• 대한전자공학회논문지TC
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• 제47권7호
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• pp.72-79
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• 2010

셀룰러 네트워크 내에서 cellular 링크와 무선 자원을 공유하는 device-to-device(D2D) 링크는 자신이 속한 셀룰러 네트워크에 심각한 간섭을 줄 가능성이 높기 때문에 그것을 방지하기 위해서는 무선 자원 할당의 최적화가 중요하다. 본 논문에서는 D2D 링크가 자신의 간섭을 최소화하면서 효율적으로 cellular 링크와 공존하기 위해서 subset reuse 방법을 기반으로 하는 자원 할당 기법에 대해 제안한다. Cellular 링크와 D2D 링크 주파수 자원 할당의 효율성을 높이기 위하여 셀 상황에 따라 가변적인 subset 크기를 가지는 group-wise subset reuse 방법을 제안한다. 또한, cellular 링크가 같은 주파수 대역을 사용하는 D2D 전송에 의해 간섭을 받는 경우, D2D 링크의 power를 최적화하여 cellular 링크로의 간섭을 최소화하게 된다. 컴퓨터 시뮬레이션 결과를 통하여 link SINR에서 성능 이득을 가지며, local traffic이 증가할수록 전체 cell throughput이 높아짐을 보였다.

• 한국운동역학회지
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• 제25권3호
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• pp.353-361
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• 2015

Objective : The aim of this study was to develop the non-powered horse riding device and was to evaluate the elaborate its applicability throughout static structural and transient structural analysis of the outdoor core strength exercise equipment. Method : Fifteen college students (mass: $69.55{\pm}13.38kg$, height: $1.69{\pm}5.61m$, age: $21.42{\pm}1.83yrs$) rode the powered horse riding device and 14 college students (mass: $71.12{\pm}9.74kg$, height: $1.73{\pm}3.31m$, age: $22.50{\pm}1.47yrs$) rode the non-powered horse riding device for the comparison. All motion capture data was collected at 100 Hz using six infrared cameras and the muscular activities were collected using a Delsys Trigno wireless system. The peak forward/backward lean angle, range of motion anter/posterior and vertical COM(Center of mass) movement of trunk and pelvis segment, and muscle activities of six muscles were compared between the two devices by using independent t-test (p<.05). Results : Several kinematic variables (peak forward-backward lean angle and vertical COM movement of trunk and pelvis segment, range of motion of trunk) significantly different between non-powered and powered horse riding device. The muscle activities of Rectus abdominis and External oblique of abdomen on the non-powered horse riding device were significantly greater than those of the powered device. Conclusion : It was concluded that non-power horse riding device could give the effect of core strength exercise as well as the body motion which can simulate the powered horse riding device.

• Design & Manufacturing
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• 제16권4호
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• pp.52-59
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• 2022

Currently, Korea is an aging society and is expected to become a super-aged society in about four years. X-ray devices are widely used for early diagnosis in hospitals, and many X-ray technologies are being developed. The development of X-ray device technology is important, but it is also important to increase the reliability of the device through accurate data management. Sensor nodes such as temperature, voltage, and current of the diagnosis device may malfunction or transmit inaccurate data due to various causes such as failure or power outage. Therefore, in this study, the temperature, tube voltage, and tube current data related to each sensor and detection circuit of the diagnostic X-ray imaging device were measured and analyzed. Based on QC data, device failure prediction and diagnosis algorithms were designed and performed. The fault diagnosis algorithm can configure a simulator capable of setting user parameter values, displaying sensor output graphs, and displaying signs of sensor abnormalities, and can check the detection results when each sensor is operating normally and when the sensor is abnormal. It is judged that efficient device management and diagnosis is possible because it monitors abnormal data values (temperature, voltage, current) in real time and automatically diagnoses failures by feeding back the abnormal values detected at each stage. Although this algorithm cannot predict all failures related to temperature, voltage, and current of diagnostic X-ray imaging devices, it can detect temperature rise, bouncing values, device physical limits, input/output values, and radiation-related anomalies. exposure. If a value exceeding the maximum variation value of each data occurs, it is judged that it will be possible to check and respond in preparation for device failure. If a device's sensor fails, unexpected accidents may occur, increasing costs and risks, and regular maintenance cannot cope with all errors or failures. Therefore, since real-time maintenance through continuous data monitoring is possible, reliability improvement, maintenance cost reduction, and efficient management of equipment are expected to be possible.

