• International Journal of Aeronautical and Space Sciences
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• 제8권2호
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• pp.121-125
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• 2007

In late 1960's, engineers of the engine manufacturer experienced that the distortion of inlet flow of turbofan and turbojet engine could cause the surge in compressor and affect overall engine operational performance, which result in the deterioration of stability of the engine. In this study, block type of inlet distortion simulating device has been developed in order to investigate the effect of inlet distortion on the deterioration of overall engine operational performance. The inlet distortion simulating device was installed in front of engine inlet in order to simulate distortion of inlet flow. The degree of inlet distortion was measured by rakes installed upstream the inlet distortion simulating device and between the engine inlet and inlet distortion simulating device. Before applying the inlet distortion simulating device to real engine, preliminary tests were performed with a simulated engine in order to verify the degree of inlet distortion by the device. Preliminary inlet distortion tests were performed in Altitude Engine Test Facility(AETF) of Korea Aerospace Research Institute(KARI) and results showed that the inlet distortion simulating device could be used in simulating various inlet distortion cases.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권2호
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• pp.102-110
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• 2002

In this paper, we present the fabrication of tunable capacitors and 3-dimensional inductors. This work was related to fabricated 3-dimensional device for need of micro device in developing new intelligence age. This device was fabricated by electroplating used electroplating PR and high-vacuum evaporation of metal. Fabricated micro-inductor is consisted of air-bridge on electroplating rod and electroplated core. Micro-capacitor is consisted of thin metal membrane and electroplated core. Electroplating material is used Cu metal solvent. Air-gap between metal-layers function as almost perfect isolation layer. The most advantage of our micro-inductor and micro-capacitor compared to present device is a possibility that can fabricate on RF MEMS(microelectro-mechanical systems) application with high performance and various function. In this paper, we present the fabrication of tunable capacitors and 3-dimensional inductors. This work was related to fabricated 3-dimensional device for need of micro-device in developing new intelligence age. This device was fabricated by electroplating used electroplating PR and high-vacuum evaporation of metal. Fabricated micro-inductor is consisted of air-bridge on electroplating rod and electroplated core. Micro-capacitor is consisted of thin metal membrane and electroplated core. Electroplating material is used Cu metal solvent. Air-gap between metal-layers function as almost perfect isolation layer. The most advantage of our micro-inductor and micro-capacitor compared to present device is a possibility that can fabricate on RF MEMS application with high performance and various functions.

• Journal of Biosystems Engineering
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• 제38권3호
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• pp.215-221
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• 2013

Purpose: Opuntia Humifusa has been used in the food and beauty industry after removing spines and glochids clearly. This study compared the methods used in removing spines and analyzed the design factors for developing a spine removal device. Method: This study compared the spine removal ratios in accordance with the length of brush, water spray pressure, the number of water spray, and the size of Opuntia Humifusa in a rotating brush device and a water spray device. In addition, this study compared the reversal ratios according to the inclination angle of a conveyor, the drop height of Opuntia Humifusa, and the speed of the conveyor to analyze the reversal factors. Results: The spines were not removed clearly in the rotating brush method, and the glochids were nailed deeply. The spine removal ratio was 96.9% with the water spray pressure of 20 $kgf/cm^2$ and the conveyor speed of 10 cm/s in the water spray method. The number of water spray was correlated with the spine removal ratio, and the average spine removal ratio was 95.6% with three cycles of water spray. The reversal ratio was 97% with the inclination angle of the conveyor $20^{\circ}$, the drop height of 380 mm, and the conveyor speed of 10 cm/s. Conclusions: In order to develop a Opuntia humifusa spine removing device, this study compared the rotating brush and water spray methods. As a result, each spine removal performance of the rotating brush and water spray methods was 96.9% and 95.6%, respectively. Although the performance of the rotating brush method was slightly higher than that of the water spray method, the water spray method was suitable for removing spines from stem because the epidermis of stem was damaged and the glochids were nail deeply in the rotating brush method. Further studies on appropriate arrangement of spray nozzles, maintaining the optimal water spray pressure, the speed and angle control of the feeding conveyor, and devices for inducing the stem to the center will be needed in combining the water spray device and the reversal device.

