시스템다이내믹스 시뮬레이션을 이용한 주택 수요 조절 정책의 타당성 평가

황성주,박문서,이현수,김현수,Hwang, Sung-Joo,Park, Moon-Seo,Lee, Hyun-Soo,Kim, Hyun-Soo 한국건설관리학회 2010 한국건설관리학회 논문집 Vol.11 No.5

Recent periodical boom and burst of house price have made mortgage lending issues become the main public interest in Korean real estate market. However, because mortgage-lending issues had not been discussed until then, housing market forecasting associated with mortgage lending has been difficult while using an empirical approach. Thus, comprehensive and systematic approach is required as well as validity of mortgage lending policies should be evaluated. In this regard, this research conducts a sensitivity analysis to validate the proposed policies and estimates the effects of current policies on LTV and DTI ratios with a comparison of another policies scenario. A causal loop and sensitivity analysis using system dynamics confirmed that LTV and DTI regulation is strong clout to housing market. However, to prevent transfer of potential mortgage borrowers to nonmonetary institutions, regulations in loans of nonmonetary institutions should be practiced in accompaniment with regulations of primary lending agencies. 최근 몇 년간 주택가격의 주기적 변동에 대한 대응으로 정부는 주택담보대출 비율 (LTV) 및 총 부채상환비율 (DTI) 등 주택 담보대출 비율 조절 정책을 지속적으로 시행하고 있다. 그러나 한국 주택시장에서는 최근에 들어서야 주택담보대출을 통한 주택수요 조절 개념이 정착되었기 때문에 경험적 방법의 접근으로는 주택담보대출 정책 타당성을 평가하는데 한계가 있다. 따라서 다양한 시각 및 시스템적 논리로 접근하는 포괄적이고 동태적인 분석 방법론이 요구된다. 본 연구는 시스템 다이내믹스 (System Dynamics)의 시스템적 사고 및 시뮬레이션 모형을 통한 민감도 분석을 통해 주택 담보대출 정책의 주택 수요 및 가격 조절 기능에 대한 타당성을 평가한다. 분석 결과 주택담보대출 관련 정책은 경기 침체시 있는 것으로 분석된다. 그러나 주택담보대출 규제로 인해 1차 대출기관의 잠재 수요가 제 2 금융권 시장으로 이동할 경우 주택수요 조절을 위한 정책 의도가 상쇄되는 것을 확인할 수 있고 이에 따라 제 2 금융권 대출에 대한 정책 병행의 필요성을 도출 할 수 있다.

BIM 기반의 설계단계 원가예측 시계열모델 -자재가격을 중심으로-

황성주,박문서,이현수,김현수,Hwang, Sung-Joo,Park, Moon-Seo,Lee, Hyun-Soo,Kim, Hyun-Soo 한국건설관리학회 2011 한국건설관리학회 논문집 Vol.12 No.2

