A Case Study on Fault Tolerant Control System for Power Plant Boiler Controller

김지홍,조현용,정명진,변증남,Kim, Jee Hong,Cho, Hyun Yong,Chung, Myung Jin,Bien, Zeungnam The Institute of Electronics and Information Engin 1987 전자공학회논문지 Vol.24 No.1

As a means of improving the reliability of a process control system, a FTCS(Fault Tolerant Control System) is designed and applied to the boiler controller of a thermal power plant. The proposed FTCS has capabilities of fault detection and diagnosis as well as back-up control and bumpless switching. A prototype of FTCS is implemented on an IBM PC as an add-on system and it is experimentally verified by using a boiler process simulator together with simplified analog controllers and a switching unit that an one-fold fault is detected in real time and back-up controller takes over the role of the original controller, controlling the faulty loop.

PA Map(Pulse Analysis Map)을 이용한 새로운 부분방전 패턴인식에 관한 연구

金智鴻(Ji-Hong Kim),金正泰(Jeung-Tae Kim),金鎭基(Jin-Gi Kim),具滋允(Ja-Yoon Koo) 대한전기학회 2007 전기학회논문지 Vol.56 No.6

Since one decade, the detection of HFPD (High frequency Partial Discharge) has been proposed as one of the effective method for the diagnosis of the power component under service in power grids. As a tool for HFPD detection, Metal Foil sensor based on the embedded technology has been commercialized for mainly power cable due to its advantages. Recently, for the on-site noise discrimination, several PA (Pulse analysis) methods have been reported and the related software, such as Neural Network and Fuzzy, have been proposed to separate the PD (Partial Discharge) signals from the noises since their wave shapes are completely different from each other. On the other hand, the relevant fundamental investigation has not yet clearly made while it is reported that the effectiveness of the current methods based on PA is dependant on the types of sensors. Moreover, regarding the identification of the vital defects introducible into the Power Cable, the direct identification of the nature of defects from the PD signals through Metal Foil coupler has not yet been realized. As a trial for solving above shortcomings, different types of software have been proposed and employed without any convincing probability of identification. In this regards, our novel algorithm "PA Map" based on the pulse analysis is suggested to identify directly the defects inside the power cable from the HFPD signals which is output of the HFCT and metal foil sensors. This method enables to discriminate the noise and then to make the data analysis related to the PD signals. For the purpose, the HFPD detection and PA (Pulse Analysis) system have been developed and then the effect of noise discrimination has been investigated by use of the artificial defects using real scale mockup. Throughout these works, our system is proved to be capable of separating the small void discharges among the very large noises such as big air corona and ground floating discharges at the on-site as well as of identifying the concerned defects.

에너지 및 성능 효율적인 이종 모바일 저장 장치용 동적 부하 분산

김지홍(Ji-Hong Kim),김영진(Young-Jin Kim) 한국컴퓨터정보학회 2009 韓國컴퓨터情報學會論文誌 Vol.14 No.4

본 논문에서는 운영체제 수준에서 에너지 절감과 함께 I/O 성능 개선을 목적으로 하여 소형 하드 디스크와 플래시 메모리를 이종의 저장 장치로 가지는 모바일 시스템에 대해 동적 부하 분산 기법을 제안한다. 제안 기법은 부하가 에너지 및 성능 효율적인 방법으로 하드디스크와 플래시 메모리의 이종성의 저장 장치 구성에 대해서 어떻게 효율적으로 분산될 수 있을 것인지를 발견하기 위하여 파일 배치 기법과 버퍼 캐시 관리 기법을 결합하는 접근법을 취한다. 제안한 기법은 폭넓은 시뮬레이션을 통해서 기존의 기법들과 비교하여 이종의 모바일 저장장치들에 대해서 더 개선된 실험 결과를 보이는 것으로 나타났다. In this paper, we propose a dynamic load distribution technique at the operating system level in mobile storage systems with a heterogeneous storage pair of a small form-factor and disk and a flash memory, which aims at saving energy consumption as well as enhancing I/O performance. Our proposed technique takes a combinatory approach of file placement and buffer cache management techniques to find how the load can be distributed in an energy and performance-aware way for a heterogeneous mobile storage air of a hard disk and a flash memory. We demonstrate that the proposed technique provides better experimental results with heterogeneous mobile storage devices compared with the existing techniques through extensive simulations.

