• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.7 s.361
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• pp.105-111
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• 2007

In this paper, we designed and fabricated a 3-dB tandem coupler using air-bridge technology for millimeter-wane monolithic integrated circuits, operating at W-band($75{\sim}110\;GHz$) frequency. Tightly edge-coupled CPW line has low directivity due to different even-mode and odd-mode phase velocity. To overcome this disadvantage, a 3-dB tandem coupler which comprises the two-sectional weakly parallel-coupled lines with equal phase velocity was designed at W-band. The proposed coupler was fabricated using air-bridge technology to monolithically materialize the uniplanar coupler structure instead of conventional multilayer or wire bonded structure. From the measurements, the coupling coefficient of $2.9{\sim}3.6\;dB$ and the good phase difference of $91.2{\pm}2.9^{\circ}$ were obtained in broad frequency range of $75{\sim}100\;GHz$.

• Bulletin of the Korean Chemical Society
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• v.21 no.1
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• pp.37-38
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• 2000

• Bulletin of the Korean Chemical Society
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• v.17 no.8
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• pp.671-673
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• 1996

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.286-292
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• 1995

국내 최초의 한국표준원전 가압경수로인 울진 3,4 호기의 운전 특성을 정확하게 실시간으로 모사할 수 있는 한국표준원전 NPA가 개발되고 있다. 동 NPA는 발전소의 정상 및 비정상 운전 상태를 Desk-top 소령 컴퓨터에서 모사하여 그 결과를 그림화면(mimic)에 나타내고 운전원 조치 사항을 Interactive하게 수용할 수 있는 능력을 갖추고 있다. 한국표준원전 NPA의 개발을 위하여 울진 3,4 호기 한국표준원전의 설계 자료를 기준으로 그래픽사용자 인터레이스의 새로운 mimic 및 해석모델에서 사용하는 데이타베이스를 성공적으로 작성하였다. 향후 한국표준원전 NPA는 새로운 모형 개발을 완료한 후 발전소 운전자료와의 비교분석을 통해 성능 검증을 거치면 교육을 및 엔지니어링 작업에 유용하게 사용될 수 있을 것이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2626-2631
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• 2011

CST(C-shape sharp turn) represented the motion whereby fish bend their tail quickly in a C-shape to achieve an emergent changing of its swimming direction on fish swimming. But there is not yet the general motion trajectory functions related to CST. In this paper, we proposed the very simple motion functions related to CST sequence recorded from a real fish by biologists. Through the computer simulations, we confirmed the usefulness of the proposed function.

• The Korean Journal of Pain
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• v.23 no.3
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• pp.202-206
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• 2010

Magnetic resonance image (MRI) is the most sensitive imaging test of the spine in routine clinical practice. Unlike conventional x-ray examinations and computed tomography scans, high-quality magnetic resonance images can be assured only if patients are able to remain perfectly still. However, some patients find it uncomfortable to remain still because of pain. In that condition, interlaminar cervical epidural injections can reduce pain and allow the procedure. When using air with the "loss of resistance" technique in epidural injections to identify the epidural space, there is the possibility of injected excessive air epidurally to mimic a herniated disc. We describe a case report of epidural air artifact in a cervical MRI after cervical epidural injections.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.585-592
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• 1999

A new paradigm of technology, based on the overall interactions of technology, human and environment, is explored. History of technology and machines is reviewed in terms of the interactions of human and machines. Two main concepts of intelligent interactions proposed, holism and embodiment, are based on the interactions of machines and human through human body : Korperlichkeit ( corporeality). Human body movements are the result of long periods of evolution and, thus, are very optimized motions. Complicated and flexible motions could be easily achieved by mimicking human body movements. Motion capture and mimic systems based on the electromagnetic, visual, and gyroscopic type trackers, are being implemented to demonstrate these concepts. Also, various motion mappings are investigated on these interactive systems. By exploring a new paradigm of technology through Korperlichkeit, an oriental view of technology as relativities may evolve to embrace the limitations of western view of machines as an absolute independent form.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.151-154
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• 1999

In this paper, we showed parasitic effects in the millimeter wave package, and proposed a suppression method of parasitic effects using Si lossy layer. From CB-CPW used as a transmission line of the MIMIC package, PPL mode is generated and this causes the parasitic effects considered from this paper. Parasitic effects caused by PPL mode such as resonance, radiation, and crosstalk in the single and multi-chip package ran affect to the performance of MIMIC seriously. To suppress these parasitic effects, we adapted Si lossy layer $\rho$ . The PPL mode can be suppressed by the lossy layer, and it eliminates the parasitic effects. It is expected that showed results ran be used as luxurious data for design MIMICs and various types of millimeter wave applications.

• Journal of Korean Neurosurgical Society
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• v.59 no.4
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• pp.410-413
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• 2016

Lumbar radiculopathy is generally caused by such well-recognized entity as lumbar disc herniation in neurosurgical practice; however rare pathologies such as thrombosed epidural varix may mimic them by causing radicular symptoms. In this case report, we present a 26-year-old man with the complaint of back and right leg pain who was operated for right L4-5 disc herniation. The lesion interpreted as an extruded disc herniation preoperatively was found to be a thrombosed epidural varix compressing the nerve root preoperatively. The nerve root was decompressed by shrinking the lesion with bipolar thermocoagulation and excision. The patient's complaints disappeared in the postoperative period. Thrombosed lumbar epidural varices may mimic lumbar disc herniations both radiologically and clinically. Therefore, must be kept in mind in the differential diagnosis of lumbar disc herniations. Microsurgical techniques are mandatory for the treatment of these pathologies and decompression with thermocoagulation and excision is an efficient method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.243-247
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• 1996

A general procedure for motion capture and mimic system has been delineated. Utilizing sensors operated in the magnetic fields, complicated and optimized movements are easily digitized to analyze and reproduce. The system consists of a motion capture module, a motion visualization module, a motion plan module, a motion mimic module, and a GUI module. Design concepts of the system are modular, open, and user friendly to ensure the overall system performance. This procedure is being implemented on a virtual cyber cube. and an inverted pendulum. With modifications, this procedure can applied for complicated motion controls.