• 한국임상수의학회지
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• 제16권2호
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• pp.469-473
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• 1999

A 120 kg, 3-year-old, male ostrich (Struthio camelus) was submitted to the veterinary teaching hospital, Chonbuk national university, for chronic weight loss, anorexia, small hard fecal pellets, and lethargy. Illness was first noticed approximately 2 weeks before submission. Although the bird was able to stand, he was extremely weak and cachectic. Blood examination indicated that the bird was dehydration (PCV: 55%). Fluoroscopic and lateral abdominal radio-graphic view indicated impaction of distended proventriculus with bigger rocks than normal. Anesthesia was induced with ketamine (10 mg/kg, IV)-xylazine (1 mg/kg, IV) combination and maintained with ketamine (10 mg/kg, IV) at intervals of 8 to 15 minutes during the entire procedure. After induction of general anesthesia, the bird was positioned in dorsal recumbency. The skin was incised approximately 15cm caudal to the caudal margin of the sternum and extended 20 to 25 cm caudally. After the proventriculotomy was peformed, the impacted material that weighed 3kg contained rocks in 4 to 6cm diameter was removed. The incision of proventriculus was closed in 2 layers. Cephalothin sodium (30 mg/kg, IV, q12hrs) and dexamethazone (2 mg/kg, IM, q24hrs) was administered before and after 5 days of the operation. The bird was eating well and defecating normal feces after 3 weeks of the surgery

• 대한기계학회논문집A
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• 제30권8호
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• pp.993-1000
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• 2006

Operating experience of steam generators has shown that cracks of various morphology frequently occur in the steam generator tubes. These cracked tubes can stay in service if it is proved that the tubes have sufficient safety margin to preclude the risk of burst and leak. Therefore, integrity assessment using exact limit load solutions is very important for safe operation of the steam generators. This paper provides global and local limit load solutions for surface cracks in the steam generator tubes. Such solutions are developed based on three-dimensional (3-D) finite element analyses assuming elastic-perfectly plastic material behavior. For the crack location, both axial and circumferential surface cracks, and for each case, both external and internal cracks are considered. The resulting global and local limit load solutions are given in polynomial forms, and thus can be simply used in practical integrity assessment of the steam generator tubes.

• Archives of Plastic Surgery
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• 제43권5호
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• pp.446-450
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• 2016

Background Perineal defects are commonly encountered during the treatment of conditions such as malignancy, infectious disease, and trauma. Covering large defects in the perineal area is challenging due to its complicated anatomy and the need for functional preservation. Methods Fourteen patients who underwent reconstructive surgery with multiple perforator flaps for defects >$100cm^2$ in the perineal area were included in this retrospective cohort study. Characteristics of the perforator flap operation and postoperative outcomes were reviewed. Results Reconstruction was performed using 2 perforator flaps for 13 patients and 3 perforator flaps for 1 patient. Internal pudendal artery perforator flaps were mainly used for covering the defects. The average defect size was $176.3{\pm}61.8cm^2$ and the average size of each flap was $95.7{\pm}31.9cm^2$. Six patients had minor complications, such as wound dehiscence and partial necrosis of the flap margin, which were corrected with simple revision procedures. Conclusions Multiple perforator flaps can be used to achieve successful reconstructions of large perineal defects that are difficult to reconstruct with other coverage methods.

• 소음진동
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• 제8권3호
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• pp.450-456
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• 1998

A rotordynamic analysis is performed with a centrifuge rotor-bearing system for the raing speed of 100,000 rpm. The system is composed of a centrifuge rotor(or simply the rotor), flexible shaft, motor rotor and shaft, and two support rolling element bearings of the motor shaft. Design goals are to achieve wide separation margins of critical speeds and favorable unbalance responses of the rotor at the associated critical speeds. The latter requirements are especially important as the system crosses multiple numbers of critical speeds and as the system may not have enough separaton margins around the rating speed. As the system adopts an extra-flexible shaft, it is shown that the rotor has satisfactory small unbalance responses over higher criticals while having an unsatisfactory large one at the first critical. To supress this a bumper ring or guide bearing needs to be installed at a suitable location of the flexible shaft. It is also shown that even with the flexible shaft the dynamics of the motor must be incoporated into the full system model to accurately identify the fourth critical speed, which is close to the rating speed, and higher ones. The analysis is based on the finite element method.

• 대한두개안면성형외과학회지
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• 제19권1호
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• pp.75-78
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• 2018

Depression of facial contour after parotidectomy is still challenging to many of surgeons. A 68-year-old man presented with a 4-month history of a painless swelling in both parotid area. The mass was multiple and fixed at the parotid region. We conducted a parotid duct preserving bilateral superficial parotidectomy by one-stage operation to remove the multiple tumors. A lazy S incision was made in both preauricular area and the peripheral branches of the facial nerve were identified using surgical landmark. After dissecting the branches of the facial nerve and parotid duct, main parotid duct was preserved but only small fine ductules from the superficial lobe were ligated. Parotid gland was excised from its anterior aspect with about 1 cm of normal parotid tissue margin. The patient was followed up for 6 years to evaluate postoperative parotid gland function and the computed tomography (CT) was taken. Patient was satisfied with no significant complication such as sunken changes in facial contour, facial nerve function. As far as we know, it is the first study to compare long-term soft tissue contours of soft tissue of duct preserving superficial parotidectomy with duct sacrificing superficial parotidectomy by means of CT findings.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.478-489
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• 2013

