• Journal of Power Electronics
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• 제12권4호
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• pp.677-688
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• 2012

The vibratory conveyors with electromagnetic drive are used for performing gravimetric flow of granular materials in processing industry. By realizing free vibrations of variable intensity and frequency over a wide range through application of the electromagnetic actuator, suitable power converter, and the corresponding controller, continuous conveyance of granular materials have been provided for various operating conditions. Standard power output stages intended for control of vibratory conveyance using thyristors and triacs. Phase angle control can only accomplish tuning of amplitude oscillations, but oscillation frequency cannot be adjusted by these converters. Application of current controlled transistor converters enables accomplishing the amplitude and/or frequency control. Their use implies the excitation of a vibratory conveyor independent of the supply network frequency. In addition, the frequency control ensures operation in the region of mechanical resonance. Operation in this region is favourable from the energy point of view, since it requires minimal energy consumption. The paper presents a possible solution and advantages of the amplitude-frequency control of vibratory conveyors by means of a current controlled power converter.

• Archives of Reconstructive Microsurgery
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• 제13권2호
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• pp.117-122
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• 2004

Purpose : The aim of this study was to evaluate the efficacy of arterialized venous flap in finger flexion contracture correction. Materials and methods : From 2002 to 2004, we have performed 10 arteriaized venous flap for treatment of severe flexion contracture in digit. The duration of flexion contracture was from 1 year to 50 years. The cause of contracture were bum scar(7 cases), postoperative contracture(2 cases) and other(l case). We evaluated the survival of flap, flap size, recovery of flexion contracture and subjective satisfaction. Results : All arterialized venous flap survived. The marginal minimal skin necrosis developed in 2 cases. The flap size was average $5.2{\times}3.5cm$. The recovery of flexion contracture was 87% compared with non affected side. 9 patients(90%) satisfied the results of operation. Conclusion : Arterialized venous flap is one of the useful procedure in treatment of finger flexion contracture because it has many advantages such as thin and good quality, variable length of pedicle, preservation of major vascular pedicle, less operation time and in addition possibility of various modifications.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.723-726
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• 2005

Osmidrosis axillae is a distressing problem characterized by foul odor at the axillae due to excessive apocrine sweat gland secretion. We introduce a new non-surgical method using a specially insulated needle and high frequency electrocoagulator. From September 2001 to January 2005, 52 patients were treated with this procedure for osmidrosis axillae. In authors' procedure, insulated needle which was designed to protect skin and dermal layer was inserted into the deep dermis of axilla area and apocrine sweat glands were removed by electrocoagulation. Fifty two patients were evaluated more than 6 months after surgery. Among these patients, 48 patients received secondary coagulation procedure. After second operation, all patients were satisfied with postoperation results. We conclude that our method has several advantages such as 1) short operation time, 2) no necessity of postoperative immobilization of shoulder joints, 3) no need of hospitalization, 4) minimal scarring and no bleeding, 5) prevention of skin necrosis, 6) a safer operative method for recurred cases as a secondary method.

• Clinics in Shoulder and Elbow
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• 제3권1호
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• pp.54-60
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• 2000

As a surgical treatment of ulnar nerve entrapment syndrome includes simple decompression, medial epicondylectomy, and anterior transposition of the ulnar nerve into a subcutaneous or submuscular bed have been widely used. Despite many reports of these surgical procedure, there is little to guide the choice of one surgical technique. The purpose of our study is to analyse clinical and electrodiagnostic result after minimal invasive decompression by decompression and medial epicondyloplasty(deepening of ulnar groove). We have experienced 9 cases of ulnar nerve entrapment syndrome who were treated with decompression and medial epicondyloplasty. Male were five and female were four. The mean age at operation was 36 years ranging from 23 to 47 years. Operative procedure was to incise the medial intermuscular septum and aponeurotic arch of flexor carpiulnaris and to deepen the ulnar groove. Patients are allowed to do range of motion(ROM) exercise on the average 5days. All patient were relieved pain and improved motor and sensory function, and this procedure allows early ROM exercise after operation because the muscle have not been detached.

• 상하수도학회지
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• 제30권5호
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• pp.491-500
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• 2016

Pressure monitoring is expected to be expanded in a water distribution system according to accelerated development of smart water network management technologies caused by appearances of affordable digital infrastructures like computing, storage and bandwidth. However, the placement of pressure sensors has been determined by engineer's technical decisions since there is no well-defined criteria for deciding a suitable location of pressure sensor. This study presents a placement method of pressure sensors based on the consideration of allowable error in calibrating water network analysis modeling. The proposed method is to find a minimum set of pressure sensors for achieving a reliable management of water transmissions main and increasing the efficiency of their real-time operation. In the case study in Y area's transmission main, the proposed method shows equally distributed pressure sensors in terms of hydraulics. It is expected that the proposed method can be used to manage transmission mains stably and construct a robust real-time network analysis system as a minimal criteria.

