지각과민치아에 대한 Nd:YAG 레이저 조사의 효과

정성용,김경희,고명연,안용우,박준상,Jung, Sung-Yong,Kim, Kyoung-Hee,Ko, Myong-Yun,Ahn, Yong-Woo,Park, Jun-Sang 대한안면통증구강내과학회 2005 Journal of Oral Medicine and Pain Vol.30 No.4

The purpose of this study was to evaluate the desensitizing effects of a Nd:YAG laser (Sunlase, SUNRISE Technologies, Inc., USA) irradiation on cervically exposed hypersensitive dentine. 45 patients was irradiated with pulsed Nd:YAG laser (1.5 W, 20 Hz, 75 mJ/pulse, 4 minutes) as the experimental group, 27 patients was mock irradiated as the control group. The degree of sensitivity to the thermal and tactile stimuli were determined qualitatively with an evaporative stimulus defined as two times air blast at a distance of 3 mm from each site to be tested and with a mechanical stimulus as a slightly scratching the cervical site with a dental explorer. A qualitative registration of the degree of discomfort was determined according to a numerical pain scale(NPS) in an 11-point scale in which 0= "no pain" and 10="most excruciating pain imaginable". Recordings were assessed before treatment, immediately after, 1 and 2 weeks after treatment. Pain tolerance threshold and pulp vitality were evaluated with electric pulp tester before and immediately after treatment. 1. Desensitizing of hypersensitive dentine with Nd:YAG laser irradiation was more effective than that with mock irradiation. 2. The placebo effect of mock irradiation was recognized for severe sensitive teeth($NPS\;{\geqq}\;6$), but not for moderate sensitive teeth(NPS < 6). 3. Laser irradiation did not affect the pain tolerance threshold and pulp vitality of the hypersensitive teeth. 4. Desensitizing effect of laser irradiation for the hypersensitive teeth had been continuing at least 2 weeks. It was concluded that desensitizing of hypersensitive dentine with a Nd:YAG laser is effective and the maintenance of the positive result was more prolonged than the placebo effect.

유한한 길이의 유연한 실린더 후류 유동에 미치는 flexibility 영향

정성용(Sung Yong Jung) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.5

도시교통 혼잡비용과 대기오염의 적정수준 결정에 관한 연구

정성용(Jung Sung Yong),김운수(Kim Woon Soo) 한국지역개발학회 1995 韓國地域開發學會誌 Vol.7 No.2

Today, most CBD areas in major cities suffer from traffic congestion, which not only causes higher travel time, but also results in worsened air pollution. Motor vehicles are the greatest single contributors to urban air pollution due to the sheer volume of their emissions per mile driven. The basic objective of this research is to develop a methodology through which both transportation network performance and urban air quality can be substantially improved. We present a mathematical programming model(Nonlinear Static Programming Model : NLSPM) that jointly minimizes transportation costs and automobile pollution impacts, using both the user-optimum and the system-optimum approach. The combined model must also properly deal with the interactions between travel time, traffic flow and speed, link capacity investment decisions, vehicle emission/diffusion, and the resulting air pollution concentrations. Based on the numerical analysis of the combined model for different Origin-Destination demands and meteorological conditions over a hypothetical network, we then figure out the social optimum level of traffic congestion and air pollution concentrations in the transpotration network.

[가솔린엔진부문] 냉시동시 배기 저감을 위한 시동 배기가스 점화 기술에 관한 연구

정성용(Sung-Yong Jung),송대근(Dae-Keun Song),조용석(Yong-Seok Cho),김득상(Duk-Sang Kim),이윤석(Yoon-Seok Lee) 한국자동차공학회 1999 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1999 No.11_1

In order to reduce the exhaust emissions from gasoline-powered vehicles, the Cranking Exhaust Gas Ignition (CEGI) technology, which reduces catalyst warmup time, was developed in this study. The CEGI technology enables catalysts to reach the light-off temperature (LOT) within several seconds after engine cracking by burning fuel-air mixture in the exhaust pipe using glow plugs. Results from an experimental study showed that the catalyst reached the LOT in a sufficiently short period of time when the operation time of CEGI exceeds 4 seconds. The optimal operating time of CEGI technology, a hydrocarbon adsorber was applied to the catalytic converter, to reduce the first peak of the HC emission during the cranking period. Experimental results show that CO and THC emissions during the first 300 seconds of cold start are reduced by 97.3% and 59.1% respectively.

