• 태양에너지
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• 제19권1호
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• pp.47-57
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• 1999

A building and the solar are related to the privilege of solar benefit. To make step, it is required to build up an object, chase the position of object and the solar, find the shadow occurrence. On the subject of direct illuminance, an intensive emission of irradiation is proposed to directly project to the benefit area. Simultaneously on the indirect illuminance, the integration of a finite element incident to the benefit area can be multiplied by the hemisphere luminance. A caution should be paid to eliminate the occupation area of the object around on the hemispherical sky, which can help run more accurate prediction.

• Journal of Korean Neurosurgical Society
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• 제49권1호
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• pp.75-78
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• 2011

We report a case of pedicle screw loosening treated by modified transpedicular screw augmentation technique using polymethylmethacrylate(PMMA), which used the anchoring effect of hardened PMMA. A 56-year-old man who had an L3/4/5 fusion operation 3 years ago complained of continuous low back pain after this operation. The computerized tomography showed a radiolucent halo around the pedicle screw at L5. We augmented the L5 pedicle screw with modified pedicle screw augmentation technique using PMMA and performed an L3/4/5 pedicle screw fixation without hook or operation field extension. This modified technique is a kind of transpedicular stiffness augmentation using PMMA for the dead space around the loosed screw. After filling the dead space with 1-2 cc of PMMA, we inserted a small screw. Once the PMMA hardened, we removed the small screw and inserted a thicker screw along the existing screw threading to improve the pedicle screws' pullout strength. At 10 months' follow-up, x-ray showed strong fusion of L3/4/5. The visual analogue scale (VAS) of his back pain was improved from 9 to 5. This modified transpedicular screw augmentation with PMMA using anchoring effect is a Simple and effective surgical technique for pedicle screw loosening. However, clinical analyses of long-term follow-up and biomechanical studies are needed.

• 대한두개안면성형외과학회지
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• 제9권1호
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• pp.17-22
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• 2008

Purpose: For several decades, open reduction has been a controversial issue in mandibular condyle fracture. The authors have successfully used the open reduction and internal fixation with retromandibular approach and have found it to be satisfactory for mandibular condyle fracture. Methods: A total of 10 patients with mandibular condyle fracture underwent open surgical treatment using retromandibular approach. The incision for the retromandibular approach was carried below the ear lobe and the facial nerve branches were identified. Dissection was continued until the fracture site was exposed and internal fixation was performed with miniplate following intermaxillary fixation. The average period of joint immobilization was 1 weeks and the arch bars were removed in 3 weeks on average. The preoperative and postoperative panoramic view and three-dimensional computed tomography were compared. During the follow up period, we evaluated the presence of malocclusion, chin deviation, trismus, pain, click sound, facial nerve palsy, hypertrophic scar and skin fistula. Results: According to the radiographic findings, the fractured condyle was reducted satisfactorily in all patients without any symptoms of facial palsy. During the follow up period ranged form 6 to 12 months, all clinical symptoms were improved except in one case with chin deviation and malocclusion. Conclusion: Using open reduction and internal fixation of mandibular condyle fracture with retromandibular approach, all results were satisfactory with good functional outcomes and minimal complication. We concluded that the open surgical treatment should be considered as the first choice for mandibular condyle fracture management.

• The Korean Journal of Physiology and Pharmacology
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• 제22권5호
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• pp.555-566
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• 2018

Human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) are used in tissue repair and regeneration; however, the mechanisms involved are not well understood. We investigated the hair growth-promoting effects of hUCB-MSCs treatment to determine whether hUCB-MSCs enhance the promotion of hair growth. Furthermore, we attempted to identify the factors responsible for hair growth. The effects of hUCB-MSCs on hair growth were investigated in vivo, and hUCB-MSCs advanced anagen onset and hair follicle neogeneration. We found that hUCB-MSCs co-culture increased the viability and up-regulated hair induction-related proteins of human dermal papilla cells (hDPCs) in vitro. A growth factor antibody array revealed that secretory factors from hUCB-MSCs are related to hair growth. Insulin-like growth factor binding protein-1 (IGFBP-1) and vascular endothelial growth factor (VEGF) were increased in co-culture medium. Finally, we found that IGFBP-1, through the co-localization of an IGF-1 and IGFBP-1, had positive effects on cell viability; VEGF secretion; expression of alkaline phosphatase (ALP), CD133, and ${\beta}-catenin$; and formation of hDPCs 3D spheroids. Taken together, these data suggest that hUCB-MSCs promote hair growth via a paracrine mechanism.

