Method for Protection of Single‑Line‑Ground Fault of Distribution System with DG Using Distance Relay and Directional Relay

Jung‑Hun Lee,Min‑Su Park,Hong‑Seon Ahn,Kyung‑Won Park,Jun‑Seok Oh,Seung‑Gyu Jeon,Dong‑Kyu Kim,Jae‑Eon Kim 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.4

When large scales DG are connected to the distribution system of unidirectional power currents, bi-directional power currents are formed, making it impossible to use conventional overcurrent protection methods alone to detect and isolate fault sections for ground and short-circuit faults. To solve these problems, this study proposed the method of protection against single-line-ground fault of common neutral line multi-contact local power distribution system using distance relay and directional relay. The proposed protection method was applied to the common neutral multi-ground distribution system to validate the protection against single-line-ground fault through the PSCAD/EMTDC software package and efectively detect and isolate only the zone of single-line-ground fault without malfunctions.

대구시 소방권역별 접근성 분석을 이용한 구조대 재편방안

정규동(Jung Gyu-Dong),홍원화(Hong Won-Hwa),최준호(Choi Jun-Ho),김광섭(Kim Gwang-Seob),이지수(Lee Ji-Soo) 대한건축학회 2012 대한건축학회논문집 Vol.28 No.9

In a fire situation, the priority is fast and safe rescue. Therefore, because of the importance of the role of rescue team, specify the criteria of equipments as act. But it can’t be helped appear vulnerable area according to the problems such as province fiscal conditions and budget. in this study suggest improvement considering the characteristics of the actual road and emergency vehicles through accessibility analysis. In the process of vulnerable area deduction, the area of service area is wider, the larger number of vulnerable buildings. And analyze that especially approximately 77% of the entire are vulnerable buildings. Jung-gu, Daegu, the center of the approach is only 3% of vulnerable buildings, but as a whole of Daegu, Within 5 minutes from the rescue team are difficult to access the building by about 30 percent. In order to improve it, Station of jurisdiction that need to be adjusted or additional installations proposed regional strategy for the reorganization. According to the proposed strategy to evaluate the improvement, vulnerable about the whole building from 140,000 to 70,000 could be reduced by half. Alternative to reduce the vulnerability of buildings according to the percentage reduction in overall approximately 30-16% can be reduced. If use the result of study, it will be able to set priorities of expansion of rescue team, and utilized to predict macroscopic vulnerable area in Daegu city.

신홍균(申洪均:改名申屹,申矻)한의사의 생애와 독립운동

정상규(Jung Sang Gyu),신민식(Shin Min Shik) 한국의사학회 2021 한국의사학회지 Vol.34 No.1

ShinHong-GyunandhisfamilyhavebeeninmedicineformanygenerationsasKoreanMedicalDoctors(KMDs).In1919whenShin Hong-GyunwasparticipatinginanindependencemovementinJang-Baek-Hyun,hisyoungerbrotherShinDong-Gyunwaskilledby Japanesemilitarypoliceforces.ThistragicincidenttriggeredShinHong-Gyuntoestablishanarmyfornationalindependencecalled <Dae-JinDan>,holding200youngmen,toserveinarmedstruggleagainsttheJapaneseGovernmentwithKim Jung-GeoninMay,1920. InMarch1933,ShinHong-Gyun,asamilitarysurgeon,ledhismentotheKoreanIndependenceArmytofightabattle.Oncehebecame amemberoftheKoreanIndependenceArmy,he,infact,participatedinfewbattles:Sadohaja,Dong-Kyung-Sung,Deajeonjayeong. DaejeonjayeongwasawaypointthattheJapanesemilitaryneededtopassthroughinordertoreachtheWangcheongarea.Shin Hong-Gyun’sindependenceforceshadtoendurepainfulstarvationandheavyrainwhilehidinginambushforlongperiodsoftimeuntil theJapanesemilitarywouldappear.Duetoitssummerrainyseason,rainwateroverflowedintotheirtrenchesandwasfilleduptothe waist.Evenworse,foodstockpileswerelow andtheJapanesearmydidnotappearforlongertime.ShinHong-Gyun’sentireteam sufferedseverehungerandextremecold. Atthiscriticalmoment,Shin Hong-Gyun used hisexpertiseasa KMD tofind edibleblackmushroomsthatgrow wild in the mountainsandusethem tofeedhismen.ThiseventledtothevictoryoftheindependencearmyatthebattleofDaejeonjayeong. Thepurposeofthepaperistoinform andhighlighttheforgottenhistoryofShinHong-Gyunwhowas,both,aKoreanMedical Doctorandamilitarysurgeon.