• 디지털융복합연구
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• 제14권11호
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• pp.501-505
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• 2016

최근 들어, 스마트 단말에서 지불, 인터넷 뱅킹 등 금융업무와 관련된 중요한 정보들을 다루는 경우가 많아졌다. 또한 스마트 단말의 실행환경이 공개 소프트웨어 환경 위주로 발전하면서, 사용자들이 임의의 응용소프트웨어를 다운받아 사용하는 것이 용이하게 됨에 따라, 스마트 단말이 보안적 측면에서 취약하게 되었다. 본 논문에서는 하드웨어 기반의 스마트 단말 보안 기술의 특징을 알아본다. 또한, 본 논문에서는 스마트 단말 에서 실행되는 응용프로그램을 위한 MTM 하드웨어기반의 안전한 스마트 단말 실행환경에 대한 구현방법을 제안한다. 기존의 MTM 이 모바일 장치에 대한 신뢰의 근원 기능만을 제공한 반면, 본 논문에서 제시하는 MTM 기반 모바일 보안 환경은 모바일 장치에서 실행되는 응용프로그램이 필요로 하는 다양한 보안 기능을 제공할 수 있다. 향후, 보안 하드웨어와 연동이 가능한 IoT 기기와 게이트웨이 보안 기술, 그리고 보안 하드웨어를 활용하여 다양한 IoT 기기에 적용하여 신뢰성과 보안성을 확보하는 방안에 대한 연구를 진행할 예정이다.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.107-114
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• 2011

Two-step thermochemical cycle using ferrite-oxide($Fe_3O_4$) device was investigated. The $H_2O$(g) was converted into $H_2$ in the first experiment which was performed using a dish type solar thermal system. However the experiment was lasted only for 2 cycles because the metal oxide device was sintered and broken down. Another problem was that the reaction was taken place mainly on a side of the metal oxide device. The $m-ZrO_2$, which was widely known as a material preventing sintering, was applied on the metal oxide device. The ferrite loading rate and the thickness of the metal oxide device were increased from 10.67wt% to 20wt% and from 10mm to 15mm, respectively. The chemical reactor having two inlets was designed in order to supply the reactants uniformly to the metal oxide device. The second-experiment was lasted for 5 cycles, which was for 6 hours. The total amount of the $H_2$ production was 861.30mL.

• 중소기업융합학회논문지
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• 제5권2호
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• pp.15-20
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• 2015

최근 스마트폰 기술이 발달함에 따라 웨어러블 기기의 발전 속도도 빨라지고 있다. 그러나, 웨어러블 기기는 소형으로 제작되어 사용되기 때문에 작은 전력으로 오랫동안 동작되게 하는 것이 필요하다. 본 논문에서는 웨어러블 기기 사용 편리성을 극대화하기 위해서 소형화된 웨어러블 기기에 적합한 효율적인 리듐 폴리머 배터리 모델을 설계 및 구현한다. 제안된 모델은 열전소자를 응용하여 배터리 크기를 소형화하고 배터리 용량을 경량화한 한 것이 특징이다. 또한, 제안 모델은 Peltier device의 특성을 이용하여 사람의 체온과 상온의 온도 차를 이용하여 전력을 발생시켜 충전을 하는 방식을 사용하기 때문에 웨어러블 기기의 사용 시간을 대폭 향상 시켜준다. 특히, 제안 모델은 웨어러블 기기뿐만 아니라 스마트폰의 보조 충전용으로도 사용 가능한다.