분산형 전원의 배전계통 연계시 경제적 발전 계획 수립에 대한 연구

김지홍(Ji Hong Kim),정현수(Hyeon Soo Jung),김진오(Jin O Kim) 대한전기학회 1999 대한전기학회 학술대회 논문집 Vol.1999 No.7

디지털 프린팅 시스템의 활용 : 디지털 날염 시스템 관련 디자인 및 교육

김지홍 ( Jin Hong Kim ),권택균 ( Taek Kyun Kwon ) 한국의류학회 2007 패션정보와 기술 Vol.4 No.-

장애인 구강건강관리인력에 따른 구강환경관리능력 지수 비교

김소연,김수지,김연선,김지홍,김효진,정승민,홍지희,Kim, So-Yeon,Kim, Su-ji,Kim, Yeon-seon,Kim, Ji-Hong,Kim, Hyo-Jin,Jung, Seung-min,Hong, Ji-Hee 대한심미치과학회 2019 Journal of the Korean Academy of Esthetic Dentistr Vol.28 No.2

Objectives: 현재 장애인의 구강건강은 구강건강전문인력인 치과위생사가 아닌 사회복지사가 책임지고 있는 실정이다. 장애인 복지시설에 상주하는 사회복지사에게 올바른 구강건강 관리방법을 제공함으로써 장애인 구강건강의 형평성 제고를 도모하고자 한다. Methods: 2019년 4월 13일부터 2019년 4월 20까지 서울시 송파구에 위치한 'o' 장애인 복지시설에 거주하는 1급 지적장애인을 대상으로 식후 치과위생사 4명과 사회복지사 4명이 잇솔질 시행 후 구강환경관리능력지수(PHP Index)를 측정하여 비교하였다. 사전에 사회복지사 4명에게 잇솔질(회전법)을 교육하였으며, 잇솔질 방법과 검사 측정 도구를 통일하였다. 대상자의 구강보건지식을 평가하기 위해 자기기입식 설문지를 사용하였고, 구강보건지식점수 및 구강환경관리능력지수(PHP index) 점수의 평균, 대상자의 일반적 특성에 대해 Microsoft Office Excel ver.2016 을 이용하여 빈도 및 백분율 산출하였다(N%). Results: 치과위생사와 사회복지사의 구강보건지식 조사에서 모든 문항에서 치과위생사가 높은 점수를 나타냈다. 치과위생사와 사회복지사가 지적장애인을 대상으로 잇솔질(회전법) 실시 후 구강환경관리능력지수(PHP Index)를 비교했을 때 연령별, 성별 모든 분류에서 치과위생사의 구강환경관리능력지수(PHP Index)가 낮게 나타났다. 2차에 걸쳐 치과위생사와 사회복지사가 지적장애인을 대상으로 잇솔질(회전법) 실시 후 구강환경관리능력지수(PHP Index)를 비교했을 때 1차, 2차 모두 치과위생사의 구강환경관리능력지수(PHP Index)가 낮게 나타났다. Conclusions: 이상의 결과를 종합해 볼 때, 장애인들의 구강건강관리를 위해 치과위생사가 사회복지사보다 구강건강관리능력이 더 효율적인 것으로 나타났다. 따라서 장애인들의 입소시설에 치과위생사가 구강건강관리전문 인력으로 배치되어 장애인 및 사회복지사의 교육을 담당할 수 있는 환경이 조성되어야하며, 치과위생사를 양성하는 대학의 교육과정에도 장애인의 특성을 이해하는 교과목이 개설되어 전문성이 제고되어야 한다. Objectives: Currently, oral health of the disabled is taken care of by the social workers, not by dental hygienists, who are the oral health professional in this area. Therefore, we aim to enhance the equity of oral health for the disabled by providing the correct oral health care method to social workers residing in the welfare facility for the disabled. Methods: Four dental hygienists and four social workers were given the class I intellectual disabilities living in 'o' welfare facilities for disabled people in Songpa-gu, Seoul from April 13, 2019 to April 20, 2019. Patient Hygiene Performance(PHP) Index were measured and compared. In advance, the social workers were taught brushing (Rolling method), and the method of brushing and measuring tools were integrated. Results: Twice a total of dental hygienists and social workers practiced toothbrushing(Rolling method) for the class I intellectual disabilities who is a person to be brushed. When comparing the Patient Hygiene Performance(PHP) Index after the second round, the result shows that both the first and second dental hygienists' Patient Hygiene Performance(PHP) Index is lower. Conclusions: Comparing oral health knowledge level and Patient Hygiene Performance(PHP) index of dental hygienist and social workers, the result shows that dental hygienist has higher oral health care ability. Therefore, the dental hygienist should be placed in welfare facility for the disabled as an expert in oral health management to create an environment in which the disabled and social workers can be trained. In addition, the curriculum of the college that nurtures the dental hygienists should have a course to understand the characteristics of the disabled person in order to enhance the professionalism of dental hygienists.