최근 도심지 고밀화에 따른 공간의 효율적 이용이 요구됨에 따라 대규모의 고층 사무공간이 증가하고 있으며, 이와 함께 주거, 상업, 문화 등 다양한 기능을 밀접하게 연관시킨 고층 복합시설도 점차 늘어가고 있다. 이러한 대형 건설, 프로젝트는 긴 공사기간이 소요되어 공사비 예측이 쉽지 않으며, 막대한 비용이 투입되기 때문에 비용 예측의 중요성이 더욱 증대되고 있다. 이러한 상황에서 최근 극심한 경제변화에 따른 건설자재가격의 변동은 자재비를 포함한 공사비 예측을 어렵게 만드는 주요 원인이다. 따라서 본 연구는 건설자재단가 시계열자료를 활용, 미래의 자재단가 예측을 위한 시계열모델을 구축하고 복잡한 모델 프로세스를 간소화하는 자재별 최적 예측모델 도출시스템을 구축한다. 또한 Building Information Modeling(BIM)의 접근을 통해 자재의 투입시기 및 투입물량을 분석, 시계열모델을 통해 예측한 자재단가 예측 값과 조합함으로써 총 자재비를 포함하는 BIM기반 공사원가 예측 시계열모델을 제시한다. 본 연구는 시계열모델의 하나인 Autoregressive Integrated Moving Average(ARIMA)모델에 대한 예측력 비교를 통해 자재단가 예측을 위한 적합모델을 도출하였다. BIM기반의 원가예측 시계열모델은 자재의 투입시기별 자재단가 변동치를 예측함으로써 급변하는 경제 환경 변화에 대처할 수 있는 도구가 될 것이다. High-rise buildings have recently increased over the residential, commercial and office facilities, thus an understanding of construction cost for high-rise building projects has been a fundamental issue due to enormous construction cost as well as unpredictable market conditions and fluctuations in the rate of inflation by long-term construction periods of high-rise projects. Especially, recent violent fluctuations of construction material prices add to problems in construction cost forecasting. This research, therefore, develops a time-series model with the Box-Jenkins methodologies and material prices time-series data in Korea in order to forecast future trends of unit prices of required materials. BIM (Building Information Modeling) approaches are also used to analyze injection time of construction resources and to conduct quantity takeoff so that total material price can be forecasted. Comparative analysis of Predictability of tentative ARIMA (Autoregressive Integrated Moving Average) models was conducted to determine optimal time-series model for forecasting future price trends. Proposed BIM based time series forecasting model can help to deal with sudden changes in economic conditions by estimating future material prices.

산소중독에 대한 MALTOL의 보호효과에 관한 실험적 연구

황성주,조수헌,윤덕로,Hwang, Sung-Joo,Cho, Soo-Hon,Yon, Dork-Ro 대한예방의학회 1993 Journal of Preventive Medicine and Public Health Vol.26 No.4

Since the widespread application of hyperbaric oxygenation in clinical medicine, the problems of oxygen toxicity have been attracting a deep interest from the researchers on hyperbaric medicine as a practical issue. Among extensive research trials, the study on the protective agents oxygen toxicity occupied one of the most challenging field. As the mechanisms of oxygen toxicity, the role of the oxygen free radicals produced by peroxidation process are strongly accepted by the leading researchers on oxygen toxicity, the probable protective effects of antioxidant against oxygen toxicity are sustaining a sufficient rational. Maltol ($2-methyl-3-hydroxy-{\gamma}-pyrone$) which is known to be a component of Korean red ginseng has been reporting to have an antioxidant action. But, further study is needed to provide definite evidence for this compound to be an antioxidant, since the action was based on the results which were obtained under in vitro experiment. In this study, the author attempted to evaluate the effect of maltol as protective agent against oxygen toxicity through the observation of death rate, convulsion rate, time to convulsion and microscopic pathological changes in some organs of experimental rats exposed to various conditions. The findings observed are as follows : 1) The death rate, convulsion rate, time to convulsion, lung/weight ratio and microscopic pathological finding of lung were identified as reliable objective and quantitative indices for oxygen toxicity. 2) Maltol showed excellent protective effect against pulmonary oxygen toxicity as an antioxidant.

오메프라졸복합체 함유 직장좌제의 특성비교

황성주,박성배,이계주,Hwang, Sung-Joo,Park, Sung-Bae,Rhee, Gye-Ju 한국약제학회 1995 Journal of Pharmaceutical Investigation Vol.25 No.3

