Transient Engine Test Bed를 이용한 가솔린엔진의 F/E 및 Emission개선에 관한 연구

이상수(Sangsu Lee),이창준(Changjun Lee),이근봉(Keunbong Lee),이문식(Moonsig Lee),이정근(Jeongkeun Rhee) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The fuel economy and emissions in a developing port injection gasoline engine with manual transmission were studied using a transient engine test bed. Because the fuel economy and emissions in the first few minutes during engine warmup show great importance, the first ECE cycle in NEDC mode was simulated. To match the fuel economy and emission levels with the roller bed test results, driver model on clutch and acceleration pedal actions were thoroughly adjusted to match engine speed and engine load of the vehicle. The faster catalyst light-off was investigated by varying crank-to-run air-fuel ratio and idle spark timing. and results showed that slightly lean air fuel ratio was more effective in heating lip the catalyst than retarding idle spark timing in terms of fuel economy. The additional engine EMS calibrations were performed to improve cruise operation points and idle regions using DOE method with L9 orthogonal test array. The overall results showed that both the fuel economy and emissions were improved during first ECE cycle in the NEDC mode test by the EMS calibration performed in this study.

본존스칼라 방법을 이용한 층류확산화염에 대한 수치해석적 연구

이상수(Sangsu Lee),신동흔(Donghn Shim),성낙원(Nakwon Sung) 한국자동차공학회 2002 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2002 No.5_1

A simple combustion analysis was done in prior to developing a combustion analysis code of full chemistry. To analyze the laminar diffusion name established on the coflow burner, the governing equations were derived on 2-D axisymmetric plane. These equations were transformed into 4 simplified equations about radial velocity, axial velocity, vorticity, and conserved scalar. The discrete equations were solved on a nonuniform grid system by Newton's method. It was difficult to find appropriate initial guess for Newton iteration in calculating the reacting now with high temperature gradient. As a remedy for the problem, the result with fixed temperature field was used for the initial guess. To solve AX=B type matrix problem, a direct sparse matrix solver included in the commercial FORTRAN compiler was used. The distributions of temperature and major species were compared with the experiment by Xu[1]. The algorithm was proved to be feasible for the future study using multi-step reactions on finer grid system.

반경류형 금속품 DPF의 성능에 관한 연구

이상수(Sangsu Lee),조규백(Gyubaek Cho),김진현(Jinhyun Kim),김홍석(Hongsuk Kim),이의성(Euisung Lee),오권오(Kwonoh Oh),한승한(Seunghan Han),김경재(Kyungjae Kim),정용일(Yeongil Jung) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The performance of radial type metal foam DPF was studied. The radial type metal foam DPF was built by rolling INCOfoam® HighTemp into a hollow cylinder and installing it inside the DPF can with a conical flow reflector. Several types of metal foam DPF were tested. They are different in filter thickness, mean pore size, and Platinum coating with 2.5g/l or not. The test mode was determined to simulate the on-road vehicle speeds on the engine bench. In the testing vehicle speeds, the SOF in total PM emissions was so high due to the low engine load that the PM reduction via Platinum coating was dominant. Compared with cordierite filters, the radial type metal foam DPF showed similar PM reduction rate but lower increase in Δp during engine run at steady engine conditions due to their large mean pore sizes. Compared with axial type metal foam DPF studied in previous studies, the radial type metal foam DPF provides 7 times higher filtering area which enables higher PM reduction rate and lower Δp across DPF. The Platinum coated radial type metal foam filter was proven to be suitable for the replacement for cordierite filter in that it provides slow increase in Δp but comparable PM reduction rate.

탄소의 상평형을 이용한 수트생성 메커니즘

이상수(Sangsu Lee),김홍석(Hongsuk Kim),조규백(Gyuback Cho),성낙원(Nakwon Sung) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1

The soot inception process inside a diesel engine was studied by the analytical models. With the general chemical reaction mechanism for the soot formation, the phase equilibrium concept is considered for the inception process of soot. In the phase equilibrium concept, the soot is formed from the phase change of gaseous carbon atoms as the phase change of gaseous precursors into solid soot under the condition of saturation pressure. These soot models are implemented into the KIVA-3V code. The results from the phase equilibrium model show that the cold fuel-rich core of spray is the main source of soot inception rather than the high temperature flame. The modified soot model showed reasonable results comparing with the experimental results and similar soot distribution inside a cylinder to the other experimental observations.