천연활엽수림의 세가지 조림작업종에 따른 천연갱신 양상

김지홍(Ji Hong Kim),양희문(Hee Moon Yang),김광택(Guang Ze Jin) 한국산림과학회 1999 한국산림과학회지 Vol.88 No.2

The natural regeneration pattern was evaluated for 11 useful hardwood species in the natural deciduous forest where three different silvicultural practices (two-storied system, shelterwood system, and selection system) were applied and passed by three growing seasons. The study forest was presently dominated by Quercus mongolica in the upper canopy. However, since the analysis indicated that the number of regenerated seedlings of Acer mono and Fraxinus rhynchophylla was fairly abundant enough, these two species were anticipated to have the possibility to be among dominant species along with Quercus mongolica. The results of seedling occurrence after regenerating cutting showed that the number of seedlings was estimated for 3,145/㏊(10 times of overstory) in the two-storied system, 6,885/㏊(9 times of overstory) in the shelterwood system, and 2,275/㏊(4 times of overstory) in the selection system. The estimation was varied by species, and the number of stump sprout was more abundant. The proportion of seedlings was high in 60∼80% of overstory density and 60∼70% of understory coverage, and high in the site of less than 25° of slope and from southwest to northwest of aspect. These results were still varied by species. Stump diameter and height had little influence on the occurrence of sprout.

회계이익변경에 대한 단순투자자의 반응

김지홍 ( Jee Hong Kim ),장진호 ( Jin Ho Chang ),여은정 ( Eun Jung Yeo ) 한국회계학회 2004 會計學硏究 Vol.29 No.3

