환경비용 및 운용방식에 따른 MicroGrid 경제성분석

박중성(Jung-Seong Park),신혜경(Hye-Gyeong Sin),왕인수(In-Su Wang),홍정기(Jeong-Gi Hong) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.7(초록집)

한반도 동해안 석호의 관속식물상

김중현,김선유,홍정기,남기흠,안지홍,이병윤,김진석,Kim, Jung-Hyun,Kim, Sun-Yu,Hong, Jeong-Ki,Nam, Gi-Heum,An, Ji-Hong,Lee, Byoung Yoon,Kim, Jin-Seok 한국식물분류학회 2017 식물 분류학회지 Vol.47 No.1

동해안 석호는 해수와 담수가 섞인 독특한 형태의 기수호이며, 수변식생이 발달되어 생물다양성이 풍부한 지역이다. 본 연구는 국내에 분포하는 17개소의 석호에 대한 식물상과 식물 종조성 등의 조사를 통하여 석호 식생에 대한 안정적인 보전계획 수립을 위한 기초자료를 제시하고자 한다. 17개소의 석호에 대한 식물상 조사결과, 관속식물은 118과 378속 655종 13아종 46변종 6교잡종, 총 720분류군이 확인되었다. 이중에서 한반도 고유종이 11분류군, 멸종우려 식물이 18분류군, 식물구계학적 특정식물인 IV-V등급 식물이 23분류 군이었다. 남방계식물은 4분류군, 북방계식물은 8분류군으로 조사되었고, 특히 남한 내 희귀식물인 갯활량나물(Thermopsis lupinoides), 기름당귀(Ligusticum hultenii), 벼룩아재비(Mitrasacme alsinoides), 통발(Utricularia australis), 검정납작골풀(Juncus fauriei), 새방울사초(Carex vesicaria), 천도미꾸리광이(Puccinellia kurilensis) 등이 동해안 석호에서 생육하고 있었다. 외래식물은 96분류군이 발견되었다. 한반도 석호는 식물다양성이 풍부하고, 희귀식물 및 식물지리학적 중요한 식물이 관찰된다. 석호의 효과적인 관리와 생물다양성 보전을 위해 체계적인 사항들이 논의되었다. Eastern coastal lagoons are a particular type of estuarine systems where seawater mixes with fresh water from their catchments. With the development of aquatic vegetation, this area shows high level of biodiversity. The purpose of this study is to produce a strategy for the comprehensive conservation of the vegetation of coastal lagoons through studies of the floristics and plant species compositions in 17 eastern coastal lagoons in Korea. Vascular plants were collected 109 times, from June of 2010 to November of 2014. The results showed that there were 720 taxa in total, including 118 families, 378 genera, 655 species, 13 subspecies, 46 varieties, and 6 hybrids. Korean endemic species numbered 11 taxa, and vascular plants listed in the red list according to the International Union for Conservation of Nature (IUCN) numbered 18 taxa. Indicator species of fourth (IV) and fifth (V) degree, as specified by floristic subregions, numbered 23 taxa. Among the species investigated in this survey, there were 4 taxa of plants of southern origin and 8 taxa of plants of northern originin the Korean peninsula. Several rare plants, Thermopsis lupinoides, Ligusticum hultenii, Mitrasacme alsinoides, Utricularia australis, Juncus fauriei, Carex vesicaria, and Puccinellia kurilensis, were distributed in eastern coastal lagoons. In all, 96 alien plants were recorded in the investigated area. The coastal lagoons on the eastern coast of Korea showed high plant diversity with many rare plants and phytogeographically important plants. Conservation strategies to ensure biodiversity and effective management of coastal lagoons are discussed in detail.

유도 전동기의 고정자 권선 사고에 대한 모델링 방법

남순열(Soon-Ryul Nam),홍정기(Jung-Gi Hong),박종근(Jong-Keun Park) 대한전기학회 2003 대한전기학회 학술대회 논문집 Vol.2003 No.11

중량 부하에 따른 8주간의 플라이오메트릭스 트레이닝이일반인의 스쿼트점프에 미치는 영향

명태순 ( Tae Soon Myoung ),홍정기 ( Ki Kwang Lee ),이기광 ( Jung Gi Hong ),공세진 ( Se Jin Kong ),이정호 ( Jung Ho Lee ),김진현 ( Jin Hyun Kim ) 한국스포츠정책과학원(구 한국스포츠개발원) 2015 체육과학연구 Vol.26 No.1

