• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.352-354
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• 2011

The performance of multihop cognitive radio networks (CRN) can be improved significantly by using multiple channels in spectrum underlay fashion. However, interference due to the sharing of common radio channel and congestion due to the contention among those flows that share the same links become an obstacle to meet this challenge. How to control efficiently congestion and allocate power optimally to obtain a high end-to-end throughput is a key objective in this work. We reexamined the Network Utility Maximum (NUM) problem with a new primary outage constraint and proposed a novel resource allocation strategy to solve it effectively and efficiently.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1279-1300
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• 2017

In the interweave cognitive networks, the interference from the primary user degrades the performance of the cognitive user transmissions. In this paper, we propose an adaptive cooperation scheme in the interweave cognitive networks to improve the performance of the cognitive user transmissions. In the proposed scheme for the bidirectional communication of two end-source cognitive users, the bidirectional communication is completed through the non-relay direct transmission, the one-way relaying cooperation transmission, and the two-way relaying cooperation transmission depending on the limited feedback from the end-sources. For the performance analysis of the proposed scheme, we derive the outage probability and the finite-SNR diversity multiplexing tradeoff (f-DMT) in a closed form, considering the imperfect spectrum sensing, the interference from the primary user, and the power allocation between the relay and the end-sources. The results show that compared with the direct transmissions (DT), the pure one-way relaying transmissions (POWRT), and the pure two-way relaying transmissions (PTWRT), the proposed scheme has better outage performance. In terms of the f-DMT, the proposed scheme outperforms the full cooperation transmissions of the POWRT and PTWRT.

• 복식
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• 제56권7호
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• pp.142-151
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• 2006

Bikini, a brief two-piece bathing suit revealing the wearer's navel, was first introduced in Paris, in 1946. However, it was not until the late 1950s that Americans were ready to adopt bikinis. Therefore, I focused on the following research questions to understand the popularization process of bikinis in the United States, from 1946 to the 1960s: 1. Why were Americans initially hesitant to adopt the bikini? 2. What were the factors that influenced the popularization of the bikini among Americans in the late 1950s? Primary sources including Bazaar. Madmoiselle, Vogue, The New York Times, and Life were reviewed. I referred to secondary sources on the history of fashion and American popular culture to interpret primary sources. According to the primary sources, Americans were hesitant to adopt the bikini, partly due to the excessive demand on the wearer's figure. However, the conservative social atmosphere during Cold War would not accept immorality and obscenity which would threaten America's future. Therefore, the campaigns against the sex industry, which developed prominently after WWII, predominated American society during the 1950s. Under this atmosphere, a small number of pictures and articles on bikinis appeared in the primary sources. Bikinis were only found in advertisements including sun lotions and hair removers. However, American society had to accept the change in sexual mores by the end of the 1930s. Body-revealing fashions including miniskirts, hot pants, and see-through material reflected the change in social convention. By the end of the 1950s, the number of pictures and articles on bikinis also began to increase in the primary sources. More Americans adopted bikinis with the increasing number of private pools and European trips. The vogue of sun-tanning and movies featuring bikinis further contributed to their popularity in the late 1930s and into the 1960s.

• Journal of Korean Neurosurgical Society
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• 제48권4호
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• pp.363-366
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• 2010

Vertebral artery (VA) injury is a rare and serious complication of cervical spine surgery; this is due to difficulty in controlling hemorrhage, which can result in severe hypotension and cardiac arrest, and uncertain neurologic consequences. The authors report an extremely rare case of a 56-year-old woman who underwent direct surgical repair by end-to-end anatomosis of an unanticipated VA injury during C2 pedicle screwing. Postoperatively, the patient showed no neurological deterioration and computed tomography angiography of the VA demonstrated normal blood flow. Although direct occlusion of an injured VA by surgical ligation or endovascular embolization has been used for management of an unanticipated VA injury during surgery, these methods may be associated with significant morbidity and mortality. However, despite its technical demand, microvascular primary repair can restore normal blood flow and minimizes the risk of immediate or delayed ischemic complications. Here we report an iatrogenic VA injury during C2 pedicle screwing, which was successfully treated by end-to-end anastomosis.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제9권4호
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• pp.317-328
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• 2005

The aim of this study is to investigate future teachers' skills that can make problem solving methods concrete for 7-11 year old students. For the students in the concrete operations level, solutions of word problems should also be taught by concreting. But most of teacher candidates can not solve the problems without algebra because they got used to solve the word problems with algebra during their high school and university education. In this study, whether the teacher candidates have the skills of solving the primary school level problems without using algebra or not are being observed. At the end of this observation it is determinated that primary level teacher candidates generally prefer using algebra operations because of their former habits. The results show that in the education of the primary level teacher candidates, there is the need of developing the solving skills using figures and diagrams without algebra rather than algebraic solutions in word problems.