COSYSMO를 이용한 SUAV 체계에 대한 SE 비용추정에 관한 연구

정성용(Sung Yong Jung),박인경(In Kyoung Park) 한국경영과학회 2008 한국경영과학회 학술대회논문집 Vol.- No.-

Organization wishes to develop newer and more complex system according as social structure is more complex and a technology develops more. Therefore, field of system engineering in development of new system is realized by all-important essential boundary. However cost of SE have considered restrictively being not about SE cost having applied SE. About this problem, this study provides COSYSMO as model for SE cost estimation, as the application example, estimate SE cost for smart UAV system applying COSYSMO in PRICE Trueplanner.

원형 및 사각형 단면 형상을 가진 tandem 실린더의 gap flow 유동현상 규명에 관한 연구

정성용(Sung Yong Jung),박한욱(Hanwook Park) 한국가시화정보학회 2020 한국가시화정보학회지 Vol.18 No.2

Problems related with flows around structures are typical in various engineering fields. The characteristics of these flow structures depend strongly on the shape of the body. The flow regime around square cylinders which are also employed in various applications has also been investigated. In addition to a single body, flows past closely spaced structures arranged in tandem are observed in numerous practical applications. In this study, the flow characteristics around the circular and the square cylinder were investigated according to S/D. The velocity fields and Reynolds stress of the single cylinders were acquired to explain the flow behaviors between tandem cylinders. The differences observed in the flow behaviors of square and circular cylinders were studied. The flow patterns around two tandem cylinders can be classified into three types of wake interference behaviors according to S/D. This is related with the flows between cylinders.

광통신용 파장 대역에서 동작하는 체적 홀로그래픽 필터

정성용(Sung-Yong Jung),양병춘(Byungchoon Yang),이병호(Byoungho Lee) 대한전기학회 1998 대한전기학회 학술대회 논문집 Vol.1998 No.11

