• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.8
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• pp.791-796
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• 2012

Small gas turbine engines are used in aircraft as an auxiliary power unit (APU) to supply compressed air to start the main engine and for emergency electricity. When an aircraft is operating in an environment in which sand and dust is present in the ambient air, the engines as well as the APU ingest the sand and dust. This causes erosion of the engine and a degradation in its performance. The present study investigated the effect of sand and dust ingestion on small gas turbine engines. The concentration of sand and dust was $4.4{\times}10^{-5}kg$ per unit kg of air, which follows the specification in MIL-E-8593. The test was conducted for 10 h, and the engine performance before and after the test was compared. In addition, a tear-down inspection was conducted to examine the erosion patterns of sub-components such as the impeller and turbine wheel.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.357-362
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• 1997

In vivo testings of the monoleaflet polymer valve were performed in seven dogs to prove its blood biocompatibility. The monoleaflet polymer valve used in this study was developed for short-term usage n the ventricular assist device. The frame and leaflet of the polymer valve were made of polyurethane. The inter-aortic valved conduit were implanted in four dogs and the ventriculo-atrial valved conduit was implanted in one dog. The ventricular assist devices with polymer valve were implanted in two dogs. The longest survival was 20 days. Main causes of death were bleeding and infection. To examine the blood compatibility, each blood sample was collected and RBC, WBC, hematocrit, hemoglobin, platelet and lactic acid dehydrogenase were analyzed. These studies thus far demonstrated that, with further development, a reliable and inexpensive polymer valve will be used in the ventricular assist device as short term usage.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.211-218
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• 2021

A recent spread of personal mobility devices such as electric kickboards has brought about a rapid increase in accident cases. Such vehicles are susceptible to falling accidents due to their low dynamic stability and lack of outer protection chassis. This paper presents the development of an automatic emergency braking system and a safe starting system as driving assistance devices for electric kickboards. The braking system employed artificial intelligence to detect nearby threaening objects. The starting system was developed to disable powder to the motor until when the driver's boarding is confirmed. This study is meaningful in that it proposes the convergence technology of advanced driver assistance systems specialized for personal mobility devices.

• Membrane Journal
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• v.15 no.3
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• pp.224-232
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• 2005

The use of the lung assist device (LAD) would be well suited for acute respiratory failure (ARF) patients, combining the simplicity of mechanical ventilation with the ability of extracoporeal membrane oxygenators (ECMO) to provide temporary relief for the natural lungs. This study's specific attention was focused on the effect of membrane vibration in the LAD. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on blood hemolysis. We tried to decide upon excited frequency band of limit hemolysis when blood hemolysis came to through a membrane vibration action. The excited frequency of the module type 5, consisted of 675 hollow fiber membranes, showed the maximum gas transfer rate. We concluded that the maximum oxygen transfer rate seemed to be caused by the occurrence of maximum amplitude and the transfer of vibration to hollow fiber membranes. It was excited up to $25{\pm}5$ Hz at each blood flow rate of module type 5. We found that this frequency became the 2nd mode resonance riequency of the flexible in blood flow. Blood hemolysis was low at the excited frequency of $25{\pm}5$ Hz. Therefore, we decided that limit hemolysis frequency of this LAD was $25{\pm}5$ Hz.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.376-378
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• 2012

중앙 처리장치, 주기억장치, 보조기억장치로 이어지는 현재의 컴퓨터 구조에서 비휘발성 메모리 소자의 발전으로 주기억장치를 비휘발성 메모리 소자로 대체하는 컴퓨터 시스템의 변화가 요구되고 있다. 이런 흐름에 맞춰 주기억장치에 기반한 새로운 파일시스템을 제시한다. 또한 새롭게 제시된 파일시스템과 유사한 tmpfs를 이용하여 기존의 시스템에 쓰이던 ext4fs와 비교하여 성능의 향상을 확인한다.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.141-144
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• 2000

