항공기용 발전기 효율의 의의와 시험방법에 관한 연구

정상훈(Sang Hoon Chung),김수일(Su Il Kim),고호식(Hosik Ko),김동식(Dong Sik Kim),최정석(Jeongseok Choi),이영수(Youngsoo Lee),이준원(Joon Won Lee) 항공우주시스템공학회 2019 항공우주시스템공학회 학술대회 발표집 Vol.2019 No.11

Design and Analysis of Electromagnetic Induced Levitated-Vehicle Running Through a Tunnel

Sang Hoon Chung(정상훈),Jong Hyun Choi(최종현),Yoon Su Baek(백윤수) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

In this paper, design and analysis of a maglev vehicle that runs through a tunnel are described. Electromagnets are placed on each side of a tunnel, generating time varying magnetic field. This field then induces opposing field on surfaces of the conductor and produces levitation force and drag force on the vehicle. Net levitation force generated by opposing actuators in vertical and lateral direction can be made zero even after considering external factors like weight of the vehicle and centrifugal force. Thus, this system guarantees the stability of the vehicle in motion. At the same time, the vehicle is capable of running at a higher speed, using drag force generated from actuator on each side. The feasibility of this system was verified through finite element analysis and experiment.

HVAC System Power Consumption and Temperature Control Algorithm For OLEV<SUP>®</SUP> Application

Sang Hoon Chung(정상훈),Eun-Gyeong Shin(신은경),Jun-Ho Lee(이준호),In-Soo Suh(서인수) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

In recent years, electrical vehicles (EVs) have been in the limelight as one of the green technologies that could be the key solution to global energy depletion and green house effects. In order to overcome the most common issues when it comes to EV introduction, mostly related to batteries, KAIST introduced the new concept of electric charging technology-applied vehicle, called OLEV<SUP>®</SUP> (On-Line Electric Vehicle). The key of this technology is that it enables EV to be charged whether it is in motion or at a stop by utilizing the inductive power transmission principal. In this paper, control algorithm of HVAC system for OLEV<SUP>®</SUP> is introduced. The main purpose of this algorithm is to control the amount of power consumed by HVAC system down to 20% and 25% of the suppliable power in case of cooling and heating respectively while maintaining the desired room temperature. This particular power management is necessary because the capability of meeting the customers’ expectations on driving distance and still have other functions work as conventional cars do with the minimum amount of charging time is the key to successful EV introduction We developed a proper set of dynamic models and control algorithms for HVAC (Heating Ventilation Air-Conditioning) system linked to gether with OLEV<SUP>®</SUP> system operation. Based on the operation conditions of OLEV<SUP>®</SUP>, the advanced control algorithm is applied considering several key parameters such as power being supplied from the road, battery SOC (state of charge), power consumptions from each component of OLEV<SUP>®</SUP> and room temperature. This control algorithm aims for HVAC system to maintain the driver’s desired room temperature while consuming only 20% and 25% of the suppliable power for cooling and heating respectively.

축소-확대 유로에 적용한 횡류형 수직 풍력발전시스템의 개발

정상훈(Sang-Hoon Chung),정광섭(Kwang-Seop Chung),김철호(Chul-Ho Kim) 대한설비공학회 2011 설비공학 논문집 Vol.23 No.8

New concept of wind energy conversion system is proposed to increase the energy density at a given working space. The quality of wind for wind power generation is depend on its direction and speed. However, the quality is not good on land because wind direction is changeable all the time and the speed as well. The most popularly operated wind turbine system is an axial-flow free turbine. But its conversion efficiency is less than 30% and even less than 20% considering the operating time. In this research, a cross-flow type wind turbine system is proposed with a convergent-divergent duct system to accelerate the low speed wind at the inlet of the wind turbine. Inlet guide vane is also introduced to the wind turbine system to have continuous power generation under the change of wind direction. In here, the availability of wind energy generation is evaluated with the change of the size of the inlet guide vane and the optimum geometry of the turbine impeller blade was found for the innovative wind power generation system.