부동산경매 위험요인이 낙찰가격에 미치는 영향에 관한 연구

정성용(Sung-Yong Jung) 한국주택학회 2009 주택연구 Vol.17 No.3

This study has analyzed the impact of the risk factors on the selling price in the real estate auction market. To resolve the potential multi-collinearity and heteroscadesticity problems from a hedonic price model, the study model is constructed only to reflect the market and auction risk factors. The risk premium which is operationally defined as the margin between the appraisal value and the selling price, is regressed by market and auction risk factors. The empirical result confirms that risk factors, caused by the uncertainty of the real estate auction, influences significantly on the selling price. The selling price is dropped down by the factors like the number of unsuccessful bids, status of physical conditions of buildings, liens and subrogated performance costs. The results of the random coefficient model shows that coefficinets associated with housing price index variations, subrogated performance costs and the number of monthly rental tenants are varied by the random factor. This result implies that coefficients of risk-related variables are not fixed but varying coefficients. The variation of coefficient is caused by the investor's risk attitudes and uncertainty. The main finding of this study is that the impact of the risk factor in real estate auction is not constant. 경매부동산은 다양한 잠재적 위험요인에 따른 위험비용이 내재되어 있다. 부동산경매낙찰가격에 관한 선행연구는 주로 헤도닉 가격모형을 이용하고 있으나, 헤도닉 가격모형은 부동산 특성변수와 경매특성변수간의 다중공선성 및 이분산성 문제를 유발할 수 있다. 본 연구에서는 헤도닉 가격모형의 잠재적인 다중공선성 및 이분산성 문제를 극복하기 위하여, 부동산 가격특성 요인을 기술적으로 배제하고, 경매특성 및 각종 위험요인만을 반영하는 경매위험비용모형을 구축하였다. 실증분석은 2005년 1월부터 2009년 2월까지 법원경매로 낙찰된 물건 중에서 대구광역권에 소재한 원룸 및 다가구주택 경매자료를 이용하여 실시하였다. 본 연구의 실증분석결과에 의하면, 유찰횟수, 건물상태 등과 같은 경매특성요인은 낙찰가격 결정의 중요한 변수임이 재확인되었다. 경과년수, 지수변동률, 지역더미 등과 같은 시장변동요인은 경매위험비용의 주요결정요인으로 판명되었다. 대항력임차인수, 인도명령자수, 유치권유무, 인수금액, 인수금액비율 등은 경매위험비용의 상승요인으로 확인되었다. 확률계수모형 분석결과에 의하면, 주택가격 지수변동률, 임차인수, 대항력임차인수, 인수금액, 인수금액비율과 관련된 계수는 고정계수가 아니라 확률적으로 변화하는 확률가변계수인 것으로 입증되었다. 계수의 확률적 변동은 부동산 경매정보의 부정확성, 추가적인 비용부담의 불확실성 및 경매투자자의 위험선호성향(위험기피적, 위험선호적)으로부터 기인하는 것으로 추측된다. 경매부동산 낙찰가격은 정보의 부정확성, 미래불확실성, 투자자의 투자성향 등과 같은 확률적 요인이 크게 영향을 미치기 때문에, 고정계수모형보다 확률적 변동을 설명할 수 있는 확률계수모형을 적용하는 것이 바람직하다.

유전자 알고리즘을 이용한 강의실 배치문제

정성용(Jung sung-yong),김태식(Kim Tae-sik) 한국정보과학회 1998 한국정보과학회 학술발표논문집 Vol.25 No.1B

유전자 알고리즘(Genetic Algorithms)은 전형적인 Combinatorial Optimization 문제에 적용되는 최적해 탐색 알고리즘이다. 본 연구에서는 유전자 알고리즘을 이용하여 다양한 매개변수로 인해 최적의 값을 쉽게 얻을 수 없는 대학의 강의실 배치문제를 해결하고자 하였다. 본 연구에서는 강의실, 강의실의 수용학생수, 개설강좌수, 개설강좌당 수강신청인원등 4개의 매개변수를 이용하여, 강의실에 개설가능한 강좌의 유형을 정하고, 각 강좌별로 수강신청한 학생의 수가 강의실의 최대 수용인원을 넘지 않도록 하는 조건에서 약 88.9%의 만족도를 얻었다.

통행시간가치의 도시공간상 변화패턴 특정에 관한 연구

정성용(Jung Sung Yong) 한국지역개발학회 1994 韓國地域開發學會誌 Vol.6 No.2

This paper addresses the problem of constant-coefficient travel demand model for an urban travel demand estimation and introduces the specification method of spatially varying coefficient models into the context of the logit model. The potential heteroscedasticity problem in a spatial logit model using expansion method was overcomed by respecifing the structure of conditional indirect utility and validated by a series of structural tests. The empirical result from the spatial logit model suggest that the coefficient of travel time variables in travel demand models vary significantly over an urban space. The following patterns of spatial variability are observed from the empirical models. First, the coefficient of auto in-vehicle travel time variable is smaller for those who travel a longer distance than for those who travel a shorter distance, perhaps because the relative impact of traffic congestion is smaller for the long distance traveller. Second, a commuter with a high income values his or her bus travel time more than a low income commuter beacuse the rich considers that buses are inferior to autos. Based on the empirical result obtained from this study, I conclude with high confidence that spatially varying travel demand model as specified by the expansion method provide a significant improvement in explanatory power over to traditional model.