• Journal of the Korean Institute of Telematics and Electronics B
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• v.28B no.5
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• pp.421-430
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• 1991

This paper investigated the errect of the right-half-plane zero on stability in the buck-boost DC-DC converter which is one type of the switching regulator and the stability region for the variation of the output current is obtained by evaluating the feedback gain. And it is clarified that the damping ratio decreases gradually by increase of the feedback loop gain and the regulation system of the converter becomes unstable, and from the transient response analysis we obtainedthe stability region about this converter. From above result it is known that the stability decreases by the existence of the right-half-plane zero. For the improvement of stability, we carried out one pole compensation in feedback circuit and obtained the avaliable stability region in relation to the gain bandwidth product from the stability and transient response analysis. These results were established experiment.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.117-120
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• 2001

Low back pain has been known as the most frequent musuculoskeletal disorders in modern industrial society and cost by low back pain is increasing mon and more. The asymmetric lifting has been identified as a major risk factor of low back pain. In this study, the muscle activity and muscle exertion level during asymmetric load handling (without trunk flexion) was estimated. The results of normalized MVC measurement were decreased about 16％, 24％, 34％ respectively as the asymmetric angle was $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. From the results of EMG measurement contralateral muscles were more active than ipsilateral muscles. RMSEMG values of right erector spinae muscles were decreased as the work posture went to 90$^{\circ}$ and those of left erector spinae muscles were increased until the asymmetric angle was 40$^{\circ}$ but decreased continually over 40$^{\circ}$. And for seven of subjects, activities of left and right latissimus dorsi muscles were maintained constantly, while for remainer, those were irregular.

• Korean Journal of Logic
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• v.23 no.1
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• pp.1-23
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• 2020

This paper deals with mianorm-based logics with right and left n-potency axioms and their fixpointed involutive extensions. For this, first, right and left n-potent logic systems based on mianorms, their corresponding algebraic structures, and their algebraic completeness results are discussed. Next, completeness with respect to algebras whose lattice reduct is [0, 1], known as standard completeness, is established for these systems via Yang's construction in the style of Jenei-Montagna. Finally, further standard completeness results are introduced for their fixpointed involutive extensions.

• Journal of Korean Library and Information Science Society
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• v.26
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• pp.205-234
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• 1997

Special Libraries are not the organizations established and administered by the Library and Reading Promotion Law, but the ones organized to provide necessary knowledge and information required in the works performed by the staff of organizations. The goal of special libraries is to provide the information and materials required by the parent organizations, preferably, at the right time and in the right form. In accordance with the specialization of social structure, the number of special library has been increasing. Especially, industries need industrial information in their introduction of new management techniques and in the processes of technical development, so special libraries attached to industries have remarkably been increased. Special libraries, along with academic libraries, are the organizations providing necessary materials for the specialists who are producing knowledge of every field in the society. However, apart from academic libraries, the organizations, manpower, works, collections and services of special libraries have not been properly investigated and known. This research has tried to identify if those factors are provided for propose services. The result shows which factors are fulfilled enough or which ones need enforcement.

• Journal of Chest Surgery
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• v.12 no.3
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• pp.233-239
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• 1979

Ventricular septal defect associated with patent ductus arteriosus is well known cardiac anomaly that can be treated successfully by operation. This anomaly is found at low frequency. Seven cases of the combined malformation were operated on during the period from 1959 to 1978 in the Department of Thoracic Surgery, Seoul National University Hospital. Right heart catheterization and retrograde aortogram can diagnose the disease correctly. Staged operation in one case and one-stage operation in 5 patients were done. In all cases of the open heart surgery the closure of the ductus was done by transpulmonary suture of the PDA opening. Among 6 patients of the open heart surgery 2 operative death [33.3%] and one late death [total 50%] were noted. Four type II and one type I and one Type IV VSDs were found. In one case the anomaly was accompanied with aortic insufficiency by herniation of the right coronary cusp through Type I VSD.