• 대한인간공학회지
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• 제35권6호
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• pp.519-533
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• 2016

Objective: This study lays its aims at the definition of relevant operation method and function by researching on the value to be brought when applying smart device that can hand carry soft and flexible materials like jelly. Background: New technology and material play a role in bringing type transformation of interface and change of operation system. Recently, importance has been increased on the study of Organic User Interface (OUI) that conducts research on the value of new method of input and output adopting soft and flexible materials for various instruments. Method: For fulfillment of the study, 27 kinds of gestures have been defined that are usable in handheld device based on existing studies. Quantitative research of survey was conducted of adult male and female of 20s through 30s and an analysis was done on the function that can be linked to gestures with highest level of satisfaction. In order to analyze needs and hurdles of users for the defined gesture, a focus group interview was conducted aiming at the groups of early adopters and ordinary users. Results: As a result, it was found that users have much value regarding usability and fun for elastic device and analysis could be conducted on preferred gesture and its linkable functions. Conclusion: What is most significant with this study is that it sheds new light on the values of a device made of elastic material. Beyond finding and defining the gestures and functions that can be applied to a handheld elastic device, the present study identified the value elements of an elastic device - 'usability and 'fun' -, which users can basically desire from using it. Application: The data that this study brought forth through preference and satisfaction test with the gestures and associated functions will help commercialize an elastic device in future.

• 스마트미디어저널
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• 제7권2호
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• pp.15-22
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• 2018

동공 추적 기술은 스마트 장치와 연계하여 사용자에게 편의를 제공할 수 있는 효율적인 정보 제공 수단으로 사용될 수 있다. 본 논문에서는 Pupil-labs에서 제작한 모바일 동공 추적 장치를 사용하여 사용자의 응시점 거리를 측정하고, 정확도와 정밀도를 분석하는 실험 수행결과를 보인다. 이를 기반으로 동공 추적 장치가 측정하는 동공의 응시점 위치와 대상 타겟과의 오차를 비교한다. 모바일 동공 추적 장치도 한 종류의 카메라이기 때문에 사용하기 전에는 반드시 캘리브레이션 작업을 수행해야 한다. 일반적으로 사용하는 2차원 캘리브레이션 방법뿐만 아니라, 3차원 캘리브레이션 수행 방법에 대해 설명한다. 3차원 캘리브레이션은 2차원 캘리브레이션 결과보다 높은 정확도를 갖기 위해임의의 평면을 설정하여 다양한 3차원 공간상에서 캘리브레이션을 수행하는 과정을 의미한다. 3차원 캘리브레이션의 효율성을 보이기 위해 실험결과에 대한 분석 결과를 설명한다. 또한 전반적인 장치의 사용 방법과 장치를 통해 얻을 수 있는 다양한 정보를 소개한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.891-892
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• 2016

최근 스마트 홈은 기기 간 관계를 맺어 작업을 동작시키는 연구가 진행되고 있다. 그러나 기존 시스템은 기기가 동작하고 있을 경우 타 기기의 작업이 실행되면 간섭이 발생하여 작업의 효율이 저하될 수 있는 문제점이 있다. 본 논문에서는 이러한 문제점을 해결하기 위해 사용자 기기 선택에 따른 우선순위 자동 설정 알고리즘을 설계하였다. 사용자는 어플리케이션을 통하여 사용할 기기를 선택하고 기기 간 선택 여부를 비교하여 작업 안에서의 우선순위를 설정한다. 이를 통해 사용자가 원하는 기기만으로 작업 환경을 구성할 수 있으며 작업 진행 중 선택되지 않은 타 기기의 간섭이 줄어들기 때문에 효율적인 작업능률을 기대할 수 있을 것으로 사료된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1559-1564
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• 2003

In this paper, a control method is presented to improve performance of haptic display on a passive haptic device equipped with passive actuators. In displaying a virtual wall with the passive haptic device, an unstable behavior occurs with excessive actions of brakes due to the time delay mainly arising from the update rate of the virtual environment and force approximation originated from the characteristics of the passive actuators. The previous T.D.P.C. (Time Domain Passivity Control) method was not suitable for the passive haptic device, since a programmable damper used in the previously introduced T.D.P.C. method easily leads to undesirable behaviors. A new passivity control method is evaluated with considering characteristics of the passive device. First, we propose a control method which is designed under the analysis of the passive FME (Force Manipulability Ellipsoid). And then a passivity control scheme is applied to the proposed control method. Various experiments have been conducted to verify the proposed method with a 2-link mechanism.