• 한국정밀공학회지
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• 제27권2호
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• pp.78-85
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• 2010

The remanufacturing system is a series of industrial process in which worn-out products are restored to like-new condition. The remanufacturing system is differ from the repair system not only process characteristics but also product characteristics. So, it is required to design another model for the remanufacturing system which is distinct from the repair system and also performance index is required for the remanufacturing system. Therefore, in this paper we suggest the availability model for remanufacturing system by using Markov Process. This model represents each of the states of the remanufacturing system. Also performance indexes of remanufacturing system are introduced. Performance indexes are consisting of part reuse frequency and time, part disposal frequency and time. As a result, we can have a choice and control the proper part and offer useful information during the remanufacturing by using these availability model and performance indexes.

• 한국자동차공학회논문집
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• 제15권4호
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• pp.47-53
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• 2007

A bearing is one of core parts in automobile. Rubber seal of the bearing is important to improve performance of bearing, formed by hot-press die of rubber seal for the intricate shape. In this study, formed tools are used to machine die of bearing rubber seal and the machining operation is classified into the several process of high precision. Design of experiments is used to optimize selection of the formed tools for the efficient machining of the hot-press die. The cutting force, tool wear and tool life are determined to characteristics. And, the clearance angle, the rake angle and the length cutting edge are considered as the major factors. Experiments are repeated to use one-way factorial design, and tool life is predicted by regression model.

• 한국수산과학회지
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• 제36권6호
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• pp.573-577
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• 2003

Effects of 4-nonylphenol (4-NP) on mixed function oxygenase (MFO) in the kidneies of rockfish (Sebastes schlegeli) were investigated. The cytochrome P45O (CYP) contents and NADPH cytochrome P450 reductase, NADH cytochrome b5 reductase and 7-ethoxyredorufin-O-deethylase (EROD) activities of microsome, glutathione S-transferase (GST) activity of cytosol in rockfish exposed to 4-NP for 7 days using an intraperitoneal injection (25 mg/kg) were quantitatively determined. The GST activity of rockfish exposed to 4-NP were higher, up to 5.2 times higher, than those in the control fish. The activities of NADPH-and NADH-dependent reductases were inhibited. On the other hand, CYP contents and EROD activity of the 4-NP exposed fish demonstrated neither an increasing or decreasing trend.

• 한국기계가공학회지
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• 제5권4호
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• pp.59-64
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• 2006

High Speed Machining(HSM) reduces machining time and improves surface accuracy because of the high cutting speed and feedrate. Development of HSM makes it allowable to machine difficult-to-cut material and use small-size-endmill. It is however limited to cutting condition and tool material. In the machining operation, it is important to check main parameter of tool life and select optimal cutting condition because tool breakage can interrupt progression of operation. In this study, cutting parameters are determined to 3 factors and 3 levels which are a spindle speed, a feedrate and a width of cut. Experiment is designed to orthogonal array table for L9 with 3 outer array using Taguchi method. Also, it is proposed to inspect significance of the optimal factors and levels by ANOVA using average of SN ratio for tool life. Finally, estimated value of SN ratio in the optimal cutting condition is compared with measured one in the floor shop and reduction of loss is predicted.

• Journal of Pharmaceutical Investigation
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• 제21권4호
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• pp.247-251
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• 1991

Effects of aluminum magnesium hydroxide (A) and cimetidine (C) on the pharmacokinetics of minocycline (M) were investigated in female rats. Blood samples were collected at various time intervals until 36 hrs following oral dosing of drugs. Plasma minocycline concentrations were determined by HPLC. Control group (M), $T_1$ group (M+A), $T_2$ group (A+M after 2 hrs), $T_3$ group (M+A after 2 hrs), $T_4$ group (M+C) and $T_5$ group (C+M after 2 hrs) were divided to examine interaction of the drugs with minocycline. Plasma minocyline level-time curves were well described by two-compartment open model with first-order absorption in rats. Antacid treatment was associated with reduced of 71.0, 45.9, 35.7% in minocycline absorption rate $constant(K_{\alpha})$, maximum plasma $concentration(C_{max})$, and relative $bioavailability(F_{rel})$, respectively. Cimetidine treatment group exhibited no significant changes in plasma level-time curve when compared with control group and did not affect minocycline absorption as by any of these three parameters.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권5호
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• pp.601-605
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• 2010

본 논문에서는 부울 함수 간략화에 사용되는 Karnaugh Map 기법 학습을 위한 지능형 튜토링을 지원하는 GBL(Game based learning) 콘텐츠를 제안한다. 이 GBL 콘텐츠는 게임 기반 학습과 지능형 튜토링 시스템이 가지고 있는 장점을 결합하여 게임 요소를 통하여 학습자의 흥미를 이끌어 학습에 몰입할 수 있도록 하고, 지능형 튜토링 모듈을 통하여 몰입감을 해치지 않는 수준에서 적응적 피드백을 제공한다. 본 콘텐츠의 학습 효과를 검증하기 위해 실제 학습 환경에서 실험 집단과 통제 집단의 학업성취도를 비교한 결과 유의미한 차이를 확인할 수 있었다.