The purpose of this study was to find which percentage of 1RM for squat to improve the result of squat jump most effectively after plyometric training with different percentage of 1RM for squat. 24 men in their twenties were measured 1RM for squat and separated in 4 groups by 6 participants. Group A, B, C, and D used 0, 15, 30, and 45% of 1RM, respectively in the plyometric training. All groups had 1 hour training 3 days per week for 8 weeks(24 sessions). This study designed to increase the number of sets of exercises gradually. In week 1 and 2, participants trained 1 set of plyometrics with no load. The number of sets increased 2 to 4 in the week 3-4 to 7-8. The jump height(cm) and vertical impulse(%BW) of squat jump before and after plyometric training were measured by 3D motion capture system and force plate. All 4 groups showed the improvement of squat jump height and vertical impulse, but specially group B was most improved(p<0.5). 본 연구에서는 20대 일반 성인남성이 중량을 이용한 플라이오메트릭스 트레이닝을 하였을 때 가장 효과적으로 스쿼트 점프를 향상시킬 수 있도록 1RM의 적정한 부하를 찾고자 하였다. 대상자는 건강한 성인남성 24명으로 스쿼트의 1RM을 측정하여 1RM에 대한 4개의 트레이닝집단으로 각각 6명씩 무선배정 하였다. 트레이닝집단은 1RM의 0%부하(A집단), 15%부하(B집단), 30%부하(C집단), 45%부하(D집단)으로 구분하였고, 8주 동안 플라이오메트릭스 트레이닝(주 3회 1시간)을 실시하였다. 본 트레이닝 프로그램은 1~2주, 3~4주, 5~6주, 7~8주로 총 4개의 트레이닝 프로그램으로 2세트에서 4세트로 점증적으로 수행 세트 수를 증가시켰다. 1주~2주 트레이닝은 모든 집단이 중량부하를 주지않고 맨몸으로 운동을 진행하였고, 3주~8주까지는 중량부하를 주어서 운동을 실시하였다. 영상분석 자료와 지면반력 자료를 이용하여 트레이닝 전후에 스쿼트 점프 시 발생하는 점프높이(cm), 충격량(%BW)을 산출하였다. 결론으로 네 집단모두 점프높이와 충격량이 향상되었지만, 특히 B집단(15%)에서의 점프높이와 충격량이 가장 많이 향상되었다(p<0.5).

전력 시스템 자동화를 위한 디지털 전력장치의 구현

오재훈(Jae-Hoon Oh),홍정기(Jung-Gi Hong) 전력전자학회 2004 전력전자학술대회 논문집 Vol.- No.-

Lately, the Intelligent Electronic Device(IED) and the Power System Automation make subjects of discussions and studies. The IED uses microprocessors to practice a lot of functions. In the analog time, an equipment practices only one or two functions. But according to the development of microprocessor and digital technology, it can be implemented by using those kinds of state of the art technology and its function is become more and more powerful. Also, the proliferation of IED makes possible to construct power system automation. An automation of power system make more convenient, safe, and accurate power system. In this paper, a digital protective relay which is a kind of IED and the power automation system are briefly discussed with development and application cases.

토픽 모델링을 활용한 부동산 대책 및 사회적 이슈 분석

윤성진(Yun, Sungjin),이관용(Lee, Kwanyong),홍정기(Hong, Jung-Gi) 한국부동산정책학회 2021 不動産政策硏究 Vol.22 No.1

This article synthesizes the numerous real estate measures taken by the Moon Jae-in administration of the Republic of Korea and the complex controversy surrounding them. The Korean government uses several policy measures in response to soaring housing prices, and these measures have been conducted under social context and created new disputes. Therefore, analyzing the trends in policy changes and social discussion behind them is necessary. In this context, we analyzed online news articles data through topic modeling, which is a text mining. Results show high interest in comprehensive measures, including loan regulation and tax policy, such as September 13, December 16, and June 17 measures. Although one measure included a number of policy points, the media has focused on specific issues such as “comprehensive real estate tax” in September 13 measure and “gap investment regulation” in June 17 measure. The topic modeling analysis identified 17 detailed topics under five categories: loan regulation, tax policy, public housing supply, private housing supply, and market response to measures. Moreover, some social debates not only show the previous conditions but also provide implications for future housing policy, such as preserving greenbelt zones, realization of official housing price for tax, and the balloon effect of the housing market.

