Improved TOA-Based Localization Method with BS Selection Scheme for Wireless Sensor Networks

고성열,정정화 한국전자통신연구원 2015 ETRI Journal Vol.37 No.4

The purpose of a localization system is to estimate the coordinates of the geographic location of a mobile device. The accuracy of wireless localization is influenced by non-line-of-sight (NLOS) errors in wireless sensor networks. In this paper, we present an improved time of arrival (TOA)–based localization method for wireless sensor networks. TOA-based localization estimates the geographic location of a mobile device using the distances between a mobile station (MS) and three or more base stations (BSs). However, each of the NLOS errors along a distance measured from an MS (device) to a BS (device) is different because of dissimilar obstacles in the direct signal path between the two devices. To accurately estimate the geographic location of a mobile device in TOA-based localization, we propose an optimized localization method with a BS selection scheme that selects three measured distances that contain a relatively small number of NLOS errors, in this paper. Performance evaluations are presented, and the experimental results are validated through comparisons of various localization methods with the proposed method.

경영자능력이 내재자기자본비용에 미치는 영향

고성효,고창열,고봉조 한국회계정보학회 2015 회계정보연구 Vol.33 No.4

The purpose of this study is to investigate an effect of managerial ability on the implied cost of equity capital. We also examine how a relation between managerial ability and the implied cost of equity capital is affected by information asymmetry. We measure managerial ability based on prior studies of Demerjian et al.(2012). Our result show that managerial ability are negatively related to the implied cost of equity capital. High managerial ability is significantly associated with lower implied cost of equity capital. We also find that firms with lower information asymmetry have a larger decrease in the cost of capital. Our study is distinguished from prior studies because we empirically analyze the evidence that a relation between managerial ability and the implied cost of equity capital. In addition we find empirical evidence that a relation between managerial ability and the implied cost of equity capital is affected by information asymmetry. Overall our study implicates the importance of managerial ability in terms of investment and financing decision making. 본 연구는 2000년부터 2014년까지 유가증권에 상장된 기업을 대상으로 경영자의 능력과 내재자기자본비용의 관계를 실증분석하였다. 선행연구에서 기업의 내재자기자본비용은 기업의 사회적 책임활동의 수준, 정보비대칭, 발생액 변동액 등에 영향을 받는다고 하였고 경영자의 능력이 보수주의, 회계정보의 질, 조세회피의 수준에 영향을 미친다고 하였으나 경영자능력이 내재자기자본비용과 어떠한 관련성을 가지는지에 대해서는 보고된 바 없다. 본 논문에서는 Demerjian et al.(2012)이 제시한 경영자 능력 측정치를 이용하여 경영자능력이 내재자기자본비용에 어떠한 영향을 미치는 지를 분석하였다. 본 연구의 주요 분석결과는 다음과 같다. 첫째, 경영자의 능력이 높을수록 내재자기자본비용은 감소하는 것을 확인하였다. 이러한 결과는 기업을 경영하는 경영자의 능력이 높을수록 외부이해관계자들은 미래 경영성과와 현금흐름에 대해 불확실성을 낮게 인식하여 내재자기자본비용을 낮게 요구하는 결과라 해석할 수 있다. 둘째, 정보비대칭이 작은 집단에서는 경영자의 능력과 내재자기자본비용 사이에 유의한 음(-)의 관계가 있음을 실증하였다. 반면 정보비대칭이 큰 집단에서는 경영자의 능력과 내재자기자본비용 사이에 통계적인 유의성은 검증되지 않았다. 이러한 결과는 정보비대칭이 큰 상황에서는 경영자의 능력과 관계없이 내재자기자본비용이 결정되지만 정보비대칭이 작은 상황에서는 외부이해관계자들이 경영자의 능력을 충분히 인지하여 내재자기자본비용에 유의적인 음(-)의 영향을 미침을 의미한다. 본 연구는 경영자능력과 내재자기자본비용간의 관계를 분석함으로써 경영자능력이 기업가치에 기여하는 추가적인 경로를 파악하였다는 점에서 의의가 있다. 또한 본 연구의 분석결과 투자안에 대한 평가시 경영자의 능력에 따라 할인율이 달라질 수 있음을 확인하였다. 이러한 결과는 경영자의 능력이 기업의 투자 및 재무의사결정에 지대한 영향을 미칠 수 있음을 시사한다.

초록집 ( 1993 . 4 . 15 ) : 1993 년도 신약개발 연구결과 / 미발표 결과 목차 ; Rifampicin 에 내성인 Bifidobacterium bifidum 균주 개발