경유중 황성분이 Metal Foam 필터의 성능에 미치는 영향

이상수(Sangsu Lee),오권오(Kwonoh Oh),이의성(Euisung Lee),김홍석(Hongsuk Kim),정용일(Yongil Jung),조규백(Gyubaek Cho) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1

The effects of sulfur contents on the performance of the metal foam DPF (Diesel Particulate Filter) were investigated. The metal foam, INCOFOAM? High Temp, was axially stacked in the exhaust pipe to reduce PM emissions. LSD (Low Sulfur Diesel) fuel which has sulfur content of about 300 ppm and ULSD (Ultra Low Sulfur Diesel) fuel which has sulfur content of below 50 ppm were used to compare the emissions. When the DOC (Diesel Oxidation Catalyst) was installed upstream of DPF and the LSD fuel was used, the PM reduction rates at high exhaust temperature were deteriorated because the DOC oxidized sulfur dioxide at high exhaust temperature which eventually forms sulfate particles during dilution. With DOC, BPT (Balance Point Temperature) was lowered from 420℃ to 360℃ due to the NO₂ formation inside the DOC, which is favorable for the DPF regeneration. Accordingly, when ULSD was used, the combination of DOC and DPF showed PM reduction rate of 70% and relatively low pressure difference across DPF, which are acceptable performance for DPF.

SMA 커넥터를 이용한 3축 펄스 탐지기

이상수(Sangsu Lee),박용배(Yong Bae Park) 한국전자파학회 2017 한국전자파학회논문지 Vol.28 No.9

본 논문에서는 SMA 커넥터를 이용한 3축 펄스 탐지기의 동작 특성을 분석한다. 상용 시뮬레이터를 이용하여 3축 펄스탐지기를 모델링하고, 펄스가 인가됐을 때 동작 특성을 확인 및 분석하여 펄스 탐지기로써의 응용이 가능함을 확인한다 In this paper, the performance characteristic of 3 dimensional pulse detector using SMA connector is analyzed. Modeling of 3D pulse detectors is done in a commercial simulator. When a pulse is incident on the detector, we analyze the performance characteristics of the detector and verify the feasibility of the pulse detector.

산소부화를 이용한 디젤기관에서의 수트 및 NOx 저감에 대한 수치해석적 연구

이상수(Sangsu Lee),성낙원(Nakwon Sung) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

A numerical study was performed to investigate the effects of oxygen enrichments on the emissions of soot and NOx from a diesel engine. The flow, fuel injection, combustion and emissions inside a diesel engine were calculated using a modified KIVA code. Oxygen content in the intake air was varied from 17% to 25% by volume. <br/> As oxygen content was increased, the fuel was burned fast and more resulting in increased combustion temperature and improved fuel consumption. The increased temperature enhanced the dissociation into OH, N and O radicals and the pyrolysis of fuel. Soot emission was reduced by half with 25% oxygen because of the increased soot oxidation by OH radical, but NOx was increased by three times because of the increase of temperature and concentrations of O and N radicals. Ignition delay was reduced by oxygen enrichment, and injection timing was retarded in order to alleviate the shape increase of NOx. Although oxygen enrichment has the same problem of soot-NOx tradeoff as other technologies, it can be used appropriately with after treatment technology to reduce soot and NOx simultaneously.