Rasch 모형을 활용한 U-19 축구 국가대표팀 선수들의 기능적 움직임 능력 검증

최용석 ( Yong Suk Choi ),최수지 ( Su Ji Choi ),강윤중 ( Yun Jung Kang ),장동규 ( Dong Kyu Jang ),정다움 ( Da Um Jung ),박미나 ( Mi Na Park ),강성우 ( Sung Woo Kang ),전지현 ( Ji Hyun Chun ),이미영 ( Mi Young Lee ),홍정기 ( Jung Gi 한국스포츠정책과학원(구 한국스포츠개발원) 2015 체육과학연구 Vol.26 No.4

본 연구는 기능적 움직임 검사(Functional Movement Screen: FMS)의 결과를 통해 U-19 축구선수 집단에 적용된 FMS 측정항목들의 적합성과 난이도를 분석하여 U-19 축구선수들의 기능적 움직임 특성 및 능력을 파악하고자 하였다. 파주 NFC U-19 축구 국가대표팀 선수들 30명(19.3±0.66세)의 FMS 7개 항목(Deep Squat: DS, Hurdle Step: HS, In-line Lunge: IL, Shoulder Mobility: SM, Active Straight Leg Raise: ASLR, Trunk Stability Push-Up: TSPU & Rotary Stability: RS)을 측정하였다. 그 결과를 바탕으로 Rasch 모형을 사용하여 선수들에 대한 측정항목의 적합성(goodness-of-fit)과 난이도(item difficulty)를 분석하였다. FMS측정 결과, 총 점수 평균은 10.02±1.79점이였으며, HS, SM, TSPU를 제외한 DS, RS, IL, ASLR가 적합한 측정항목으로 나타났다(0.5< x <1.5). 또한, 적합한 측정항목인 DS, IL, ASLR, RS의 난이도는 2.08, .26, -3.16, .83(logit)으로 나타났으며, 순서대로 난이도가 높은 것으로 밝혀졌다. 따라서 본 연구는 U-19 축구선수들의 기능적 움직임의 수준이 성인 선수들 보다 낮으며, FMS 측정항목들이 종목의 특성과 선수들의 연령에 따라 다른 결과를 나타낼 수 있음을 제시하고 있다. The primary purpose of the study was to identify the characteristics of Korean national youth soccer players’ functional movements. The secondary purpose was to examine whether certain tests of Functional Movement Screen (FMS) meaningfully achieve goodness-of-fit for the soccer-specific movements. Korean national youth soccer players (30 male players, 18.37 ± 0.67 yrs, 178.7±7.09 cm, 70.2±6.46 kg), performed FMS tests [deep squat (DS), hurdle step (HS), in-line lunge (IL), shoulder mobility (SM), active straight leg raise (ASLR), trunk stability push-up (TSP), and rotary stability (RS)]. The mean (±SD) FMS composite score and each test score were calculated. Rasch analysis, which was used to determine the goodness-of-fit for the tests, was applied to examine the item difficulty of the FMS tests. The mean FMS composite score was 10.2± 1.79; the mean DS, HS, IL, SM, ASLR, TSP, and RS score were 1.13±0.35, 1.27±0.45, 1.4±0.56, 1.6±0.77, 2.07±0.69, 1.43±0.82, and 1.3±0.47 respectively. According to the results of Rasch analysis, 4 tests (DS, IL, ASLR, and RS) were shown to be within the acceptable range (infit & outfit > 0.5 ~ < 1.5). The other 3 tests (HS, SM, and TSP) were shown to be out of acceptable range. The additional analysis revealed the DS (logit = 2.08) as the most difficult test and ASLR (logit = -3.16) the least. The results of the study showed that the players’ FMS composite score was lower (< 14) than the cut-off points used by previous studies for different athletes. The further study is warranted to examine the relationships between the scores of the tests appeared to be soccer-specific in the present study and the level of performance variables.

가스 터빈 블레이드의 립 냉각과 딤플-립 복합 냉각 기법 비교연구

최용덕(Yong Duck Choi),이용진(Yong Jin Lee),홍정기(Jung Gi Hong),김진곤(Jin Kon Kim),곽재수(Jae Su Kwak) 한국유체기계학회 2009 유체기계 연구개발 발표회 논문집 Vol.2009 No.-

Detailed distributions of the heat transfer coefficients in a channel with angled rib or both rib and dimple were measured by the transient liquid crystal technique. The channel aspect ratio, rib height, rip pitch, rib angle were 2, 6 ㎜, 60 ㎜, and 60 degree, respectively. The diameters and center-to-center distance of the dimple were 6 ㎜ and 7.2 ㎜, respectively. Results show that the distribution of heat transfer coefficient was asymmetric due to the secondary flow induced by the angled rib. Also, dimples fabricated between the ribs increased the heat coefficient. Thus, the compound cooling technique with angled rib arid dimple can be improve the heat transfer performance of a gas turbine blade.

IEC61400-25 국제 표준 프로토콜을 적용한 풍력 발전 모니터링 시스템 개발 사례

이덕수(Duck-Su Lee),이준철(Jun-Chul Lee),홍정기(Jung-Gi Hong) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.7

웹 기반의 분산제어 시스템에 관한 연구

김민석(Min-Seok Kim),김한승(Han-Sung Kim),홍정기(Jung-Gi Hong) 대한전기학회 2005 대한전기학회 학술대회 논문집 Vol.2005 No.7