• 사상체질의학회지
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• 제28권4호
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• pp.350-360
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• 2016

Objective The aim of this study was to report significant improvement of primary insomnia in a Soyangin Cold-related diarrhea accompanied by abdominal pain Symptomatic pattern Patient. Methods The patients were diagnosed with Soyangin Cold-related diarrhea accompanied by abdominal pain Symptomatology(身寒腹痛亡陰證) and treated with Hyungbangjihwang-tang(荊防地黃湯). The primary outcome measures for this study were condition of sleep using a questionnaire with Pittsburgh Sleep Quality Index (PSQI) Secondary outcome assessment included change of original symptoms such as patient's digestion, sweating and feces. Result The symptoms of primary insomnia improved by the end of the a treatment period without side effect. original symptoms were also changed. Conclusions This result show Hyungbangjihwang-tang(荊防地黃湯) can be used to treat primary insomnia in a Soyangin Cold related Mangeum Symptomatic Pattern accompanied by abdominal pain Symptomatology(身寒腹痛亡陰證). Meaning and process of primary insomnia are different according to Sasang Constitutions.

• Journal of Plant Biology
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• 제33권1호
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• pp.65-72
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• 1990

An anatomical study was conducted in order to elucidate the development of primary and secondary ray in Robinia pseudoacacia L. The height of primary ray near pith decreases progressively toward periphery, while the width and number per unit area gradually increase, and then the height, width and number remain somewhat constant. Secondary ray originates from the segmentation of fusiform initials or division of the side or end of fusiform initials at the middle of the first growth layer. And after the height and width of secondary ray increases to some extent, it remains constantly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.130-132
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• 1997

In this paper, we propose a new type of tubular linear induction motor(TLIM) with two-dimensional motion. The proposed motor consists of four short primary LIMs arranged on a same circumference and a common secondary. By adopting independently energized ring-windings to the primary, we can expect the reduction of coil-end region and the freedom of alternating current supply. The secondary conductor is capable of producing anyone of rotary, linear, and helical motions by controlling the phase of supply currents in each primary winding. From the 3-D finite element analysis and the experiment, we derive the feeding conditions to increase the subsidiary rotary-force and an optimal arrangement of primary currents to reduce the number of slot.

• Journal of Chest Surgery
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• 제22권5호
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• pp.834-838
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• 1989

Tracheal stenosis is being encountered more frequently as ventilatory support and cuffed tubes are increasingly used for treatment of respiratory failure. We experienced 13 cases of tracheal stenosis treated surgically at department of Thoracic and Cardiovascular Surgery, school of medicine, Kyung Hee university during the 4 years. The causes of tracheal stenosis were prolonged endotracheal intubation 5 cases, tracheostomy 3 cases, tracheal tumor 2 cases, thyroid tumor 1 case and congenital double aortic arch 1 case. The methods used to manage the tracheal stenosis were tracheal resection % end to end anastomosis 8 cases, 2 cases of subglottic stenosis were underwent primary laryngotracheal anastomosis, Lt. aortic arch division 1 case, and stent insertion 2 cases. In two cases, who had 6 cm in length of tracheal stenosis, we were underwent tracheal resection k end to end anastomosis with supralaryngeal release procedure. Postoperative courses were uneventful except one case with tracheal tumor.

• Journal of Chest Surgery
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• 제13권4호
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• pp.496-496
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• 1980

A 37 year old male patient was suffered from severe labored breathing caused by post tracheostomy stenosis, which was localized at the mediastinal trachea [cuffed tracheal stenosis] and ranged 1.5 cm in length and approximately 3 ram. in diameter on tracheogram. After dilation of tracheal stenosis with dilator, endotracheal intubation was tried for induction of anesthesia and control of respiration during operation. A tube was placed just beyond the tracheal stenosis without respiratory difficulty. Under the endotracheal anesthesia, circumferential resection of the mediastinal trachea containing the stenosis, approximately 2 cm in length [4 tracheal rings}, was carried out and primary direct end to end anastomosis was performed with interrupted submucosal sutures [3-0 Dexon] and mobilization of trachea Postoperative tracheostomy was not performed. The patient was completely relieved from dyspnea immediately after operation. Post-operative convalescence was entirely uneventful and at present, about 3 months after operation, he is now conducting a usual life. From the literature and our experience, the etiology and treatment of post-tracheostomy stenosis were discussed.