• Food Science and Biotechnology
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• 제14권3호
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• pp.380-386
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• 2005

Optimal conditions of ultrafiltration (UF) and nanofiltration (NF) were investigated for separation and concentration of isoflavones and oligosaccharides from Sunmul. Levels of COD, BOD, and suspended solids (SS) in UF and NF permeates were also determined to evaluate effectiveness of these processes for reducing water pollution. Optimal UF operation conditions to achieve minimal fouling and maximal flux were $33-34^{\circ}C$ operating temperature and 2.3-2.4 bar trans-membrane pressure. Recovery yields of isoflavones and oligosaccharides in UF retentate were 11.49-28.16% and 12.77-27.57%, respectively. Increase in volumetric concentration factor (VCF) resulted in more functional compounds of isoflavones and oligosaccharides passing through UF membrane. Total isoflavone and oligosaccharide yields decreased by 3% as VCF increased from 6.0 to 8.0 and from 8.0 to 10.0, while decreased significantly by 10% as VCF decreased from 4.0 to 6.0. Optimal NF operating conditions were 192-195 psig operating pressure at $30-33^{\circ}C$. Total yields of isoflavones and oligosaccharides significantly decreased at VCF 8.0, whereas did not decrease up to VCF 6.0 during NF operation. Therefore, VCF 6.0 was recommended for economical process. COD and BOD decreased by more than 98% after NF process, and SS were not detected after UF process. These results indicated sequential filtration process was useful for separation of isoflavones and oligosaccharides from Sunmul and for reducing water contaminants.

• 한국IT서비스학회지
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• 제14권4호
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• pp.15-30
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• 2015

SMBA (Small and Medium Business Administration) and TIPA (Korea Technology and Information Promotion Agency for SMEs) have operated the Business Innovation Platform for SME Informatization based on cloud computing technology with the cooperation of seven industry cooperatives since 2013. This project will evolve into the open market platform where service providers and users voluntarily participate and transact. This research conducts the literature review about the concept of open market and the empirical analysis through survey for the software providers and the future users regarding the future operation methods. The policy about how the open market strategy for the business innovation platform needs to be designed and implemented are organized as the three differentiated government support strategies. The first is to provide free IT services including specialized core operation support S/W which is developed only for the small or home office group of firms which lack minimal informatization capability and budget. The second is to augment IT platform service through incorporating ERP supplier initiated commercial S/W sales window for those firms having medium level informatization capability. This includes to provide IT support for customization and system integration with existing government subsidized S/W. The third is to provide upgrading services of existing S/W functions to facilitate better system utilization. The results provide useful insight for government role to enhance SME competitiveness using IT.

• 대한두개안면성형외과학회지
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• 제14권1호
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• pp.46-49
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• 2013

Facial deformity after nerve injury changes ones' social life. We experienced a few patients with healthy early recovery of muscle contraction after the operation with soft tissue wraparound splint. Under general anesthesia, exploration to find as many injured nerve stumps with ${\times}2.5$ loopes was undertaken at first. Interfascicular repair was done with minimal tension by 10-0 nylon under a microscope, and the suture site was sealed by approximating the surrounding fat flaps. This conjoined adipose tissue flap was a splint as a wraparound environment to reduce the tension in the coaptation site, and to increase the relative concentration of releasing neurotrophic factors by surrounding it. A 45-year-old man fell down in a drunken state and had deep laceration by broken flowerpot fragments with facial muscle weakness on the right cheek. His injured mandibular branches of the facial nerve were found. A 31-year-old female suffered from motionlessnesss of frontalis muscle after a traffic accident. She had four frontal branches injured. The man had his cheek with motion after seven days, and the woman two months after the operation. The nerve conduction test of the woman showed normalized values. Facial nerve repair surrounded by adipose tissue wraparound splint can make the recovery time relatively short.

• 한국산업보건학회지
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• 제29권3호
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• pp.278-288
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• 2019

Objectives: The objectives of this study are to summary controversy over health risks among semiconductor workers, to review major cancer risk results conducted in semiconductor operation and to evaluate occupational health activities in Korea for controlling hazardous agents generated in semiconductor operations Methods: Major occupational health issues that has been social controversies among semiconductor workers since 2007 were reviewed through an extensive literature, report and article review. Results: Since a female semiconductor worker aged 22 died from leukemia in 2007, job-association of a number of former semiconductor workers with various types of cancer and rare diseases have been denied by the Korea Workers' Compensation and Welfare Service (KWCWS), but some of them were later awarded compensation as an occupational disease by the administrative court. Two epidemiologic cancer risk studies conducted in Korea found increased risks in leukemia and non-Hodgkin's lymphoma among semiconductor workers. Various legal occupational health activities taken in semiconductor industry were found to fail to assess a complex characteristics of semiconductor operations, such as drastic changes in chemical use, processes, and technology, multiple exposure. National compensation regulation also showed the limitation to evaluate job-association of semiconductor workers who had worked in semiconductor operation. Conclusions: National legal measures should be taken to improve several occupational health activities and duties for protecting workers. In addition, the KWCWS program should be revised so that all workers who meet minimal job or environment associations can be compensated.

• 안보군사학연구
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• 통권1호
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• pp.345-360
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• 2003

To build an information oriented armed forces, the Korean military telecommunication networks adopt TCP/IP standard communication infrastructures based on ATM packet switched networks. Utilizing this network infrastructure, the Korean armed forces also applies to the areas of battleship management for efficient operation command controls and resource management for efficient resource allocations. In this military communication networks, it is essential to determine the least cost network topology under equal performance and reliability constraints. Basically, this type of communication network design problem is known in the literature as an NP Hard problem. As the number of network node increases, it is very hard to obtain an optimal solution in polynomial time. Therefore, it is reasonable to use a heuristic algorithm which provides a good solution with minimal computational efforts. In this study, we developed a simulated annealing based heuristic algorithm which can be utilized for the design of military communication networks. The developed algorithm provides a good packet switched network topology which satisfies a given set of performance and reliability constraints with reasonable computation times.