area with application of four (4) methods, and have calculated a basis of the development profits produced by the transfer system construction of metro line. According to the economical efficiency analysis, the total construction cost amount to 4,827.1 billion won of case #1 based on single track, and evaluate economically as B/C to 1.013, NPV to 72.7 billion, IRR to 5.614 percent.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.50-57
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• 2017

This study investigated the causes and problems of train operation impediments through the statistics analysis of 8 years'internal data of Daejeon Metropolitan Express Transit. By evaluating the risks regarding the system, equipment, and parts of high risk group, this study measured the Risk Index Severity, and applied the $5{\times}5$ Risk Assessment Matrix which is a method of risk management to calculate the scale of risk to analyze the safety level and allowance range. As a result, the car sector, the most serious risk, followed by machinery and equipment sector showed that the inherent risk. In particular, the door broken and the door rail signaling and control devices due to defects of the vehicle is high, but also the severity, and frequency are showing very frequent additional potential accidents. PSD also had defects in the machinery sector appeared to be the most dangerous of the PSD poor safety gates, it was found that the glass also involve the risk of mishandling and breakage of the PSD. This study intended to contribute to the transportation benefits through the safety and stable operation of Metropolitan Express Transit.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.7-14
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• 2006

Most researches about rumble strips have Presented only the before-and-after analysis of the accidents. So, Researchers have not dealt with the estimation of rumble strip's effectiveness on the driver's alertness. In this study. the effectiveness of the rumble strips on the driver's alertness was estimated by measuring the bio-signal transmitted from the driver. The bio-signal acquired for this experiments were theta wave in central lobe. The experimental results revealed that the theta waves as measured form the drivers's head while in the rumble strip section differed from those while in non-rumbled section; 74 percent decrease in theta wave value, respectively. This fact finding could mean that the driver's alertness increased from 74 percent while in the rumble strip section of the road. In all five trials of driving experiments on the rumble strip section, all the drivers showed the best alertness as measured by the theta waves in the first driving trial.

• Journal of the Economic Geographical Society of Korea
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• v.7 no.2
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• pp.283-296
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• 2004

This study aims at explaining locality of living space which is changing drastically by exploring change of land utilization, living space and condition in Yeo-ju, an agricultural area around Seoul. The conclusions are as follows. 1. Agricultural land utilization tends to decrease, while civic land utilization tends to increase. 2. Change of living space due to transportation development is remarkable. Big ferry town (Yeoju-town) grew to a city, while small ferry town fell away. 3. In villages on slow urbanization, houses or lands are deserted. 4. In villages, there has been increasing number of recreational farm for urbanite. 5. In 80% of villages, there has been an increasing number of part-time farmers. 6. Most serious social problem in Yeo-ju is incompetence in agricultural activity after UR. In sum, Yeoju is now an area where the pace of urbanization is very tardy. However, this area, as an changeable area just before speedy urbanization, is expected to be urbanized drastically on condition that transportation develop. When plans suitable for this town are set up, Yeoju is expected to be a comfortable city.