광대역 컨포멀 배열 안테나를 위한 빔 형성 연구 및 최적 소자 위치 선정

정상훈(Sang-Hoon Jung),이강인(Kang-In Lee),남상욱(Sang-Wook Nam),정용식(Young-Seek Chung),윤영중(Young-Joong Yoon),유홍균(Hong-Kyun Ryu),정현교(Hyun-Kyo Jung) 한국전자파학회 2016 한국전자파학회논문지 Vol.27 No.2

본 논문에서는 LSM(Least Squares Method)와 GA(Genetic Algorithm)를 이용한 광대역 컨포멀 배열 안테나의 최적 빔형성을 제안하였다. LSM을 적용하여 컨포멀 배열 안테나의 빔 패턴을 선형 배열 안테나의 빔 패턴으로 근사시키는 가중치들을 구하였다. 그리고 GA를 이용하여 광대역에서 최적의 빔 패턴을 형성하는 컨포멀 배열 안테나의 최적 위치들을 구하였다. 제안된 방법을 검증하기 위해 Bezier 플랫폼 배열 안테나에 적용시켜 보았다. This paper proposes an optimum beam forming of conformal array antenna by using LSM(Least Squares Method) and GA(Genetic Algorithm). The weights which approximate conformal array antenna beam pattern to linear array antenna beam pattern have been evaluated by applying LSM. Also, the optimum locations of conformal array antenna which form wideband optimum beam pattern have been obtained by using GA. The proposed method is applied to a problem of Bezier platform array antenna for a verification purpose.

지리산 서부권역 천연림의 산림피복형별 생태적 해석 및 종다양성과 지형조건 특성에 근거한 천이경향 추정

정상훈 ( Sang Hoon Chung ),황광모 ( Kwang Mo Hwang ),김지홍 ( Ji Hong Kim ) 한국산림과학회 2014 한국산림과학회지 Vol.103 No.4

The purpose of this study was to interpret ecological characteristics and to estimate successional trendfor seven classified forest cover types (Quercus mongolica pure forest, Q. mongolica-Q. serrata forest, Mixedmesophytic forest, Abies koreana-Q. mongolica forest, Fraxinus mandshurica forest, Q. serrata forest, andCarpinus laxiflora forest) in the natural forest of Western Jirisan. Q. mongolica pure forest and A. koreana-Q. mongolica forest which were distributed in a high-altitude ridge had the lowest species diversity index. On theother hand, mixed mesophytic forest and F. mandshurica forest which were mainly distributed in the valley hadhigher index. Based on characteristics of species diversity and topographic conditions, successional trends forforest cover types were estimated as follows; 1) Q. mongolica pure forest and A. koreana-Q. mongolica forestwould be changed toward Q. mongolica-A. koreana forest. 2) Q. mongolica-Q. serrata forest, distributed betweenridge and mid-slope, would be changed toward Q. mongolica-C. laxiflora-C. cordata forest. 3) Q. serrata forest,distributed in mid-slope, would be changed toward Q. serrata-Q. mongolica-C. laxiflora forest. 4) Mixed mesophyticforest, F. mandshurica forest and C. laxiflora forest, distributed in valley, would maintain the current conditionin terms of species composition.

속리산 천왕봉 일대의 산림형 분류와 생태적 특성

정상훈 ( Sang Hoon Chung ),황광모 ( Kwang Mo Hwang ),성주한 ( Joo Han Sung ),김지홍 ( Ji Hong Kim ) 한국산림과학회 2015 한국산림과학회지 Vol.104 No.3

We classified the forest type and figured out the ecological characteristics for each of the types in order to provide the basic informations for being induced ecologically efficient forest practice plan by vegetation units in the natural forest of Songnisan. We established the 250 sample points and collected the vegetation data of vertical distribution for each sample. A variety of multivariate statistical methods were applied to classify the forest types. The species diversity index were analyzed to estimate the stability and maturity for forest vegetation in each the type. The types were divided from two to ten clusters by cluster analysis. The appropriate number of clusters was estimated five clusters by indicator species analysis. It was verified through the multiple discriminant analysis that the estimated number of clusters had been suitable. Based on the species composition for each the type, this study site was classified into five forest types: 1) Quercus serrata and 2) mixed mesophytic forest in the valley area, 3) Q. mongolica forest in the main ridge, 4) Pinus densiflora forest in the sub-ridge extending from the main, and 5) Q. variabilis-P. densiflora forest between the sub-ridge and valley. The species diversity index of the pine forest that had been a simple species composition was the lowest while that of the mixed mesophytic forest of which the composition had been diverse was the highest. As the forest vegetation was more varied, the index showed a tendency to increase.

