• 품질경영학회지
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• 제41권2호
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• pp.185-196
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• 2013

Purpose: This paper is focused on introducing the Automotive Functional Safety International Standard-ISO 26262 and proposing effective countermeasures of ISO 26262. Methods: We studied collected data about ISO 26262 and analyzed the relationship between ISO 26262 and Quality 5 Star of Hyundai Kia Motors for the integrated product development process. Results: Results showed the product development process for the integration plan between ISO 26262 and Quality 5 Star. In addition, we added an entry about the functional safety in the evaluation item of Quality 5 Star System. Conclusion: In order to introduce ISO 26262 effectively, we proposed ISO 26262 requirements and functional safety concept to be added to Quality 5 Star.

• 한국정밀공학회지
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• 제26권12호
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• pp.131-137
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• 2009

Recent technological advances made a vehicle more intelligent to increase safety and comfort. An intelligent vehicle provides drivers with safety warning information through audible sounds, visual displays, and tactile devices. However, elderly drivers have been known to decrease the physical and cognitive abilities such as muscular strength, hearing, eyesight, short term memory, and spatial perception. Therefore, possible age-related deficits should be considered to design an effective warning system. This paper aims to evaluate the impact of advancing age on response performance on audible safety warnings which are widely used for alerting driving hazards. In order to understand the effect of age-related hearing loss and movement slowing, three sound characteristics (frequency, intensity, and period) and three age groups (younger, middle, and older) are considered. Data was drawn from 38 drivers who drove a simulated rural road in a driving simulator. Experimental results show that age influences driver's response performance. In conclusion, the appropriate range of a warning sound is suggested.

• 한국자동차공학회논문집
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• 제20권2호
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• pp.30-37
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• 2012

Pneumatic Active Engine Mount(PAEM) with open-loop control system has been developed to reduce the transmission of the idle-shake vibration induced by engine effectively and economically. A solenoid valve installed between PAEM and vacuum tank is on-off switched by the Pulse Width Modulate(PWM) control signal to decrease the dynamic stiffness of the engine mount. This paper presents the methodology to identify the optimal values of control parameters of a PAEM, i.e, turn-on timing and duty ratio of PWM signal for 6 different idle driving conditions. A scanning algorithm was first applied to the vehicle test to obtain the approximate optimal control parameters minimizing the vibration at front seat rail and at steering wheel. Then the PAEM system identification was fulfilled to find accurate optimal control parameters by using multi-layer neural networks of Levenberg-Marquardt algorithm with vehicle test data.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.45-53
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• 2009

Die casting process of Mg alloys for high temperature applications was studied to produce an engine oil pan. The aim of this paper is to evaluate die casting processes of the Aluminium oil pan and in parallel to apply new Mg alloy for die casting the oil pan. Temperature distributions of the die and flow pattern of the alloys in cavity were simulated to diecast a new Mg alloy by the flow simulation software. Dies have to be modified according to material characteristics because melting temperature and heat capacity are different. We changed the shape and position of runner, gate, vent hole and overflow by the simulation results. After several trial and error, oil pans of AE44 and MRI153M Mg alloys are produced successfully without defect. Sleeve filling ratio, cavity filling time and shot speed of die casting machine are important parameter to minimize the defect for die casting Magnesium alloy.

• 폴리머
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• 제31권3호
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• pp.255-262
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• 2007

고분자 습도센서 막으로 사용하기 위한 두 가지 타입의 공중합체를 라디칼 중합방식에 의하여 제조하였다. 각각 공중합체는 세 가지의 단량체를 포함하여 제조하였는데, 각 단량체들은 습도 저항성, 막 안정성, 유연성, 임피던스 및 전극 부착력을 증대시키는 효과를 가지도록 하였다. 염 형태의 MDBAB는 제조된 습도 막의 임피던스를 감소시키는 효과를 보였으며 아민과 반응하여 가교 구조를 생성하였다. DAEMA, 4-VP, 및 2-EHA를 사용하여 습도막 제조를 위하여 몇 가지 조성물을 제조하였다. 특정 조성 조건에서 성능 및 장기 내구성 측면에서 우수한 결과를 얻을 수 있었다.

