• Journal of electromagnetic engineering and science
• /
• 제5권1호
• /
• pp.31-35
• /
• 2005

This paper presents low form factor dual polarized antenna incorporating low profile annular ring patch antenna having 90$^{\circ}$ phase delay element for circular polarization(CP) and a reactive-loaded monopole linear polarized(LP) antenna. Both types of receiving antennas operate in the same frequency region from 2.320 GHz to 2.345 GHz, while different polarizations are used to take advantage of polarization diversity. The proposed CP antenna has good broadside radiation patterns, while the LP antenna reveals monopole-like radiation patterns. The gains of the antennas are measured to be 1.93 dBi and 2.24 dBi for CP and LP, respectively.

• Journal of the Optical Society of Korea
• /
• 제15권2호
• /
• pp.152-154
• /
• 2011

We propose a novel method which detects convex and concave corners using radial projection. The sum of two neighbors' differences at the local maxima or minima of the radial projection is compared with the angle threshold for detecting corners. In addition, the use of oriented bounding box trees and partial circles makes it possible to detect the corners of complex shapes. The experimental results show that the proposed method can separately detect the convex and concave corners, and that this method is scale invariant.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.978-980
• /
• 2005

자기 누설 탐상(Magnetic Flux Leakage : MFL) 시스템은 비파괴 검사의 한 방법으로 검사 대상 물체를 적절히 포화시켜 부식이나 결함 부위에서의 누설 자속을 측정하여 결함의 유 무와 크기를 판단하는 방법이다. 대부분 가스관과 가스관을 연결하는 방법으로 용접을 가장 많이 사용하고 있으며 용접부위에서 부식이 가장 많이 발생하고 있다. 용접으로 인해 발생하는 자기 누설신호는 부식신호에 많은 영향을 미친다. 따라서 본 연구는 용접신호가 부식 신호에 미치는 영향을 분석하기 위해 가스관의 용접과 부식과의 거리에 따른 자기누설을 해석하고, 분석하였다. 또한 용접에 의해 왜곡된 부식신호를 보정하고, 판정을 위한 방법을 제시하였다.

• Journal of Oral Medicine and Pain
• /
• 제43권3호
• /
• pp.92-96
• /
• 2018

A 39-year-old male presented with severe pain in right posterior mandibular teeth and temporal area. Initially, the pain in the mandibular teeth was moderate, but the concomitant headache was unbearably severe. His medical history was non-contributory. The clinical and radiographic examination failed to reveal any pathology in the region. There was no tenderness to palpation in the temporalis and masseter muscles or temporomandibular joints. The clinical impression was migraine. The pain in the teeth and headache were aborted using ergotamine tartrate and sumatriptan succinate. Atenolol prevented further pain, while amitriptyline and imipramine had no effect. Migraine can present as non-odontogenic pain in the mandibular teeth, although not as frequently as in the maxillary teeth. A correct diagnosis is essential to avoid unnecessary dental treatments and to manage pain effectively. Clinicians should be able to identify migraine with non-odontogenic dental pain and establish a proper diagnosis through a comprehensive evaluation.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1902-1907
• /
• 2008

The current work presents a design and fabrication technique for a microchannel system to measure the local temperature distribution inside microchannel. This micro channel system fabricated by MEMS technique is integrated with a heater and an array of temperature sensors so that detailed heat transfer phenomena inside micro-scale channel can be studied. Materials widely used in semiconductor process were selected to fabricate a heater and temperature sensors on a silicon wafer. On these heater and sensors a channel wall was fabricated with SU-8. The friction constant and the local Nusselt number distribution measured for the deionized water flow in the microchannel is presented.

• 한국해안해양공학회지
• /
• 제9권4호
• /
• pp.194-200
• /
• 1997

주기적으로 요동하는 외부유동에 의해 생성되는 캐버티 주위의 2차원 천수유동은 수치적으로 연구하였다. 실험결과와 비교하기 위해 T형의 용기모델을 수치적으로 계산하여 만들었다. 수치계산에서는 캐버티의 종횡비가 전체적인 유동패턴에 크게 영향을 끼치지 않고 종횡비 2에서는 캐버티의 깊은 부분에 정체된 유동형태가 생성되는 것을 제시한다. 높은 레이놀즈 수에서 유동을 가시화 시켰을 때 나다나지 않았던 많은 와류들이 유동장을 특성화 시키고 있다. 외부지역에서의 물질전달은 실험에서 나타난 입자궤적과 잘 일치한다. 캐버티의 외부지역에 위치한 두쌍의 와류가 규모가 큰 시계방향과 반시계방향의 순환유동을 발생시키는 원인이 되는 것이 증명된 셈이다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제21권1호
• /
• pp.60-64
• /
• 1999