• Journal of Cardiovascular Imaging
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• 제31권4호
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• pp.180-187
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• 2023

BACKGROUND: Two-dimensional (2D) transesophageal echocardiography (TEE) is commonly used for assessing patients undergoing transcatheter atrial septal defect (ASD) device closure. 3D TEE, albeit providing high resolution en-face images of ASD, is used in only a fraction of cases. We aimed to perform a comparative analysis between 3D and 2D TEE assessment for ASD device planning. METHODS: This was a prospective, observational study conducted over a period of one year. Patients deemed suitable for device closure underwent 2D and 3D TEE at baseline. Defect characteristics, assessed separately in both modalities, were compared. Using regression analysis, we aimed to derive an equation for predicting device size using 3D TEE parameters. RESULTS: Thirty patients were included in the study, majority being females (83%). The mean age of the study population was 40.5 ± 12.05 years. Chest pain, dyspnea and palpitations were the common presenting complaints. All patients had suitable rims on 2D TEE. A good agreement was noted between 2D and 3D TEE for measured ASD diameters. 3D TEE showed that majority of defects were circular in shape (60%). The final device size used had high degree of correlation with 3D defect area and circumference. An equation was devised to predict device size using 3D defect area and circumference. The mean device size obtained from the equation was similar to the actual device size used in the study population (p = 0.31). CONCLUSIONS: Device sizing based on 3D TEE parameters alone is equally effective for transcatheter ASD closure as compared to 2D TEE.

• 한국해양공학회지
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• 제26권3호
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• pp.1-5
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• 2012

A complex energy saving device has been developed for middle class vessels. The propulsive performance of the developed device is described through a model test. The pre-swirl stator, which recovers the rotational energy of the propeller slipstream, is a well-known energy saving device for large vessels. The pre-swirl stator for a large vessel is usually cast as a part of the stern frame and has a high cost. The manufacture of a cast stator for an existing vessel is almost impossible. The complex device that was developed can be fitted on astern frame by welding. The model tests show a 4-6% efficiency gain for middle class vessels with the developed appendages compared to those with bare hulls.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1024-1026
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• 2004

We have developed the five mask $PMOS^1$ and the six mask CMOS process architecture for poly-Si TFT. In order to have a competitive process with that for a-Si TFT, the simple co-planar electrode structure whose data line electrode and pixel electrode are on the same plane was adopted. In addition, RGB + White four color $technology^2$ were applied to achieve high aperture ratio and transmittance. Using the aforementioned process architecture and four color technology, 2.0 inch qCIF transmissive micro-reflectance (TMR) device was successfully fabricated.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권9호
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• pp.400-406
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• 2003

Efficient electrodes are devised for organic luminescent device(OLED). ITO electrode is treated with $O_2$ plasma. In order to inject hole efficiently, there is proposed the shape of anode that inserted plasma polymerized films as buffer layer between anode and organic layer using thiophene monomer. In the case of device inserted the buffer layer by using the plasma polymerization after $O_2$ plasma processing for ITO transparent electrode, since it forms the stable interface and reduce the moving speed of hole, the recombination of hole and electronic are made in the emitting layer. Therefore it realized the device capability of two times in the aspect of luminous efficiency than the device which do not be inserted the buffer layer. Experiments are limited to the device that has the structure of TPD/$AIq_3$, however, the aforementioned electrodes can similarly applied to the organic luminous device and the Polymer luminous device.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.970-973
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• 1999

When the size of the device is decreased, the hot carrier degradation presents a severe problem for long-term device reliability. In this paper we fabricated & tested the 0.26${\mu}{\textrm}{m}$ NMOSFET with wet gate oxide and nitride oxide gate to compare that the characteristics of hot carrier effect, charge to breakdown, transistor Id_Vg curve and charge trapping using the Hp4145 device tester As a result we find that the characteristics of nitride oxide gate device better than wet gate oxide device, especially a hot carrier lifetime(nitride oxide gate device satisfied 30years, but the lifetime of wet gate oxide was only 0.1year), variation of Vg, charge to breakdown and charge trapping etc.

• 전기전자학회논문지
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• 제7권1호
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• pp.1-8
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• 2003

본 논문에서는 고내압 및 고속 스위칭 특성을 갖는 고성능 BCD(Bipolar- CMOS-DMOS) 소자 구조를 고안하였다. 공정 및 소자 시뮬레이션을 통하여, 최적화된 공정 규격과 소자 규격을 설계하였으며, 고안된 소자의 전기적 특성을 만족시키기 위하여 이중 매몰층 구조, 트랜치 격리 공정, n-/p- 드리프트 영역 형성기술 및 얕은 접합 깊이 형성기술 등을 채택하였다. 이 스마트 파워 IC는 20V급 Bipolar npn/pnp 소자, 60V급 LDMOS소자, 수 암페어급의 VDMOS, 20V급 CMOS소자 그리고 5V급 논리 CMOS를 내장하고 있다.

• Journal of Biosystems Engineering
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• 제22권4호
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• pp.401-410
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• 1997

Scattering of seeds is one of the problems in the hill- dropping planters with a roller-type metering device. For crops like rice, corns and beans, the hill-dropping is own better for a high yield than the drill planting. The roller type metering device has been used for the drill planters and has many advantages. However, it has a problem of scattering of seeds when they are placed on rows. In this study a method was developed to design the roller type metering device fir the precision hill-droppings. Design parameters were derived to configure completely the geometries of the roller and brush. The method was applied to the design of the metering device of the rice seeding machines. The field test showed that the metering device designed by the method made a better performance of seed placement than that made by the precvious one. The method also can be applied to the design of metering devices for the precise hill-droppings of other crops.