• The Journal of the Korean dental association
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• v.18 no.2 s.131
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• pp.103-108
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• 1980

The occurrence of odontogenic epithelium in the well of a dentigerous cyst is a well known entity. This epithelium usually remains inactive and does not have clinical significance. However, these small inactive islands of epithelium may be stimulated, resulting in an ameloblastoma. Therefore correct diagnosis and proper treatment are very important. A 15 year-old boy came to the outpatient clinic on August 13, 1979. The Chief complaint was pain, difficulty in mouth opening and swelling of the right mandible of 1 month's durations. With the X-ray filming, it was revealed that dentigerous cyst had been originated from the third molar, occurred in posterior region of the right mandible involving the 1st and the and molar and the portion just beneath the sigmoid notch area. Pus discharged from the gingival sulcus distal to the 2nd molar and it was sure that the cyst had been infected. Enucleation performed with careful excision of all cyst wall was successfully carried out, and recovery and heading were rapid and uncomplicated.

• Journal of Chest Surgery
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• v.24 no.10
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• pp.1024-1027
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• 1991

We experienced a case of giant cell tumor arising from the right 2nd rib in the diagnostic and therapeutic thoracotomy at our department of Thoracic and Cardiovascular Surgery, Chungnam Univ. Hospital in May 3rd, 1991. The reports of this tumor are very rare and are known to have the incidence of 1 percent or less of all giant cell bone tumor. The tumor of the right 2nd rib, infant head-sized, covered with parietal pleura was invaded into the vertebra on operation finding. The tumor was resected partially[three fourths] and revealed to be the giant cell tumor on pathologic finding. At now, the patient is taking the radiotherapy to achieve the therapeutic goal to the remnant tumor.

• Korean Journal of Bronchoesophagology
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• v.5 no.1
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• pp.68-72
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• 1999

Odontogenic keratocyst is a central destructive lesion of the jaws characterized by a thin, fragile layer of orthokeratinizing or parakeratinizing stratified squamous epithelium. Correlation between the histologic type and the recurrence ratio remains a subject of controversy, and multiple cysts are known to be associated with the nevoid basal cell syndrome. We experienced a case of multiple odontogenic keratocyst in a 25 year-old male patient involving bilateral mandible and maxilla. The cystic mass of the right maxilla was removed by Caldwell-Luc's approach and the right mandibular mass was removed by intraoral approach but the teeth that were impacted in the mandibular bone were remained in order to prevent an iatrogenic fracture.

• The Korean Journal of Pain
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• v.26 no.2
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• pp.191-194
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• 2013

Pseudoaneurysm of the abdominal wall is a possible but very rare clinical entity. It is a known complication of surgery, trauma, or arterial puncture, but it is rarely spontaneous. Even though it can usually present with a wide range of local symptoms, it can cause referred pain via spinal cord, which is cross-excited with afferent sympathetic nervous system. We report a case of right arm pain which was referred from a small abdominal pseudoaneurysm like a referred pain from gall bladder. This rare entity should be considered in the differential for pain management in case that the pain does not resolve with medication or interventional pain management.

• Bulletin of the Korean Mathematical Society
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• v.32 no.1
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• pp.85-91
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• 1995

For a locally compact Hausdorff space, we denote by $C_0(X)$ the Banach space of all continuous complex valued functions defined on X which vanish at infinity, equipped with the usual sup norm. In case X is compact, we write C(X) instead of $C_0(X)$. A well-known Banach-Stone theorem states that the existence of an isometry between the function spaces $C_0(X)$ and $C_0(Y)$ implies X and Y are homemorphic. D. Amir [1] and M. Cambern [2] independently generalized this theorem by proving that if $C_0(X)$ and $C_0(Y)$ are isomorphic under an isomorphism T satisfying $\left\$\mid$ T \right\$\mid$ \left\$\mid$ T^1 \right\$\mid$ < 2$, then X and Y must also be homeomorphic.