• Proceedings of the KAIS Fall Conference
• /
• 2009.12a
• /
• pp.279-282
• /
• 2009

Motohawk ECU(Engine Control Unit)에 의한 가솔린기관의 연료분사제어 알고리즘 연구를 통하여 연비를 절감할 수 있는 방안을 연구한다. 실제 차량엔진 ECU는 캘리브레이션 이외의 제어 알고리즘을 변경하여 구현하기가 쉽지 않으므로 상기의 프로토타입 ECU를 활용하여 연료분사제어 로직을 변경해가면서 연료분사와 관련된 여러가지 파라메터의 연구가 가능하다. 또한 프로그래밍은 Matlab과 Simulink로 구현할 수 있어서 최적연비를 얻기 위한 로직의 구현을 실시간으로 할 수 있으며 차량의 특성상 프로그램의 임베딩이 가능하여야 하므로 이러한 목적에 프로토타입 ECU에 의한 로직개발은 많은 장점이 있다. 이러한 ECU를 활용하여 여러 가지 제어 변수에 의한 최적화된 연료분사 로직의 설계 및 미치는 영향을 평가한다.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.8
• /
• pp.818-822
• /
• 2008

The purpose of this study is to develop realistic painting simulation in real-time as well as to represent the thickness of the deposited paint on the surface. The Gaussian model is used for a painting deposition model to calculate the thickness of paints. For a painting simulation, rather than implementing particle systems, we propose a new heuristic algorithm for painting process based on a few number of rays. After we find the collision points of the rays with an environment, we compute the painted area using flood-fill searching method on the texture map and visualize paint effects. We analyzed time complexity of our method to verify that our system is suitable for real-time VR applications.

• Proceedings of the KAIS Fall Conference
• /
• 2009.05a
• /
• pp.835-838
• /
• 2009

본 논문은 환경공해의 주범인 자동차의 매연을 감소할 수 있는 방법에 대한 연구이다. 자동차 매연의 주요원인은 연료의 불완전 연소와 연료 자체의 특성때문이다. 따라서 본 논문에서는 가솔린/경유 차량을 CNG/LPG 차량으로 대체하고 CNG/LPG연료의 특성을 감안하여 연료의 공급과 분사량, 분사시간을 차량 ECU에서 보내지는 신호를 기본데이터로 차량의 가속과 감속 아이들 상태에서 차량을 적응적으로 최적화 할 수 있게 실시간으로 보정데이터를 계산한다. 본 논문의 결과로 기존의 구조변경차량의 출력에서 20%이상, 배기가스 에서 10% 이상의 향상되었다.

• Journal of ILASS-Korea
• /
• v.11 no.4
• /
• pp.228-233
• /
• 2006

There are two types of electric controlled fuel injection system in the gasoline engines of common vehicles. One is fuel return system and the other is fuel returnless system according to the methods of controlling injection pressures. It is important to understand the characteristics of these system in loaming and studying of engine, but it is very difficult without a special equipment in reality. The purpose of this paper is to develop the emulation system that can be compensated with the amount of injection fuel according to various driving conditions, battery voltage, cooling water temperature, and engine speed, may be appeared in real driving, and especially can analyze the difference between the electric signal controlling the amount of injection fuel and its result, and nullity injection duration. With the developed system, we can conveniently set various and completed driving condition and so can acquire the useful information such as non-uniformity rate and mass of injection fuel using waveform analysis and measurement modules. It must be a very useful and sophisticated system to instruct and learn the features and operating states of injection system, and to study f3r improving the performance of it.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.29 no.1
• /
• pp.69-79
• /
• 2013

The aim of this study was to evaluate the effect of surface conditioning on the shear bond strength of zirconium-oxide ceramic to resin cement. A total of 120 disk-shaped zirconium-oxide ceramic blocks(3-TZP, Kyoritsu, Tokyo, Japan) were treated as follows: (1) no treatment; (2) sandblasting with 110 ${\mu}m$ aluminum-oxide(Al2O3); (3) particles tribochemical silica coating(RocatecTM, 3M ESPE). Then zirconium-oxide ceramic blocks were divided into six groups(10 for each group) and bonded with resin cement(Rely X U-200, 3M ESPE). (1) No treatment / No treatment (2) No treatment / Sandblasting with 110 ${\mu}m$ aluminum-oxide particles (3) No treatment / Silica coating (4) Sandblasting with 110 ${\mu}m$ aluminum-oxide particles / Sandblasting with 110 ${\mu}m$ aluminum-oxide particles (5) Sandblasting with 110 ${\mu}m$ aluminum-oxide particles / Silica coating (6) Silica coating / Silica coating. Each group was tested in shear bond strengths by UTM. Data analysis included one-way analysis of variance(ANOVA) and the Tukey Honestly Significant Difference test (P=0.05). Group that bonded two silica coated specimen showed a highest bond strength(P<0.05). Two silica coated surface conditioning group and air-abrasion and silica coated surface conditioning group showed significantly difference with other groups(P<0.05). Other groups had no significantly difference each other. Within the limitation of this study, Surface conditioning with Rocatec treatment to each side of specimen provided the highest bond strength.