Omeprazole(OMP) complexes such as inclusion complexes of OMP with $hydroxypropyl-{\beta}-cyclodextrin$(HPCD) and ${\beta}-cyclodextrin({\beta}-CD)$, OMP-cholestyramine(CHL) and OMP-ethylenediamine(OMP-ED) were prepared, respectively. The partition coefficients in Witepsol H-15 /pH 7.4 phosphate buffer solution of OMP complexes$(OMP-HPCD;\;3.69{\pm}0.26,\;OMP-{\beta}-CD;\;4.08{\pm}0.21,\;OMP-CHL;\;4.36{\pm}0.25\;and\;omeprazole\;sodium(OMP-Na);\;3.64{\pm}0.37)$ were higher than that of OMP $(2.66{\pm}0.47)$. OMP was not completely dissolved until even 3 hrs, but all the OMP complexes studied were released about 100% in 20 min. The rectal suppositories containing OMP or each above OMP complex were prepared using Witepsol H-15 base, and their dissolution and stability were examined, and pharmacokinetic study were investigated after their rectal administrations to the rabbits. While the suppository containing OMP was released only less than 60% in 150 min, $OMP-{\beta}-CD$, OMP-CHL, OMP-Na and OMP-ED suppositories were all released about 65% in 20 min. Especially, OMP-HPCD suppository released OMP about 70% in 10 min. All the additives such as sodium laurylsulfate, eglumine, arginine and PVP increased drug release from OMP-HPCD suppository to some extent. The decomposition rate constants of OMP in the suppositories were $9.117{\times}10^{-3}\;day^{-l}$ for OMP suppository, $2.121{\times}10^{-2}$ for OMP-HPCD, $1.607{\times}10^{-2}$ for $OMP-{\beta}-CD$, $9.26{\times}10^{-3}$ for OMP-Na, $6.769{\times}10^{-3}$ for OMP-CHL and $5.58{\times}10^{-3}\;day^{-l}$ for OMP-ED suppository, respectively. Additives such as arginine, eglumine and ED had some stabilizing effect for OMP-HPCD, OMP-CHL and OMP-Na suppositories, respectively. After 6 month-storage at $30^{\circ}C$, 75% RH, OMP-CHL suppository was most stable. The values of Tmax for OMP-HPCD and OMP-Na suppositories were $11.7{\pm}2.36\;and\;11.4{\pm}2.56\;min$, respectively. The values of Cmax for OMP-HPCD and OMP-CHL suppository were $2.31\;{\mu}g/ml\;(p<0.01)\;and\;1.89\;{\mu}g/ml\;p<0.01)$, respectively. The values of AUC for OMP and $OMP-{\beta}-CD$ suppository were $61.9{\pm}25.79\;and\;68.6{\pm}29.48\;{\mu}g\;{\cdot}\;min/ml$, and the corresponding values for OMP-HPCD and OMP-CHL were $106.1{\pm}43.16\;(p<0.05)\;and\;127.3{\pm}42.52\;{\mu}g\;{\cdot}\;min/ml(p<0.01)$, respectively. The above results indicate the OMP-HPCD and OMP-CHL suppositories have the excellent bioavailabilties in vivo study.

주택공급전략 타당성 검토를 위한 시스템다내믹스 모델 개발

황성주,박문서,이현수,김현수,Hwang, Sung-Joo,Park, Moon-Seo,Lee, Hyun-Soo,Kim, Hyun-Soo 한국건설관리학회 2011 한국건설관리학회 논문집 Vol.12 No.5

최근 한국 주택시장의 혼재하고 있는 문제점으로 인해 공급기반 강화 전략이 중요한 화두가 되고 있다. 특히, 2008년 이후 금융시장 불안으로 인한 주택시장의 침체로 미분양주택 해소 및 서민주거안정을 위한 정책이 요구되고 있다. 그러나 이들은 주택공급조절과 주택공급확대라는 서로 상반된 목표를 갖고 있기 때문에 정책결정에 어려움을 발생시킨다. 따라서 본 연구는 미분양해소 및 서민주거확대를 위한 주택정책 적용 시 주택시장을 구성하는 다양한 변수 간 관계들의 구조적 변화를 파악함으로써 정책 실효성을 분석하는 시스템다이내믹스 모델을 개발한다. 개발된 모텔에 다양한 정책 시나리오를 적용함으로써 가능한 정책대안들을 평가하고, 문제해결을 위한 정책을 제안한다. 연구 결과, 민간을 배제한 공공 주도의 공급정책 및 미분양주택 해결을 위한 민간 주택건설 규제는 건설시장의 자율조절기능을 위축시키는 요소로 작용할 수 있다. 따라서 민간 주택건설의 자율적 조절기능을 지원하는 정책을 마련해야 민간 주택시장의 공급체계 안정화 및 수요-공급 조절기능의 정상화를 이룰 수 있다. Establishing housing supply strategies in Korean housing market is a crucial issue due to contradictory but concurrent two problems in market; one is the unstable working-class residential and the other is the high vacancy rate by the low-level of sales rate. Although government has been continuously implementing various supply policies in an attempt to evenly distribute houses as well as to keep supply and demand in balance, it is difficult to satisfy all of stakeholders, such as housing consumers, housing owners and housing suppliers. This paper, therefore, applies a system dynamics methodology and offers a dynamic and integrated model encompassing for-profit behaviors of each market participants. The proposed model simulates the future trends of house prices, the balances between supply and demand, construction companies earnings and vacancy rate when applying various housing supply scenarios. From the simulation result, recent governmental small-size rental housing supplies in bulks should utilize private construction companies to stabilize housing distribution rate and private supply system as well as the supply and demand are well balanced.

