• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.984-985
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• 2014

This research investigates to analyze the effect of laser of thermally assisted magnetic recording system on diamond like carbon (DLC) layer of slider. We investigated a damaged DLC layer of slider with laser spot-induced damage and analyze the effect of the damaged DLC layer in slider dynamics. The damaged DLC layer resulted in change of flying height and air bearing stiffness pressure.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.312-312
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• 2010

기존의 박막태양전지 전면층으로 활용하는 Asahi glass는 증착공정 중에 발생하는 수소 플라즈마로 인해 FTO 기판의 투명전도막이 손상되어 태양전지의 효율 저하가 문제가 되었다. 이를 해결하기 위해 본 논문에서는 FTO 기판의 전면층을 대신하여 ZnO:Al 박막증착을 하기 위해서 회전원통형의 타겟이 장착된 DC magnetron sputtering을 가지고 성장을 시켰는데 증착하는데 있어 중요한 공정변수인 압력 및 온도 조건의 가변을 통해 이를 최적화하여 전면층에 활용하고 자 한다. 그래서 3mtorr의 압력과 $230^{\circ}C$의 온도 조건에서 두께가 약 $1{\mu}m$일 경우, $6.5{\times}10^{-4}{\Omega}cm$의 비저항과 함께 약 85% 이상의 투과도를 나타냈다. 이것은 ZnO:Al 박막이 압력과 온도의 영향에 따라 투명전도막에 많은 영향을 끼치는 것을 알 수 있었다.

• Journal of the Mineralogical Society of Korea
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• v.3 no.1
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• pp.18-33
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• 1990

각종 콘크리트 구조물의 기초공사에서 생기는 문제점 외에 시멘트와 골재자체의 반응, 즉 알카리-골재반응에 의한 물리, 화학적인 변화가 구조물에 피해를 주는 일차적인 요인으로 작용된 사례가 최근 10년간 외국에서는 잇달아 보고 되고 있다. 국내산 콘크리트 구조물에 대한 본 연구에 의하면 변성작용을 받은 이축성 석영, 자아석류가 시멘트로부터 공급된 알카리용매에 쉽게 반응, 붕괴되며 조립질보다 세립질 골재에 더 큰 영향이 나타난다. 골재와 시멘트 사이의 반응에 의하여 K, Na, Ca 및 Si 성분이 함량이 높은 부분으로부터 낮은 곳으로 상호 치환 이동되는데 그 과정에서 smectite와 illite같은 점토광물이 반응생성물로 정출된다. 이러한 광물은 구조물 내에서 수분의 흡수와 방출에 의하여 부피의 팽축이 거듭됨으로써 콘크리트 구조물에 심각한 손상을 야기시킨다.

• Journal of Environmental Impact Assessment
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• v.28 no.4
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• pp.387-399
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• 2019

This research aimed to prepare the classification of the damage types and the damage rating system of noise barriers for expressway noise barriers and to develop deterioration evaluation method of noise barriers by reflecting them. The noise barrier consists of soundproof panels, foundations and posts and the soundproof panels with 10 different types of materials are used in a single or mixed form.In this paper, damage of soundproof panel shows a single or composite damage, and thus a evaluation model of deterioration has been developed for noise barriers that can reflect the characteristic of noise barriers. Materials used mainly for soundproof walls were divided into material types for metal, plastic, timber, transparent and concrete. And damage types for noise barrier were classified into corrosion, discoloration, deformation, spalling and dislocation and damage types were subdivided according to the noise barrier's components and materials. Damage rating was divided into good, minor, normal and severe for each major part of noise barrier to assess damage rating of soundproof panel, foundation and post. The deterioration degree of noise barrier was evaluated comprehensively by using the deterioration evaluation method of whole noise barrier using weighted average. Deterioration evaluation method that can be systematically assessed has been developed for noise barrier using single or mixed soundproof panel and noise barrier with single or complex damage types. Through such an evaluation system, it is deemed that the deterioration status of noise barrier installed can be systematically understood and utilized for efficient maintenance planning and implementation for repair and improvement of noise barriers.

• Journal of Biomedical Engineering Research
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• v.24 no.5
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• pp.427-434
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• 2003

In this paper, we present a speech-based Environmental Control System(ECS) and its application. In the concrete, an ECS using the speech recognition and an portable wheelchair lift control system with the speech synthesis are developed through the simulation and the embodiment. The developed system apply to quadriplegic man and we evaluate the result of physical effect and of mental effect. Speech recognition system is constructed by real time modules using HMM model. For the clinical application of the device, we investigate the result applied to 54-years old quadriplegic man during a week through the questionnaires of Beck Depression Inventory and of Activity Pattern Indicator. Also the motor drive control system of potable wheelchair lift is implemented and the mechanical durability is tested by structural analysis. Speech recognition rate results in over 95% through the experiment. The result of the questionnaires shows higher satisfaction and lower nursing loads. In addition, the depression tendency of the subject were decreased. The potable wheelchair lift shows good fatigue life-cycle as the material supporting the upper wheelchair and shows the centroid mobility of safety. In this paper we present an example of ECS which consists of real-time speech recognition system and potable wheelchair lift. Also the experiments shows needs of the ECS for korean environments. This study will be the base of a commercial use.