• Polymer(Korea)
• /
• v.38 no.1
• /
• pp.98-102
• /
• 2014

Nowadays, silk fibroin receives a lot of attention as novel natural biomaterials due to its excellent biocompatibility and biodegradability. Electrohydrodynamic spraying (EHDS) is one of the method for the preparation of micro or nanoparticles by applying high voltage to the polymer solution. In this research, we fabricated silk fibroin porous microparticles by electrohydrodynamic spraying. Poly(ethylene glycol) (PEG) was added to the fibroin solution to give pores to silk fibroin microparticles. By the addition of PEG, the microparticle size was decreased despite of the decrease in conductivity and the increase of viscosity of the spraying solution. It seems that the immiscibility of silk fibroin and PEG affected much more to the microparticle size than the conductivity and viscosity. Immersing the as-sprayed microparticles into the water removed the phase-separated PEG, and finally, porous silk fibroin microparticles were prepared. The porous silk fibroin microparticles are expected to be applied as drug carriers in drug delivery or cell carriers in tissue engineering.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.369-373
• /
• 2012

최근 강화된 국내외의 배출가스 규제 조건을 충족시키기 위해, 사용자의 요구대로 연료의 분사시기와 분사량을 조절할 수 있는 CRDI ECU 제어 알고리즘의 개발이 필요하다. 따라서 본 논문에서는 산업용 CRDI 엔진 전용 ECU에 적용할 수 있는 노킹 판별 및 엔진 밸런스 보정이 가능한 노킹 분석 시뮬레이터를 개발하였다. 개발한 노킹 분석 시뮬레이터의 결과를 OBD-II 표준을 사용하여 차량 위주의 진단기를 개발하여 운전자가 직접 차량을 진단할 수 있는 운전자 중심의 진단 서비스를 제공하고자 한다. 이를 위해 자동차 고장진단 신호 및 센서 출력 신호를 유선시스템과 무선 시스템인 블루투스 모듈을 이용하여 실시간 통신이 제공 될 수 있는 OBD-II 진단기 S/W 설계 방안을 제안함으로써 차량의 연비를 향상시키고, 유해 배출가스의 발생을 최소화하여 엔진 효율성의 개선 방안을 제시하고자 한다.

• Journal of Bio-Environment Control
• /
• v.23 no.1
• /
• pp.26-30
• /
• 2014

Purpose of this study was a development of a sprayer arm auto control system that could be operated according to distance from pear trees for automation of pest control. Auto control system included two parts, hardware and software. First, controller was made with an MCU and relay switches. Two types of ultra-sonic sensors were installed to measure distance from pear trees: one on/off type that detect up to 3 m, and the other continuous type providing 0~5 V output corresponding to distance of 0~3 m. Second, an auto control algorithm was developed to control. Each spraying arm was controlled according to the sensor-based distance from the pear trees. And it could dodge obstacles to protect itself. Max and min signal values were eliminated, when five sensor signals was collected, and then signals were averaged to reduce sensor's noises. According to results of field experiment, auto control test result was better than non auto control test result. Spraying rates were 69.25% (left line) and 98.09% (right line) under non auto control mode, because pear trees were not planted uniformly. But, auto control test's results were 92.66% (left line) and 94.64% (right line). Spraying rate was increased by maintaining distance from tree.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.17 no.2
• /
• pp.118-125
• /
• 2009

Calculation of indicated mean effective pressure(IMEP) requires high cylinder pressure sampling rate and heavy computational load. Because of that, it is difficult to implement in a conventional electronic control unit. In this paper, a cylinder pressure based real-time IMEP estimation method is proposed for controller implementation. Crank angle at 10-bar difference pressure($CA_{DP10}$) and cylinder pressure difference between $60^{\circ}$ ATDC and $60^{\circ}$ BTDC($DP_{deg}$) are used for IMEP estimation. These pressure variables can represent effectively start of combustion(SOC) and fuel injection quantity respectively. The proposed IMEP estimation method is validated by transient engine operation using a common-rail direct injection diesel engine.

• Journal of Astronomy and Space Sciences
• /
• v.15 no.2
• /
• pp.427-436
• /
• 1998

The apogee manoeuvre of $KOREASAT-1{cdot}2{cdot}3$ is basic elliptical orbit transfer converting orbit plane. The KOREASAT-3 is planed for multi-burn manoeuvres using the liquid apogee engine while the $KOREASAT-1{cdot}2$ used the apogee kick motor that executes a single burn in the apogee of transfer orbit using the solid propellant. This study analyzed the multi-burn manoeuvres using the liquid apogee engine and the propellant control method and developed the simulation tools. For the purpose of precise simulation, We designed tools in the basic of orbit propagation software, COWELL5, that was developed by members of Center for Astrodynamics in Yonsei university and the results can be displayed in 3-D graphic of $STK/VO^{TM}$.