최응칠,고성열,김병각 한국응용약물학회 1993 학술대회 Vol.1993 No.1

외국인 근로자의 주거실태에 관한 연구

하성규(Ha, Seong-Kyu),고성열(Koh, Seong-Yeol) 대한부동산학회 2006 大韓不動産學會誌 Vol.24 No.1

본 연구의 목적은 외국인 근로자의 주거실태를 파악하고 이들 근로자들의 주거권 보장 및 주거빈곤을 해결하기 위한 방안을 모색하고자 한다. 이를 위해 경기도 안산시를 대상으로 외국인 근로자의 주거실태를 파악하고, 이 조사를 통해 얻은 자료를 우리나라의 최저주거기준과 비교하여 주거실태를 분석하였다. 2005년 현재 외국인 근로자는 35만 8천명에 달하고 있다. 근로자의 상당수는 불법 체류상태이며 열악한 주거환경에서 집단적으로 생활하거나, 컨테이너ㆍ공장 등의 비주거용 건물등의 최저주거기준 이하의 주거환경 속에서 살아가고 있다. 이와 같은 외국 근로자의 주거빈곤은 유엔에서 결의한 인간의 기본적 권리인 주거권이 보장되지 못하고 있음을 나타내는 것이고 생명에 위협을 받거나 사회적 편견과 갈등을 유발하는 요인이 되고 있다. 이를 극복하기 위한 방안으로는 첫째, 외국인 고용정책에 주거에 대한 법적 보완이 필요하며. 둘째, 이와 관련하여 지방자치단체 및 NGO의 자발적 참여가 활성화 되어야 한다. 주거권과 시민권적 관점에서 외국인 근로자는 그 지역에 거주하고 있는 동등한 시민으로 바라보아야 할 것이다. 셋째, 외국인 근로자의 주거실태조사, 다양한 연구, 그리고 정책적 관심이 요구되고 있다. The purpose of this study is to examine the housing conditions of foreign workers who are working here in Korea and to present policy suggestions. For this purpose, a housing survey of foreign workers’ accommodation in Ansan city was made, and their housing condition was compared with the minimum housing standard which was set up by the government in 2004. In Korea, the population of foreign workers is 358,000 as in 2005, and they are mostly engaged in so called 3D jobs(danger, difficult, dirty). Their housing condition were filthy and mostly substandard such as container, tents, illegal temporary accommodations. The survey demonstrates 64% of respondents are illegal aliens. They are facing a serious housing shortage and lack of affordability. In terms of housing rights for foreign workers in Korea the government should make first a housing condition survey of foreign workers in order to find out housing situation. The government has to set up a policy guideline on housing for the foreign workers and the housing minimum standard should be applied to the foreign workers housing in light of humanitarian considerations. NGOs and CBOs’ activities should be expanded for the improvement of foreign workers’ housing conditions. It is also necessary to review and research on housing policies of foreign workers in advanced countries.

Mountain-Cultivated Ginseng Attenuates Phencyclidine-Induced Abnormal Behaviors in Mice by Positive Modulation of Glutathione in the Prefrontal Cortex of Mice

The-Vinh Tran,신은주,고성권,남윤성,정윤희,정지훈,장춘곤,나성열,Kiyofumi Yamada,Toshitaka Nabeshima,변재경,김형춘 한국식품영양과학회 2016 Journal of medicinal food Vol.19 No.10

Escalating evidence indicates that ginseng treatment protects against psychotoxic behaviors and memory impairment. Although the underlying mechanism of schizophrenia remains elusive, recent investigations proposed that downregulation of glutathione (GSH) can be involved in the pathogenesis of this disorder. Since little is known about the effects of ginseng in a schizophrenia-like animal model, we selected mountain-cultivated ginseng (MG) from a variety of ginseng extracts to investigate the effect of ginseng on the psychosis induced by phencyclidine (PCP) in mice. PCP (10 mg/kg/day, s.c.) was administered for 14 consecutive days. Novel object recognition, forced swimming, and social interaction tests were performed during the withdrawal period of 7 days. In addition, behavioral sensitization to an acute challenge of PCP was evaluated. The parameters of the GSH-dependent system in the prefrontal cortex (PFC) were examined. MG (200 mg/kg, i.p./day) or antipsychotic clozapine (10 mg/kg, p.o./day) was administered for seven consecutive days after the final PCP treatment. PCP significantly produced abnormal behaviors, followed by increases in Nrf2 nuclear translocation, its DNA binding activity, and glutamate–cysteine ligase (GCL) mRNA expression in the PFC. PCP treatment significantly decreased GSH/glutathione disulfide (GSSG) ratio and glutathione peroxidase (GPx) activity. MG significantly attenuated abnormal behaviors and the decreases in GSH/GSSG ratio and GPx activity induced by PCP. MG attenuated the increases in Nrf2 activity and GCL expression caused by PCP. The protective potentials of MG were comparable to those of clozapine. MG ameliorates PCP-induced schizophrenia-like psychosis in mice through the positive modulation of the glutathione system.

리팜피신에 내성인 Bifidobacterium bifidum 균주개발

최응칠(Eung Chil Choi),고성열(Sung Youl Ko),김희선(Hee Sun Kim),최성숙(Sung Sook Choi),김숙경(Sook Kyung Kim),김병각(Byoung Kak Kim) 대한약학회 1993 약학회지 Vol.37 No.5

Bifidobacterium bifidum, one strain of medical preparations being on the market for human intestinal disorder, is very sensitive to rifampicin. If this preparation is taken with rifampicin, its therapeutic effect can't be expected. To develope rifampicin resistant mutants, B. bifidum was treated with N-methyl-N''-nitro-N-nitrosoguanidine(MNNG). All of thirty strains grown on the plates containing 10 mcg/ml rifampicin were over 1,000 times more resistant to rifampicin than parental strain and they were identified as B. bifidum by fructose-6-phosphoate phosphoketolase test. Three strains out of thirty, which produced almost same amount of organic acid as parental strain, were selected for further studies. They showed identical growth inhibition activity aganist E. coli compared with that of parental strain. And rifampicin was not inactivated.

신경망을 이용한 광주광역시의 일반폐기물량 예측

이경훈(Rhee Kyoung Hoon),김태경(Kim Tae Kyoung),양치열(Yang Chi Yeol),고성석(Go Seoung Seouk) 대한토목학회 2002 대한토목학회 학술대회 Vol.2002 No.11