가상현실(VR) 내에서 구현되는 도서관 인터페이스 시스템에 관한 연구

이상수 ( Sangsu Lee ) 한국디지틀도서관포럼 2016 디지틀 도서관 Vol.84 No.-

우리 삶에 있어 독서는 빼 놓을 수 없는 부분이다. 다양한 책을 접할 수 있는 공간 중 하나인 도서관 이용률이 안타깝게도 매해 큰 폭으로 감소하고 있다. 이용률이 감소하는 여러 이유가 있지만, 그 중 가장 큰 이유는 물리적인 접근성이 떨어지기 때문이다. 산간이나 외딴 섬 같은 경우에는 이용이 더욱 어렵다. 또한, 운영시간 제한의 문제, 책 예약·대출의 어려움 등 문화적 혜택을 받기 어려운 지방일수록 더욱 문제점이 커진다고 볼 수 있다. 그렇다면 이러한 문제를 해결하고 다양한 조건에 있는 사람들이 시공간의 제약을 극복하고 도서관을 이용하여 다양한 서적을 읽으려면 어떻게 해야 할까? 이는 현재 전 세계적으로 큰 화제가 되는 가상현실 (virtual Reality)의 개념과 VR 디바이스 중 하나인 몰입형 헤드셋 HMD (Head Mount Display)를 사용하여 구현되는 가상현실 도서관이 그 답이 될 수 있다. VR 헤드셋은 현존하는 디지털 기기 중 최상의 몰입감을 제공하고 시공간의 제약을 극복해 주는 시스템이다. 그렇다면 가상현실 도서관은 어떻게 구성되어야 기존의 도서관, 디지털 북 등의 매체보다 훨씬 더 높은 수준의 사용자 경험을 제공할 수 있을까? 어떠한 인터페이스가 적용되어야 더욱 효과적으로 이용할 수 있을까? 시공간의 문제를 가상현실(Virtual Reality)로 극복하여 실제 도서관을 이용하는 것과 비교하여 가상현실 도서관을 이용했을 때 확연한 장점과 더 나은 사용자 경험을 주기 위해 본 논문은 가상공간 (VR) 내에서 구현되는 도서관 인터페이스 시스템을 제안한다. Reading plays a crucial role in the development of human brain. Unfortunately, library, a place where a variety of knowledge can be found, is decreasing by a large margin every year. In today`s busy modern society, people do not have the time to physically visit libraries. One of the main reasons why people are not using a library is because of the geographical constraint of libraries. If a person lives in a remote location especially on an island or mountainous areas, it becomes even more difficult to use a library. In addition, the problem of limited opening hours and difficulties of book reservation also plays a role in the decreased use of library. VR(Virtual Reality) technology and immersive headset HMD(Head Mount Display) could be the solution to the problems above. VR headset is a system that provides the ultimate immersion and overcomes the constraints of time and space. How should a virtual reality library be configured to provide a higher level of user experience than traditional media such as a library or a digital book? What kind of interface should be used for a successful user-experience? This paper proposes an interface within the virtual reality library in order to give a better user-experience and benefits compared to the traditional library.