일반인들은 음성인식을 이용한 생활보조기구들의 필요성이 적지만 장애인이나 노인들은 가족이나 주변인의 도움을 받지 않고서는 가전제품의 작동이나 전화통화 등과 같은 일을 스스로 하기에는 쉽지 않다. 이러한 사람들에게 각 가정에 널리 보급되어 있는 PC를 이용하여서 타인의 도움을 받지 않고서도 간편하게 사용할 수 있게 음성을 이용한 생활보조기구들 제어에 응용하였다본 음성인식기는 음성의 끝점 검출, 음성의 특징계수 추출, 백터 양자화 학습 및 인식, HMM학습 그리고 HMM인식으로 나누어져 있다. 그리고 그 인식 결과에 따라 생활보조기구등을 제어하였다. 이러한 음성인식기를 만드는 것은 노인이나 장애인들에게 자신이 혼자할수 없는 생활의 편리함을가져다 주기 위함이고 일반정상인에게도 많은 편리함을 가져다 주기 위함이다. 그러나 언어 학습과정에서 노인이나 환자는 학습에 어려움이 있어 적은 학습으로도 인식되어야하는 과제가 남아있다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.814-817
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• 2004

It is a challenging task to make the paraplegic to walk with out the assist of the caregiver. So, we have developed various type of gait orthosis for paraplegic during the five years lately. The purpose of this study ultimately is energy consumption test of serveral type gait orthosis for developing the high efficiency gait orthosis. From the experimental results, the oxygen consumption rate were 6.9$\pm$3.3ml/kg in RGO gait, 5.3$\pm$1.3ml/kg in PGO, and 6.2$\pm$3ml/kg in HGO gait. The maximum hip flexion angle were 16$^{\circ}$ in RGO , 15$^{\circ}$ in PGO, and 47.5$^{\circ}$. in HGO. As a result It was found that. Hybrid Gait Orthosis need high energy consumption more than PGO for walking, but it is small weight and strengthened muscle.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2105-2107
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• 2002

Geometry PIG 시스템은 배관의 상태 및 이상유무를 검사하여 그 결과를 저장하는 시스템으로 항법장치를 내장하고 있어 배관의 위치를 추정할 수 있다. PIG의 위치결정을 위해 후처리 보조 항법 알고리듬으로 비선형 스무딩 필터를 적용하고. 필터 측정치로 GPS를 이용한 위치기준점의 위치정보와 속도계를 이용한 속도정보를 사용하고, 특히 본 논문에서는 이들 정보 외에 Weld detector를 이용한 직선이동거리정보를 이용한 후처리 보조 항법 알고리듬을 PIG 시스템에 적용한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.853-856
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• 2017

우리나라에 장애인 인구의 10% 정도인 약 25만 명의 사람들이 살아가고 있다[3]. 그러한 분들을 위한 여러 복지와 편의시설이 만들어지고 있지만 아직 도로를 안전하게 다니기에는 미흡한 부분이 많다. 시각장애인들이 좀 더 안전하게 생활을 할 수 있도록 하는 보조 장치를 제안한다. 사용자가 필요한 순간의 모습을 촬영한 뒤 딥 러닝으로 축적된 학습데이터를 이용하여 그 장면을 분석한다. 그 결과를 하나의 문장으로 표현하여 이어폰을 통해 사용자에게 서비스를 제공한다. 지원된 음성 서비스를 통해 시각장애인들이 걸어가는 길에 어떠한 장애물이 있는지 알려주어 위험한 상황에 놓이지 않고 안전하게 길을 걸어 다닐 수 있도록 보조해준다.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.199-205
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• 2007

Most of information and communication assistance machinery and tools for disorder people of Occupied are machinery and tools for a visual impairment person and software, The things which can apply to only a specification disorder type and a specification disorder part are most, A special keyboard or a special mouse device of the handicapped person that disorder rank is comparatively the hardness makes the mainstream. It is reported in diffusion rate being very low if I compare this with total disorder population. I study new 1 plan which it can be applied to various disorder types and disorder parts through an intelligent special input device in a study of a book and, I designed this at the real standard that I could manufacture and incarnated it. In addition, I suggested this in a base for a design of a universal supporting input device and suggestion for the side of incarnation plan and a future study direction.