주택담보대출 규제 완화에 따른 부동산시장 영향 분석: 시스템다이내믹스 모형 개발

황성주,박문서,이현수,윤유상,Hwang, Sung-Joo,Park, Moon-Seo,Lee, Hyun-Soo,Yoon, You-Sang 한국건설관리학회 2010 한국건설관리학회 논문집 Vol.11 No.1

최근, 미국에서 발생한 주택담보대출시장 비우량대출 부실로 인한 세계 금융위기에 따라, 우리나라 주택시장 또한 침체를 겪고 있다. 이에 대한 대응으로 정부는 주택 수요 활성화를 위한 다양한 규제 완화 정책을 시도 하고 있다. 특히, 주택담보대출비율(LTV) 및 총부채상환비율(DTI) 와 같은 주택담보대출 기준의 완화를 통해 주택수요 및 주택 거래의 활성화를 기대하고 있으며, 2차 주택담보대출시장을 활성화하여 주택 수요의 지속적인 발생을 유도하고자 한다. 그러나 이러한 정책은 비우량 대출 부실로 시작된 세계 금융위기에 역행하는 시도가 될 수 있다. 이러한 상황에서, 시장에 대한 예측은 대부분 단편적인 시각으로 이루어지고 있어, 향후 주택시장의 변화에 대한 종합적이고 체계적인 예측 방법론에 대한 필요성이 대두되고 있다. 따라서 본 연구는, 주택시장 및 주택담보대출시장을 구성하는 기본 요소를 바탕으로 통합된 관점의 주택시장 시스템다이내믹스 연구 모형을 작성한다. 또한, 연구 모형을 통해 정부의 주택담보대출 규제완화가 시장 참여자에 미치는 영향을 알아본다. 이는 수요 자극을 통해 침체된 주택시장의 주택거래 활성화 효과를 기대하고 있으나, 제 2 주택담보대출 시장의 형성 및 부실 파생상품 생성 가능성을 높일 위험을 갖고 있다. The Korean real estate market currently is experiencing a slowdown due to the global economic crisis which has resulted from subprime mortgage lending practices. In response, the Korean government has enforced various policies, based on intend to deregulate real estate speculation, such as increasing the Loan to value ratio (LTV) in order to stimulate housing supply, demand and accompanying housing transactions. However, these policies have appeared to result in deep confusion in the Korean housing market. Furthermore, analyses for housing market forecasting particularly those which examine the impact of the international financial crisis on the Korean real estate market have been partial and fragmentary. Therefore, a comprehensive and systematical approach is required to analyze the real estate financial market and the causal nexus between market determining factors. Thus, with an integrated perspective and applying a system dynamics methodology, this paper proposes Korean Real Estate and Mortgage Market dynamics models based on the fundamental principles of housing markets, which are determined by supply and demand. As well, the potential effects of the Korean government's deregulation policies are considered by focusing on the main factor of these policies: the mortgage loan.