도시열섬현상 완화를 위한 녹지네트워크 및 바람길 구축

차재규 ( Jae Gyu Cha ),정응호 ( Eung Ho Jung ),류지원 ( Ji Won Ryu ),김대욱 ( Dae Wuk Kim ) 한국지리정보학회 2007 한국지리정보학회지 Vol.10 No.1

현대의 도시는 살아있는 생명체처럼 매일 변화를 거듭하고 있다. 이전과 달리 집중된 공간에서 짧은 시간동안 일어난 공간의 변화는 도시환경을 악화시켜 환경문제를 유발하였다. 특히 지표면 및 토지이용의 변화 등으로 발생된 도시열섬현상은 도시민의 건강과 경제적인 손실 등 사회문제로 대두되고 있다. 이러한 도시열섬현상을 해결하기 위한 도시계획적 접근방법의 하나가 녹지네트워크의 도입이다. 본 연구에서는 대구광역시 중구와 남구를 사례대상지로 선정하여 도시열섬현상 분석, 토지피복분류, 녹지네트워크 연계가능성 분석, 바람길 분석을 통하여 녹지네트워크 구축을 제안하였다. 연구결과 남쪽의 앞산 및 산지지역을 녹지네트워크의 핵, 두류공원 및 달성공원 등 남구 2개 지역과 중구의 6개 지역의 근린공원을 거점으로 하고 학교부지와 공원시설 등을 포함하는 지역을 거점 가능지역으로 설정하여 대상지역의 광역 및 세부 그린네트워크 구축을 제안하였다. 특히 앞산과 연결되는 캠프워커는 핵과 연결되고 있는 거점지역으로서 향후 미군부대 이전 후에 반드시 보전되어야 할 지역으로서 판단된다. 또한 녹지네트워크를 통해 바람길을 확보하기 위하여 중구의 수성교 인근과 남구의 캠프워커지역을 바람통로확보지구를 설정하는 것이 바람직할 것으로 판단된다. Like other organic beings, modern cities change every day. Unlike in the past, changes of space which have been taking place in concentrated spaces during short periods of time have worsened the environment of cities creating environmental problems. In particular, the urban heat-island phenomenon, which is caused by changes in using the earth`s surface, has emerged as a key social issue along with health problems and economic difficulties. The Green Network has been introduced as an urban planning approach to solve the urban heat-island phenomenon. This study suggests constructing a Green Network through analyzing the urban heat island phenomenon, land cover classification, and linkage possibility with the Green Network and wind corridors by researching Jung-Gu, and Nam-Gu in Daegu Metropolitan City. In conclusion, this study presented the construction of a broad and detailed Green Network of object areas by assigning Apsan to the southern area and mountain area as the core, two areas of Nam-Gu and six areas of Jung-Gu such as Duryu Park and, Dalsung Park as footholds and other school land and park facility areas as footholds-to-be areas. In particular, Camp Walker, which is connected with Apsan, is not only a foothold but connected to the core, is necessary to preserve after being transferred from the U.S. Army. In addition, assigning the Susung Bridge area of Jung-Gu and the Camp Walker area of Nam-Gu as the wind corridor areas is recommended.