• 전기학회논문지P
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• 제57권4호
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• pp.451-456
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• 2008

In this paper. we experimented and analyzed about evaporation and breaking process of filament by external flames and adsorption pattern in lamp bulb of evaporated filament particle according to the set-up directions of incandescent lamps. In the results of experiments, we could know that filament evaporation behavior of incandescent lamp that is established by down direction happened most vigorously and is difference in adsorption pattern of filament particle that is vaporized according to set-up directions. Also, glass bulbs were melted and filaments were evaporated by external flames, and finally molten marks were discriminated. We expect that become important data that this study finding reveals burnout cause of incandescent lamp in scene of a fire.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.588-590
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• 1994

This paper describes current controlled PWM technique of IPM synchronous motors for a wide variety of speed control applications. The IPM synchronous motors have a saliency, in which the q-axis inductance is larger than the d-axis inductance. As a consequence, there exists a reluctance torque component Thus when this component is added to the torque component produced by the stator currents and the air-gap flux, IPM motor drives are readily applicable where full torque Is required up to full or base speed. They are however limited in their ability to operate in the power limited regime where the available torque is reduced as the speed is increased above its base value. This paper reviews the operation of the IPMSM drives when they are constrained to be within the permissible envelope of maximum inverter voltage and current to produce the rated power and to provide this with the highest attainable rotor speed. The wide variety of speed control strategy is analyzed and the performance is investigated by the computer simulation using actual parameters of a drive system. Simulation results are given and discussed.

• Archives of Plastic Surgery
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• 제34권2호
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• pp.217-221
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• 2007

Purpose: Reconstruction of the soft tissue defect exposing Achilles tendon is a formidable challenge because of the paucity of soft tissue and relatively poor blood supply. This article describes the reconstruction of soft tissue defect exposing Achilles tendon using gracilis muscle free flap and split-thickness skin graft. Methods: From 2000 to 2005, four patients with soft tissue defect exposing Achilles tendon and infection were operated using gracilis muscle free flap and split-thickness skin graft. The defect size ranged from 3.5 to 5cm wide and 6.5 to 8cm long. The mean postoperative follow-up was twenty months. Results: All the flaps were survived without necrosis and infection. We obtained the satisfactory results with good functional and aesthetical outcomes. All cases showed good results with the characteristics of a relatively thin flap without additional debulking procedure. Conclusion: Gracilis muscle free flap with split thickness skin graft could be a good option for reconstruction of soft tissue defect of posterior ankle, exposing Achilles tendon with minimal morbidity of the donor site.

• Archives of Plastic Surgery
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• 제39권1호
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• pp.31-35
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• 2012

Background : Orbital roof fractures are frequently associated with a high energy impact to the craniofacial region, and displaced orbital roof fractures can cause ophthalmic and neurologic complications and occasionally require open surgical intervention. The purpose of this article was to investigate the clinical features and treatment outcomes of orbital root fractures combined with neurologic injuries after early reconstruction. Methods : Between January 2006 and December 2008, 45 patients with orbital roof fractures were admitted; among them, 37 patients were treated conservatively and 8 patients underwent early surgical intervention for orbital roof fractures. The type of injuries that caused the fractures, patient characteristics, associated fractures, ocular and neurological injuries, patient management, and treatment outcomes were investigated. Results : The patients underwent frontal craniotomy and free bone fragment removal, their orbital roofs were reconstructed with titanium micromesh, and associated fractures were repaired. The mean follow up period was 11 months. There were no postoperative neurologic sequelae. Postoperative computed tomography scans showed anatomically reconstructed orbital roofs. Two of the five patients with traumatic optic neuropathy achieved full visual acuity recovery, one patient showed decreased visual acuity, and the other two patients completely lost their vision due to traumatic optic neuropathy. Preoperative ophthalmic symptoms, such as proptosis, diplopia, upper eyelid ptosis, and enophthalmos were corrected. Conclusions : Early recognition and treatment of orbital roof fractures can reduce intracranial and ocular complications. A coronal flap with frontal craniotomy and orbital roof reconstruction using titanium mesh provides a versatile method and provides good functional and cosmetic results.