• Applied Microscopy
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• v.18 no.2
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• pp.47-58
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• 1988

두가지 쌀 품종(品種) 종자(種子)(S-201, IR-8)의 호분층을 주사(走査) 및 투과(透過) 전자현미경(電子顯微鏡)으로 관찰(觀察)하면 구형(球形)과 결정형(結晶形)의 단백질체(蛋白質體)가 있는 것으로 밝혀졌으며, 구형(球形) 단백질체(蛋白質體)는 세포질내(細胞質內)에 존재(存在)하고 결정형(結晶形) 단백질체(蛋白質體)는 액포내(液胞內)에서 관찰(觀察)되었다. 가상적(假想的)인 한발 스트레스로서 열자극 처리(處理)($40^{\circ}C$ 에서 4시간)는 호분층(糊粉層)내에 단백질체(蛋白質體) 수에서 정상적(正常的)인 대조구보다 $40{\sim}50%$ 감소(減少)되었다. 또한 호분층(糊粉層)에서 단백질체(蛋白質體) 수의 감소(減少)는 IR-8품종(品種)보다 S-201품종(品種)에서 더욱 현저(顯著)하게 관찰(觀察)되었다. 열자극 처리(處理)로서 단백질체(蛋白質體) 수의 감소(減少)는 S-201품종(品種)에서 결정형(結晶形) 단백질체(蛋白質體)를 둘러싸고 있는 tonoplast membrane의 손상(損傷)으로 밝혀졌으며, 이런 손상(損傷)은 IR-8품종(品種)에는 좀 덜하다는 것으로 나타났다. 즉 이것은 S-201품종(品種)이 IR-8품종(品種)보다 열 자극(刺戟)(한발 스트레스)에 더욱 민감(敏感)하다는 것으로 사료된다. 두 품종(品種)의 종자(種子) 내배유(內胚乳)에 녹말(綠末)이 가득찬 주사(走査) 전자현미경(電子顯微鏡) 사진(寫眞)은 녹말(綠末)이 내배유(內胚乳)의 중앙(中央)으로부터 사출(査出)되는 hexagonal rods로 구성(構成)되어 있다는 것을 나타낸다. 이러한 hexagonal rods는 rods부터 쉽게 분쇄될 수 있는 triangular sectors로 구성(構成)되어 있으며, 이 sectors들의 각 내부(內部)는 $2{\sim}8$개의 단위(單位)로 구성(構成)되어 있는 커다란 compound starch grains들이 들어 있다. 이것은 쌀 내배유세포(內胚乳細胞)에서 compound starch drains들의 매우 다양한 크기를 설명(說明)하고 있다.

• Journal of Life Science
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• v.21 no.8
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• pp.1067-1075
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• 2011

Coiled-coil domain-containing protein 98 (CCDC98) plays a role in G2/M DNA damage checkpoint pathways by recruiting breast cancer 1 (BRCA1)-A complex to the DNA-damaged sites. However, the molecular mechanism of CCDC98 on the DNA damage-induced G2/M checkpoint pathways is unclear. In this study, we identifed Wilms tumor 1-associating protein (WTAP) as a novel CCDC98-binding protein, using tandem affinity purification. We confirmed the association between CCDC98 and WTAP using in vivo and in vitro binding assays. We demonstrated that CCDC98 regulates cyclin B1 expression by affecting WTAP protein stability. Based on these results, we suggest that CCDC98 may act as a novel cell cycle regulator by regulating the expression level of cyclin B1.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.4 s.70
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• pp.347-360
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• 2005

The fuel rod instability can be occurred because of the axial and cross flow due to the flow anomaly and/or flow redistribution in the lower core plate region of the pressurized water reactor. The fuel rod vibration due to the hydraulic instability is one of the root causes of fuel failure. The verification on the fuel rod vibration and instability is needed for the new fuel assembly design to verify the fuel rod instability. In this study, the fuel rod vibration and stability analyses were performed to investigate the effect of the grid height, fuel rod support condition, and span adjustment on the fuel rod vibration characteristics for the advanced $16{\times}16$ fuel assembly design. Based on the analysis results, the grid height and grid axial elevation of the advanced $16{\times}16$ fuel assembly design were proposed.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.4
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• pp.299-307
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• 2011

The offshore plants such as FPSO are subjected to combination loading of environmental conditions (swell, wave, wind and current). Therefore the fatigue damage is occurred in the operation time because the units encounter the environmental phenomena and the structural configurations are complicated. This paper is a research for frequency domain fatigue analysis of wide-band random loading focused on accuracy of fatigue damage estimation regarding the proposed methods. We selected ideal bi-modal spectrum. And comparison between time-domain fatigue analysis and frequency-domain fatigue analyses are conducted through the fatigue damage ratio. Fatigue damage ratios according to Vanmarcke's bandwidth parameter are founded for wide-band. Considering safety, we recommend that Jiao-Moan and Tovo-Benasciutti methods are optimal way at the fatigue design for wide-band response. But, it is important that these methods based on frequency-domain unstably change the accuracy according to the material parameter of S-N curve. This study will be background and guidance for the new frequency-domain fatigue analysis development in the future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.2
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• pp.201-206
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• 2011

A spacer grid assembly is one of the most important structural components of the nuclear fuel assembly of a pressurized water reactor (PWR), and it affects the performance of the fuel assembly. The primary design requirement is that the mechanical integrity of the fuel rod should be maintained by the spacer grid assembly during the operation of the reactor. It was known that fretting damage to the fuel rod can be reduced by adjusting the relative moving displacement between the fuel rod and its support. In this study, we used the finite element method to evaluate the characteristics of a sliding support designed to reduce fretting damage of fuel rods.