본 연구는 1998년 초부터 2003년 6월말까지 증권거래소의 전자공시시스템에 회계변경을 공시한 상장기업을 표본으로 하여, 단순투자자의 비율이 높은 기업에서의 회계이익변경에 대한 주가반응을 살펴보았다. 연구 결과, 단순투자자(naive investor)의 대용치로 사용된 개인소액투자자의 지분이 높은 기업에서 회계변경으로 인한 보고이익의 증가가 높을수록 양(+)의 주가반응이 존재함을 발견하였다. 이 결과는 실증회계이론에서 제시한 보고이익의 증가가 계약비용을 감소시키는 효과를 통제한 후에도 유의하였다. 반면, 전문투자자(sophisticated investor)의 대용치로 사용된 기관투자자 및 외국인투자자의 지분이 높은 기업에서는 회계변경으로 인한 이익증가에 유의적인 시장반응이 관찰되지 않았다. 본 연구의 결과는 한계투자자의 전문성에 따라 회계정보에 대한 주가반응이 상이할 수 있다는 확장된 기능적 고착가설(extended functional fixation hypothesis)을 지지하는 결과이다. This study empirically examines whether there is price reaction of the accounting changing companies which have high rate of unsophisticated investors` holdings. That is, this study will analyze whether there is different response to reported earnings changes by accounting change between unsophisticated and sophisticated investors. Most significantly, this study observes the cumulative abnormal returns on the time of disclosing to the accounting change. The final sample consists of 96 listed on the Korean Stock Exchange and disclosed by an Electronic Disclosure System over the period of 1998 to June, 2003. The results of this study are summarized as follows. First, there is positive relation between price reaction of individual investors proxied by naive investors and the reported earnings by accounting changes. This means that unsophisticated investors react naively on the increase of earnings by accounting changes. Second, there is no positive relation between the price reaction of institutional or foreign investors proxied by sophisticated investors and the increasing earnings by accounting changes. This means that sophisticated investors don`t react naively in the increase of earnings by accounting changes. These results supports the extended functional fixation hypothesis that price reactions of the accounting information can be varied according to the marginal investor`s expertise.

연간이익 공시 시점별 시장반응

김지홍 ( Jee Hong Kim ),장진호 ( Jin Ho Chang ),여은정 ( Eun Jung Yeo ) 한국회계학회 2006 會計學硏究 Vol.31 No.2

본 연구는 우리나라 거래소에 상장되어 있는 12월 결산 제조업에 해당하는 기업을 연구대상으로 하여 2000년부터 2003년까지 연간이익 공시시점별 이익정보에 대한 시장반응을 조사함으로써 이익정보 공시일에 대한 정확한 시점을 파악하고자 한다. 이에 이익변동공시일, 주주총회소집통지공시일, 주주총회7일전을 각각의 이익공시시점으로 보고 시장반응을 검증하였다. 연구 결과, 첫째, 이익공시시점별 회귀분석에서는 이익변동공시일에서만 이익정보에 대한 유의적인 주가반응이 나타났다. 둘째, 각 이익공시시점마다 최초공시와 반복공시의 경우를 구분하여 회귀분석한 결과 이익변동공시일과 주주총회소집통지공시일의 최초공시 시점에서 유의적인 주가반응이 나타났으며, 반복공시 시점에서는 주가반응이 모두 유의적이지 않음을 발견하였다. This study examines the accurate disclosure timing of annual earnings. In the United States, the date of earnings disclosure is databased in COMPUSTAT, so most related research is approached with an understanding of this cycle. But Korean researchers have recognized the limitation of their research designs due to paucity of information regarding the accuracy of disclosure timing of annual earnings. Recently, the corporate disclosure environment has gone through tremendous change. First, the DART system was fully implemented. Second, rapid change in earnings compared with the previous fiscal year`s earnings is has been disclosed via the on-line DART system since 2000. Third, with the adoption of Regulation Fair Disclosure (Reg FD) in 2002, the timing of earnings disclosure post-FD is earlier than pre-FD, and the number of earnings releases has increased. The theme of this study is appropriate under these circumstances. Using a sample of 684 Korean firm-year observations that disclose earnings information for the years 2000-2003, this paper empirically examines the accurate disclosure timing of annual earnings. The results of this study are summarized as follows. First, there is no market reaction during the period of rapid change of earnings` disclosures. Second, there is a significant market reaction during the period of rapid change of earnings disclosures and the notice of shareholders` conferences if only the earnings` disclosure is disclosed before the conference. This is not the case if the disclosure is made repeatedly.

국제회계기준(K-IFRS) 도입 금융업 사례연구: 은행업과 손해보험업을 중심으로

김지홍 ( Jee Hong Kim ),박우진 ( Woo Jin Park ),유혜영 ( Hae Young Ryu ) 한국회계학회 2011 회계저널 Vol.20 No.2