책임원칙에 근거한 미국 형법상 Felony Murder 이론의 검토

이상수 ( Sangsu Lee ) 안암법학회 2016 안암 법학 Vol.0 No.51

형법에서 책임이란 위법한 행위를 한 행위자에 대한 비난가능성을 의미한다. 따라서 비난가능성으로서 책임이 인정되지 않는 경우에는 형벌도 부과될 수 없는 것이 원칙이다. 미국 형법에서도 책임의 본질은 비난가능성이라고 할 수 있다. 보통법상의 범죄가 형성되고 그 범죄이론이 전개되던 초기에는 비난할만한 심리적 상태를 전혀 포함하지 않은 행위들까지도 범죄 결과가 발생하기만 하면 그 결과에 대해서 무조건 형사책임을 귀속시키는 결과책임주의 시대가 있었다. 그러나 보통법 후기 시대 이후 그 결과가 행위자의 비난가능한 심리적 상태, 즉 범죄의사(mens rea)에서 비롯된 경우에만 형사책임을 부과할 수 있다는 책임원칙이 확립되어 왔다. 따라서 미국 형법에서도 범죄의사는 책임비난의 본질적 요소가 된다. 보통법(Common Law)상 살인(murder)은 원칙적으로 범죄의사로서 사전 악의(malice aforethought)를 요건으로 하지만, 일정한 유형의 사망의 결과에 대해서는 이러한 범죄의사 없이도 살인죄(murder)가 성립한다. 중범죄 살인죄 이론은 일반적으로 중범죄(felony)의 수행 과정에서 발생하는 사망의 결과에 대해서 살인죄의 성립을 인정한다. 즉, 중범죄 살인죄 이론의 법리는 중범죄자(felon)가 중범죄의 수행과정(in the furtherance of felony)에서 고의로 사망의 결과를 낳았든 아니면 무모하게, 과실로 또는 심지어 과실없이 사망의 결과를 낳았든 상관없이 살인죄의 형사책임을 부과한다. Felony Murder 이론에 대해서는 책임원칙과 인과관계의 두 가지 측면에서 비판이 제기된다. 행위자가 행위 당시 예측하지 못한 사망의 결과에 대해서 그 죄책을 부담시키는 것이 책임원칙상 타당한지 여부가 문제되고, 또 사망의 결과를 야기하지 않고 예견할 수도 없었던 행위자에게 그책임을 귀속시키는 것이 인과관계 법리상 허용되는지도 문제된다. 미국 법원과 학자들은 Felony Murder 이론의 문제점을 직시하고 그성립범위를 제한하고자 시도하였다. 모범형법은 이 이론에 대한 비판에 부응하여 강도, 강간, 방화, 중범죄목적 야간주거침입, 납치, 중도주죄와 관련된 사안에 한하여 Felony Murder 이론의 적용을 허용한다(제210장 제2조 제(1)항). 중범죄를 범하는 도중에 사망의 결과가 발생하였다 하더라도, 사망의 결과에 대하여 행위자의 범죄의사가 인정되지 않는 경우까지 형사책임을 부과하는 것은 결과책임을 인정하게 되어 타당하지 못하다. 따라서 Felony Murder 이론은 그 근원지인 영국의 경우처럼 폐지되거나 사망의 결과에 대하여 최소한 행위자의 귀책사유를 요건으로 하는 방향으로 개선되어야 할 것이다. Today, the principle of culpability is a common criminal doctrine prevailing in not only civil law system countries but also Anglo-American law system countries. National penal authority should be executed for the purpose of guarantee of people``s rights and its procedures and limitations should be abided by. In American criminal law, the nature of culpability is also blameworthiness. Criminal liability can be imposed on a person who meets the requirement of intent, knowledge, recklessness or criminal negligence as criminal state of mind(mens rea). Since the late period of common law, the principle of culpability that means criminal punishment can be justified only when the results are due to the culpable mens rea of the conductor. Therefore, criminal state of mind(mens rea) is also the essential element that constitutes culpability in American criminal law. Although murder in the common law generally required ``malice aforethought``, any death occurring during the course of a felony is labeled murder even without such a mens rea. The felony murder doctrine imposes liability for murder whether a felon kills intentionally, recklessly, negligently or even non-negligently. This obviously clash with the notion of causation. The doctrine is too broad and it has been required to find ways to limit its application. The “in furtherance”, “agency” and “provocative act” theories, duration of the felony and limitation on the predicate felony (independent felonious purpose doctrine and inherently dangerous felony rule) theory have been suggested as restrictions on the felony murder doctrine. The Model Penal Code also limits the doctrine allowing its application only in cases involving robbery, rape, arson, burglary, kidnapping, or felonious escape. Even then, the Code raises only a presumption that the defendant was reckless with regard to the possibility of death. That presumption is rebuttable by the defendant. It is advisable that the felony murder doctrine should be abrogated or modified to require mens rea for the conformity to the principle of culpability.

가솔린엔진의 성능 및 연비측면에서의 비교분석에 관한 연구

이상수(Sangsu Lee),김영중(Youngjoong Kim),이정근(Jungkeun Rhee) 한국자동차공학회 2018 한국자동차공학회 학술대회 및 전시회 Vol.2018 No.11