일본·미국·독일 학술연구 지원기관의 학회지원 비교연구

김성열,고창규,정규영,정유성 경남대학교 교육문제연구소 2002 敎育理論과 實踐 Vol.12 No.2

The Korea Research Foundation(KRF) has supported the research activity of the academic society through 'Conference Grant Program' and 'Journal Publication Subsidy program'. The purpose of this paper is to reconsider this existing KRF' support programs for the academic society by analyzing the actual condition of foreign research foundations' aid for their academic society. To find implications, this study analyzes three countries' research foundations cases: Japan Society for the Promotion of Science (JSPS), National Science Foundation (NSF), National Endowment for the Humanities (NEH), American Council of academic Societies(ACLS), and Deutsche Forschungsgemeinschaft (DFG). Data of this study collected through related research publications, internet, and interview with the persons concerned of JSPS and DFG. Based on the findings, some implications for formulating a support program for the research activity of the academic society can be suggested as follows: First, the category 'promotion of publication of scientific research results' in Grant-in-Aid for Scientific Research in JSPS was designed to provide support to the academic society of Japan. In spite of this support, the FY 2000 amount for this progam was 2.59% in JSPS' total grant. NSF, NEH, ACLS, and DFG have give no support to the academic society itself. As a general principle, a academic society of Korea like that of the United States and German is required to meet its expense through membership fee. But considering Korean academic society's financial difficulty, it is necessary for KRF to support the research activity of academic society for a time. Second, it needs to publish chargeable scientific periodicals for academic society's self-supporting. In addition, like ACLS, there needs to be formulated the system which can be supported by income from endowment, private grants, and private gifts. Third, like JSPS's grant-in-aid for 'Scientific Periodicals', it needs to bring in the principle of high competition in the allocation of KRF's existing 'Journal Publication Subsidy program. Fourth, besides the KRF's existing subsidy program for academic society, KRF needs to support academic society's educational program for student, teacher, and individual citizens in order to disseminate academic information and strengthen the scientific potential of Korea. Finally, it is necessary to formulate the system that the representatives of learned society take part in the academic policy-making body, screening committee, and selection process of KRF.

Radial ball bearing의 耐久性에 對한 力學的解析과 實驗値에 關한 高擦

丁奎祚 군산대학교 1978 群山水産專門大學 硏究報告 Vol.12 No.2

In order to detect the endurance limit according to the loads and revolutions, 5 KBC bearings and 3 NSK bearings have been applied to an apparatus made for these testings. The experimental results are as follows. a) The inner race, out- race and ball have been destroyed in the sequence. b) By comparing KBC bearings with NSK bearings, materials, heat-treatment and working accuracy were lowered but these life were greater than the rating life, 130 hours. c) KBC bearings compared with NSK bearings should be more developed in technical are.

CPLD를 이용한 3채널 PWM 신호발생기의 설계

정규홍 대진대학교 생산기술연구소 2000 생산기술연구소 논문집 Vol.3 No.-

In this research, Pulse-Width-Modulation signal generator of which carrier frequency and resolution is superior to the that of conventional peripheral functions of micro-controllers was designed with the combination of digital logic gate and 3-channels of PWM signal generators were implemented with the single Altera's EPM7128S CPLD. We established the model of digital logic circuit and verified its overall function with MAX+PLUS II software which is offered by Altera for digital logic design engineers. From the experiment of PWM signal test on the integrated hydraulic system control board, we can conclude that it works fairly good as we expected and since the speed of PLD is quite fast, there is no parallel-interfacing problem with the host micro-controller. 주요기술용어: Pulse-Width-Modulation(펄스폭 변조), CPLD(고집적 프로그래머블 논리소자)

합성수지의 접합

정규창,이철구 서울산업대학교 산업대학원 1996 大學院論文集 Vol.4 No.-

The joining of polymer materials can be mechanically fastened or adhesively bonded, but they can also be welding. Mechanical fastening is an expensive multistep operation which creates stress concentrations in the part. It provides good assurance for the quality and strength of the joint. Adhesively bonded joints have more uniform load distributions than bolted joints. Surface preparation for good wetting of the adhesive is very critical to the process. Inspection of the bond is usually required. Welding or fusion bonding is restricted to polymer materials only, and it requires heating and melting of the thermoplastic. Welded joints, like adhesively bonded joints, have more uniform load distribution than bolted joints. At present, inspection of the welded joint is usually required, however closed loop controls should soon eliminate that requirement. The theory and practice behind joint design and the use of mechanical fastening, adhesive bonding, and welding are discussed.

자동변속기의 변속품질 향상을 위한 각가속도 피이드 백 제어 알고리즘

정규홍 대진대학교 1995 大眞論叢 Vol.3 No.-

In this work, the control algorithm in automatic transmission is proposed to improve the shift quality through the feedback of turbine angular acceleration. To design the control system, dynamic behavior of the RAVIGNEAUX type planetary gear system is analyzed both in torque and in inertia phase during gear change, and the relations between output torque and turbine angular acceleration are investigated.

東方文化的再起與東方文學的相關性

丁奎福 順天鄕大學校 人文科學硏究所 1998 순천향 인문과학논총 Vol.6 No.-