• Journal of Chest Surgery
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• 제44권2호
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• pp.142-147
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• 2011

Background: Endovascular aortic aneurysm repair (EVAR) has come into use and been widely extended because of the low complication rate and less-invasiveness. This article aimed to describe our experience in the treatment of abdominal aortic aneurysm with EVAR. Materials and Methods: A retrospective review was conducted for the 22 patients who underwent EVAR in a single hospital December 2001 to June 2009. Results: The mean age of the patients was $68.5{\pm}7.6$ years. There were several risk factors and comorbidities in 20 patients (90.9%). The mean diameter of the aortic aneurysms was $61.2{\pm}12.9$ mm. The mean length, diameter, and angle of the aneurysmal neck were $30.5{\pm}15.5$ mm, $24.0{\pm}4.5$ mm, and $43.9{\pm}16.0^{\circ}$, respectively. The mean follow-up period of the patients was $28.8{\pm}29.5$ months. The 30-day postoperative mortality was none. Seven patients (31.8%) had endoleaks during the hospital stay and three patients (13.6%) had endoleaks during the follow-up period. One patient (4.5%) died due to a ruptured aortic aneurysm. The cumulative patient survival rates were 88.2%, 88.2%, and 70.6% at 1, 3, and 5 years of follow-up, respectively. Conclusion: EVAR is currently a safe, feasible procedure for high risk patients with abdominal aortic aneurysm because of low postoperative complication and mortality if patients are selected properly and followed up carefully.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2714-2716
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• 2000

칼라는 물체의 특성을 나타내는 고유한 성질 중의 하나로 칼라 정보를 이용하면 물체를 추적하는데 많은 도움을 얻을 수 있다. 그러나 동일한 칼라의 물체일지라도 조명의 상태나 물체의 형태 등에 따라 실제 이미지 상에 나타나는 칼라는 조금씩 다른 칼라값을 갖는다. 따라서 칼라를 이용하여 물체를 표현하기 위해서는 이미지 상에 나타나는 이러한 물체의 칼라 분포를 효과적으로 모델링할 수 있는 방법이 필요하다. 또한 한번 모델링된 칼라일지라도 물체가 이동하거나 조명이 변화하게 되면 칼라의 분포가 변화하므로 모델링된 칼라가 이러한 변화에도 적절히 대응할 수 있어야 칼라 정보를 이용하여 물체를 추적할 수 있다. 본 논문에서는 이러한 문제를 해결하기 위하여 물체의 칼라 분포를 look-up table을 이용하여 모델링하고 추적하는 물체의 칼라 정보를 이용하여 모델링된 칼라 분포를 다시 갱신하는 적응형 look-up table 방법을 제시하였다. 적응형 look-up table은 모든 칼라값을 테이블로 표현하므로 어떠한 칼라 분포도 모델링할 수 있으며 연산시 단순 참조 방식으로 처리되기 때문에 빠른 계산이 가능하다. 또한 look-up table은 지속적으로 갱신되므로 조명의 변화나 물체의 이동 등으로 인한 칼라 분포의 변화에도 적절히 대응할 수 있다. 본 논문에서는 칼라 정보를 이용하여 물체를 추적하는데 적응형 look-up table을 이용함으로써 적응형 look-up table의 타당성을 검증하였다.