Recently, for the reconstruction of bony defect and cosmetic improvement, many graft materials and implants have been widely used in the various surgical situations. The alloplastic materials have many advantages such as simplicity of operation, no additional need of surgery, and easy manipulation. The $Medpor^{TM}$(porous high-density polyethylene, Porex Co., USA) was initially studied in 1972 for surgical implant and introduced as an implant material for oral and maxillofacial region by Sauer and King in 1988. This material permits full ingrowth of bone into the implants, substantially increasing the implant's incorporation into the recipient site. It can be shaved during the surgery, which results in an improvement and prefabricated various size and shapes to fit into the surgical defect. The $Medpor^{TM}$ was used in 32 patients from 1995 to 1997 at the maxillofacial region. It was used for paranasal augmentation in 24 cases, for malar augmentation in 2 cases, for infraorbital augmentation in 2 cases, for mandibular angle augmentation in 2 cases, for mandibular body augmentation in 2 cases, for chin vertical augmentation in 1 case. It was mainly fixed with miniplate or screw. There were few complications except one infection and one exposure of the implant.

• ETRI Journal
• /
• 제33권3호
• /
• pp.415-422
• /
• 2011

In this paper, we present a novel vision-based method of recognizing finger actions for use in electronic appliance interfaces. Human skin is first detected by color and consecutive motion information. Then, fingertips are detected by a novel scale-invariant angle detection based on a variable k-cosine. Fingertip tracking is implemented by detected region-based tracking. By analyzing the contour of the tracked fingertip, fingertip parameters, such as position, thickness, and direction, are calculated. Finger actions, such as moving, clicking, and pointing, are recognized by analyzing these fingertip parameters. Experimental results show that the proposed angle detection can correctly detect fingertips, and that the recognized actions can be used for the interface with electronic appliances.

• 대한의용생체공학회:의공학회지
• /
• 제32권2호
• /
• pp.127-133
• /
• 2011

Arteria radialis is a branch of the brachial artery extending down the forearm around the wrist where it closes to skin surface. In the oriental medicine, the skin above arteria radialis has an important role because oriental medicine practitioners put their finger tips on the area, and diagnose patient's health conditions by feeling the pulsation of the arterial contraction. The finger tip diagnostic method relies on subjective decision of the practitioner; and there is a need to develop an objective diagnostic modality. The pulsation of the arterial contraction appears not only a movement on the site but also as temperature fluctuation due to pulsatile feeding of warmer blood. The goal of this study is to demonstrate a feasibility of using an infrared camera quantitatively to detect the temperature fluctuation on the skin. Clinical important three different areas, called chon, gwan, chuk, near a wrist where the arteria radialis reaches close to skin surface are marked with small pieces of surgical tape. A high-speed and high-resolution infrared camera with a 3 cm of field of view measures these areas for 10 second at 200 frames per second with a 320*240 pixel size. The pulsatile temperature fluctuation is calculated after passing a band pass filter to remove any stationary temperature over 10 second. The temperature fluctuation of a healthy male volunteer is measured at a room temperature as a control, and is compared with another measurement performed after 20 minutes staying in a room at a 40 degree Celsius. This comparison is repeated for three times, and indicates that the fluctuation increases after staying 20 minutes in the warm room. This increase becomes smaller when the person stays in the warm room with an acupuncture treatment that decreases body temperature. So that an objective diagnostics on the site may become feasible.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제26권5호
• /
• pp.514-518
• /
• 2000

Chronic osteomyelitis is often considered difficult to treat and may lead to refratory condition in oral and maxillofacial region. Clinical features of chronic osteomyelitis includes pain, swelling, pus discharge, and radiographic change. There are many kinds of treatment of chronic osteomyelitis. One of the most important factors in treating osteomyelitis are removal of infectious foci and administration of massive antibiotics. Recently we reviewed 29 patients with chronic osteomyelitis who visited in our department and treated successfully with our treatment protocols, consisting of surgical intervention and intravenous antibiotics for 2 weeks, and followed by oral antibiotics for 6 weeks. It is concluded that combination of surgical intervention and antibiotic therapy are sufficient to treat the chronic osteomyelitis in oral and maxillofacial region.