• 제어로봇시스템학회논문지
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• 제18권8호
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• pp.787-793
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• 2012

This paper introduces the autonomous vehicle Pharos, which participated in the 2010 Autonomous Vehicle Competition organized by Hyundai-Kia motors. PHAROS was developed for high-speed on/off-road unmanned driving avoiding diverse patterns of obstacles. For the high speed traveling up to 60 km/h, long range terrain perception, real-time path planning and high speed vehicle motion control algorithms are developed. This paper describes the major hardware and software components of our vehicle.

• Macromolecular Research
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• 제12권1호
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• pp.112-118
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• 2004

With the goal of enhancing the creep resistance of ultra-high molecular weight polyethylene (UHMWPE), we performed gamma irradiation and post-irradiation annealing at a low temperature, and investigated the crystalline structures and mechanical properties of the samples. Electron spin resonance spectra reveal that most of the residual radicals are stabilized by annealing at 100$^{\circ}C$ for 72 h under vacuum. Both the melting temperature and crystallinity increase after increasing the dose and by post-irradiation annealing. When irradiated with the same dose, the quenched sample having a higher amorphous fraction exhibits a lower swell ratio than does the slow-cooled sample. The measured tensile properties correlate well to the crystalline structure of the irradiated and annealed samples. For enhancing creep resistance, high crystallinity appears to be more critical than a high degree of crosslinking.

• 한국주조공학회지
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• 제28권3호
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• pp.136-140
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• 2008

A new concept of salt core, a melting temperature of which is lower than the solidus temperature of cast alloy, was introduced to produced an integrated casting part having a complicated inner shape or requiring under-cut in high pressure die casting or squeeze casting process. The main goal of this study is to develop a new integrated net-shape forming technology using fusible core of lower melting temperature than that of a casting alloy. This integrated net-shape forming technology would be very successful and cost-effective for producing the integrated products having a complicated inner shape or requiring under-cut. The technology for measuring and evaluating a various property of fusible core such as a thermal conductivity and thermal expansion coefficient, melting temperature was established. Also, the work space can be cleaned without a pollution inducing products.

• Tribology and Lubricants
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• 제25권1호
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• pp.61-65
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• 2009

Tribological properties of the semi-metallic friction materials containing different solid lubricants (graphite, $WS_2$, $MoS_2$) were investigated. The friction materials were fabricated with an experimental formulation and tested with gray cast iron disks. Results showed that graphite contributed to stabilize the friction coefficient during run-in processes. Also, graphite provided better fade resistance than that of $WS_2$ and $MoS_2$. At intermediate temperature ranges, however, friction materials with $WS_2$ or $MoS_2$ maintained higher friction effectiveness than that of graphite. On the other hand, friction materials containing $MoS_2$ showed increased wear rates than that with graphite or $WS_2$. Friction materials with proper combinations of two solid lubricants showed better friction and wear properties than that of the friction materials containing single solid lubricant.

• 대한금속재료학회지
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• 제49권5호
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• pp.367-373
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• 2011

This paper studies the experimental method that uses the homogeneous precipitation method to prepare mica flakes coated with anatase-type titania pearlescent pigment with urea as precipitant. The optimum technology parameters, the chemical composition, the microstructure, and the color property of resulting pigments are discussed. The coating principle of mica coated titania with various coating thickness is analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy(TEM) and tested by spectrophotometer analysis. The colored nanocrystalline pigments with different morphology and coating thickness 45-170 nm were prepared by homogeneous precipitation treatment of $TiOSO_4$(titanum oxysulfate) aqueous solutions. Characterizations on the pigments show that the pearlescent effects of the pigments depend mainly on mica size, thickness of the metal oxide deposit, its chemical composition, and crystal structure.