초음파가 Methyl nicotinate 경피흡수에 미치는 영향

황성주,정상립,김도원,전재복 ( Sung Joo Hwang,Sang Lip Chung,Do Won Kim,Jae Bok Jun ) 대한피부과학회 1997 대한피부과학회지 Vol.35 No.5

Background: The mechanism of enhancing effect of ultrasound on the percutaneous absorption of a drug is unclear. But thermal, chemical and mechanical effects are assumed to play a role in enhancing transdermal drug delivery. Objective : The aim of this study was to determine if ultrasound enhances percutaneous absorption of methyl nicotinate(MN) without raising the skins surface temperature. Methods . Treatment consisted of the application of ultrasound massage(1.0 MHz, 1.0 watt/cm, continuous output) or placebo massage(0 MHz) for 3 min to the forearms of the volunteers, followed by a standardized application of MN at intervals of 15 sec and 10 min postmassage. Percutaneous absorption of MN was monitored using laser doppler flowmetry. Results : 1. Data from the ultrasound treated sites after 15 sec showed significant decrease(p < 0.05, paired t-test) in the T(time between MN application and its initial response), T(time between MN application and maximuvi response) and increase in the LDF .(maximum cutaneous blood flow) compared to those of the control sites. 2. Data from the ultrasound treated sites after 10 min showed no difference in the T0 and T but significant increase in the LDF compared to those of the control sites. 3. Data from ultrasound trvated sites both after 15 sec and 10 min showed significant increase in basal cutaneous blood flow(LDF) compared to those of the control sites. 4. There was no difference between the ultrasound treated sites and the control sites in the skins surface temper ature. Conclusion : The results of this study suggest that ultrasound may affect the skin structure to provide skin penetration enharcement even without raising the skins surface temperature. (Korean J Dermatol 1997;35(5): 947 955)

일부도시지역 주민의 상병상태에 대한 조사연구

황성주,Hwang, Sung-Joo 대한예방의학회 1986 Journal of Preventive Medicine and Public Health Vol.19 No.2

A Health Interview Survey at Chuncheon city was conducted to assess level of illness by stratified random sampling method. Sample size was 6,007 and the prevalence of illness in period of 15 days was studied. 1) Prevalence rate of illness among Chuncheon citizen was 20.8 percent, and that of acute condition was 10.8 percent and chronic condition, 10.0 percent. 2) There was significant difference in prevalence rate by sex, especially the prevalence rate of chronic illness. 3) High positive correlation was noted between aging and prevalence rate of chronic illness. But negative correlation was noted in case of acute illness. 4) Multiple regression analysis on morbid state by socioeconomic variables was not seen to be appropriate for this survey, especially the analysis of acute illness. 5) Estimation of anual prevalence rate could not be possible because of seasonal variation of disease prevalence.

부하연결에 따른 외팔보 압전에너지 하베스터의 공진주파수 변화 해석

황성주(Sung Joo Hwang),안정환(Jung Hwan Ahn),김선중(Sun Jung Kim),김정훈(Jeong Hun Kim),송예원(Yewon Song),성태현(Tae Hyun Sung) 한국소음진동공학회 2015 한국소음진동공학회 학술대회논문집 Vol.2015 No.4

Piezoelectric cantilever beam is used in conversion of mechanical energy to electrical energy, and vice versa. But, when an external load connected to piezoelectric material, mechanical characteristic of cantilever beam is changed. We study resonance frequency shift of the piezoelectric cantilever beam according to load connection. When the external circuit changed from open to short, resonance frequency of the piezoelectric cantilever beam is changed from 40 Hz to 39 Hz. Also, displacement of the free end of the piezoelectric cantilever beam increased 2.4%. After then, we optimize resistive impedance matching for maximum power transfer. In matching case, resonance frequency is located between open and short circuit connection. Free end displacement also 21.4% decreased. This result shows that electrical load connection results in changing of mechanical characteristic like stiffness, resonance frequency, displacement.

지루 피부염과 아토피 피부염의 임상증상과 두피내 Malassezia균 분포의 비교

황성주 ( Sung Joo Hwang ),이성훈 ( Sung Hoon Lee ),김도원 ( Do Won Kim ),전재복 ( Jae Bok Jun ),정상립 ( Sang Lip Chung ),정현주 ( Hyeon Joo Jung ) 대한피부과학회 1998 대한피부과학회지 Vol.36 No.4