The controllability and stability of power systems can be increased by Flexible AC Transmission Devices (FACTs). One of the FACTs devices is Interline Power-Flow Controller (IPFC) by which the voltage stability, dynamic stability and transient stability of power systems can be improved. In the present paper, the convenient operation and control of IPFC for transient stability improvement are considered. Considering that the system's Lyapunov energy function is a relevant tool to study the stability affair. IPFC energy function optimization has been used in order to access the maximum of transient stability margin. In order to control IPFC, a Brain Emotional Learning Based Intelligent Controller (BELBIC) and PI controller have been used. The utilization of the new controller is based on the emotion-processing mechanism in the brain and is essentially an action selection, which is based on sensory inputs and emotional cues. This intelligent control is based on the limbic system of the mammalian brain. Simulation confirms the ability of BELBIC controller compared with conventional PI controller. The designing results have been studied by the simulation of a single-machine system with infinite bus (SMIB) and another standard 9-buses system (Anderson and Fouad, 1977).

• Journal of Power Electronics
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• 제9권2호
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• pp.164-172
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• 2009

Recently, 2-dimensional flat light sources have been attracting much attention for its use in LCD backlight applications because of its high luminous efficiency and uniformity. A long-gap discharge, mercury-tree flat fluorescent lamp has been developed, which shows a high brightness ($>5000\;cd/m^2$) and high luminous efficacy (60 lm/W). Additionally, it has a wide operating margin and stable driving condition with the aid of an auxiliary electrode. For driving the lamp, a narrow pulse power to maintain the glow discharge state is required. Since there has been no research for this kind of lamp driving, this paper proposes a newly developed short-pulse, high-voltage lamp-driving scheme. The proposed lamp system uses a ballast with a coupled-inductor in order to raise the short pulse voltage up to the lamp ignition level and to obtain energy-recovery action during the glow discharge mode. The operation principles are presented and also the system performances such as the lighting efficiency, spatial and angular uniformities are evaluated by hardware experiments. The results show that the proposed lighting system is a good candidate for the next-generation of LCD backlight systems.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권11호
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• pp.643-649
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• 2005

A heart diagnosis system adopts Superconducting Quantum Interface Device(SQUD) sensors for precise MCG(MagnetoCardioGram) signal acquisitions. Such system needs to deal with hundreds of sensors, requiring fast signal sampling md precise analog-to-digital conversions(ADC). Our development of hardware board, processing 64-channel 12-bit in 1 ks/s speed, is built by using 8-channel ADC chips, 8-bit microprocessors, SPI interfaces, and specially designed parallel data transfers between microprocessors to meet the 1ks/s, i.e. 1 mili-second sampling interval. We extend the design into 256-channel hardware and analyze the speed .using the measured data from the 64-channel hardware. Since our design exploits full parallel processing, Assembly level coding, and NOP(No Operation) instruction for timing control, the design provides expandability and lowest system timing margin. Our result concludes that the data collection with 256-channel analog input signals can be done in 201.5us time-interval which is much shorter than the required 1 mili-second period.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.596-600
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• 2003

원자력발전소에서 발생하는 사용후핵연료의 효율적인 관리를 위하여 원자력연구소에서는 사용후 핵연료인 이산화우라늄을 금속우라늄으로 전환시키는 차세대관리 종합공정(ACP)을 개발하고 있으며 공정의 기초가 되는 핫셀을 설계 중에 있다. 핫셀의 설계에 앞서 사용후핵연료를 취급하게 되는 과정에서 발생하는 방사성물질들에 대한 환경영향평가를 수행하여 시설 운영에 대한 안전성을 평가하였다. 각 핵종별 발생량과 방출량을 계산하고 정상운전시와 사고시의 피폭선량을 평가하여 원자력법관련 규제기준과 핫셀이 위치하게되는 IMEF 건물의 안전성분석 기준보다 매우 안전한 결과를 얻음으로써 시설 운영에 대한 안전성을 확보하였다.

• 한국항공운항학회지
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• 제22권3호
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• pp.15-23
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• 2014

There have been CFIT(Controlled Flight Into Terrain) accidents that can be prevented if the crew executed go-around. This study is to analyse the common factors of three typical CFIT accidents of Korea in TEM(threat and error management) frame, and the examples of go-around gate and the countermeasures of eight airlines through the survey facilitating go-around to prevent CFIT. The common factors found in three typical CFIT accidents occurred in Korea or by Korean carriers turned out to be in mountainous terrain, in bad weather while in non-precision approach or circling approach by captain as PF(Pilot Flying) when crew make monitoring errors and communication errors. It also turned out that the crew in all three typical tragic CFIT accidents did not execute go-around in unstabilized approaches. The captains did not respond immediately when first officers advised them to go-around until it is too late. Seven out of eight Airlines answered that they use stabilized approach height as 1,000 feet to be stabilized earlier to have more safety margin by enhancing go-around gate regardless of the weather to prevent CFIT in the survey.