• Transactions on Electrical and Electronic Materials
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• 제4권6호
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• pp.28-31
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• 2003

Copper CMP in terms of the effect of slurry chemicals (oxidizer, corrosion inhibitor, complexing agent) on the process characteristics has been performed. Corrosion inhibitors, benzotriazole (BTA) and tolytriazol (TTA) were used to control the removal rate and avoid isotropic etching. When complexing agent is added with H$_2$O$_2$ 2 wt% in the slurry, the corrosion rate was presented very well. In the case of complexing agent, it was estimated that the proper concentration is 1 wt%, because the addition of tartaric acid to alumina slurry causes low pH and the slurry dispersion stability become unstable. There was not much change of the removal rate. It was assumed that BTA 0.05 wt% is suitable. Most of all, it was appeared that BTA is possible to be replaced by TTA. TTA was distinguished for the effect among complexing agents.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.17-18
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• 2007

The etching characteristics of Zinc Oxide (ZnO) and etch selectivity of ZnO to $SiO_2\;in\;BCl_3$/Ar plasma were investigated. It was found that ZnO etch rate shows a non-monotonic behavior with increasing both Ar fraction in $BCl_3$ plasma, RF power, and gas pressure. The maximum ZnO etch rate of 50.3 nm/min was obtained for $BCl_3$ (80%)/Ar(20%) gas mixture. The plasmas were characterized using optical emission spectroscopy (OES) analysis measurements while chemical state of etched surfaces was investigated with X-ray photoelectron spectroscopy (XPS). From these data the suggestions on the ZnO etch mechanism were made.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.87-90
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• 2015

기존의 OTP(One-Time Password) 인증 시스템은 OTP 단말을 휴대해야하는 불편함이 있으며 생성한 OTP 값을 그대로 OTP 단말에 출력하기 때문에 주변에 쉽게 노출될 수 있다. 또한, 기존의 9자리 패턴 인식 방법은 같은 패턴 지점을 연속으로 인식시킬 수 없고 패턴을 그리는 경로에 다른 패턴 지점이 포함될 수 있다는 한계가 있어 제한적인 패턴 결과를 가진다. 따라서, 본 논문은 원형 배치된 패턴 지점 기반의 OTP 대칭 값 패턴 인증 시스템을 통해 OTP 단말을 휴대할 필요가 없게 하고, OTP의 각 자리 값을 대칭 값으로 표현함으로써 OTP 값의 노출을 막는다. 또한 모든 OTP 값으로 패턴 인식이 가능하도록 하기 위해 패턴 지점을 원형 배치하는 방법을 제안한다. 이는 직접적으로 OTP 값이 노출될 가능성을 감소시키고, OTP 인증을 위한 패턴 인식에서 패턴 지점을 원형 배치함으로써 모든 OTP 값이 패턴으로 변환될 수 있도록 한다. 본 논문은 패턴 지점의 원형 배치와 대칭 값을 이용한 OTP 인증 시스템을 제안하여 새로운 OTP 인증 방법으로 패턴 인식을 적용할 수 있도록 한다.

• Nuclear Engineering and Technology
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• 제30권2호
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• pp.112-127
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• 1998

The present study is to assess the applicability of the best-estimate thermal-hydraulic codes, RELAP5/MOD3.2 and CATHARE2V1.3U, to the analysis of thermal-hydraulic behavior in PWRs during midloop operation following the loss of RHRS. The codes simulate an integral test, BETHSY 6.94, which was conducted in the large scale test facility of BETHSY in France. The test represents the accident where the loss of RHRS occurs during midloop operation with the pressurizer and upper head vents open and the sight level indicator broken. Besides, the hot legs are half filled with water and the upper parts of the primary cooling system are filled with nitrogen, with a letdown line open and only one SG available. The purposes of this study are to understand the physical phenomena associated with reflux cooling in the 5G U-tubes when noncondensable gas is present under low pressure and to assess the applicability of the codes to simulate the loss of RHRS event by comparing the predictions with the test results. The results of the study may contribute to actual applications for plant safety evaluation and description of the emergency operating procedure.