공간회귀모델을 적용한 지역주민 연령과 도시공간구조 패턴 상관성 연구 : 아산시와 천안시 주민의 평균연령을 중심으로

정상훈(Jeong, Sang Hoon),이상조(Lee, Sang Jo),신상화(Shin, Sang Hwa),정재우(Chung, Jae Woo) 한국주거환경학회 2021 주거환경(한국주거환경학회논문집) Vol.19 No.3

In this study, the correlation between the average age of residents and the characteristics of urban spatial structure such as demographic change, number of wholesale and retail workers, number of manufacturing workers, ratio of small houses, ratio of old buildings, and area of development projects in Asan and Cheonan was investigated. For the purpose, spatial autocorrelation and spatial lag model were applied. The increase in the area of various development projects such as industrial complex and housing estate construction had the effect of lowering the average age of the local population. The increase in the ratio of old buildings and small houses has a positive(+) and negative(-) effect on average age, respectively. The average age of residents is high in areas with a high proportion of manufacturing workers and wholesale and retail workers. The average age of the residents is decreasing in regions where the population is increasing. The average age of a local resident was found to be highly spatially dependent on the surrounding area. The value of the spatial lag variable(Rho), which shows the influence of surrounding regions on the average age of one region, was 0.471, statistically confirming that the average age was spatially clustered.

A study on Loss Evaluation Technology of High Efficiency Mold Transformers using Electromagnetic Field Simulation

Sang Hoon Chung(정상훈),Kon Lee(이곤),Myung Jun Choi(최명준) 대한전기학회 2015 대한전기학회 학술대회 논문집 Vol.2015 No.7

향로봉 일대 천연림의 산림 피복형 분류

정상훈 ( Sang Hoon Chung ),황광모 ( Kwang Mo Hwang ),강성기 ( Sung Kee Kang ),임선미 ( Seon Mi Lim ),김지홍 ( Ji Hong Kim ) 한국임학회 2014 산림과학 공동학술대회 논문집 Vol.2014 No.-

향로봉 일대는 한국전쟁 당시 격전지로서 식생의 파괴가 매우 심했던 곳이지만, 휴전 후 반세기 동안 인위적인 교란 없이 자연적인 천이과정을 거쳐 현재의 산림상태를 유지하고 있는 독특한 산림구조를 가지고 있다. 본 연구는 인위적 교란을 받은 산림의 피복유형을 분류하고, 피복유형 분류에 가장 큰 영향을 끼치는 수종을 알아보는 것에 그 목적이 있다. 점표본법으로 수집된 식생자료를 바탕으로 계층적 군집분석, 지표종분석, 다중판별분석 등 다변량 통계 분석법을 이용하여 식생자료를 분석하였다. 연구대상지를 2~10개의 클러스터로 분류하였고, 지표종분석을 통해 연구대상지의 적정클러스터 수는 5개인 것으로 파악되었다. 이를 통계적으로 검증하기 위해 다중판별분석을 실시하였고, 91.3%가 정확하게 분류되어, 연구대상지 산림 피복형의 개수는 5개가 적당한 것으로 나타났다. 각 클러스터 상층의 우점수종 비율에 따라 신갈나무순림, 신갈나무림, 신갈나무-잣나무림, 신갈나무-피나무림, 신갈나무-음나무-거제수나무림으로 산림 피복형을 명명하였으며, 신갈나무의 점유비율이 산림 피복형 명명에 큰 영향을 미치는 것으로 나타났다. The Hyangnobong area was a battlefield during the Korean War and where the forest vegetation had been severely destroyed. However, this forest has a distinctive forest structure that has been maintaining a current forest condition following the natural succession process for a half century after the armistice agreement. This study was conducted to classify the forest cover types formerly disturbed forest and recognize the species which has a strong influence on classifying forest cover types. The collected vegetation data by point quarter sampling method were analyzed using the multivariate statistical analysis such as hierarchical cluster analysis (HCA), indicator species analysis (ISA), and multiple discriminant analysis (MDA). The study area was classified into 2 to 10 clusters and ISA indicated that the optimal number of clusters was five. MDA was taken to test the number of cluster that classified with HCA and ISA. The five clusters were most appropriate to the overall successful classification with the 91.3 % of probability. The classified forest cover types were named by the ratio of the dominant species in the upper layer of each cluster; Quercus mongolica pure forest, Q. mongolica forest, Q. mongolica-Pinus koraiensis, Q. mongolica-Tilia amunensis, and Q. mongolica-Kalopanax septemlobus-Betula costata. The compositional ratio of Q. mongolica had an important effect to designate forest cover types.