• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.28-38
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• 2013

During the past decades, the B+-tree has been most widely used as an index file structure for disk-resident databases. For the disk based B+-tree, a node update can be cheaply performed just by modifying its associated disk page in place. However, in case that the B+-tree is stored on flash memory, the traditional algorithms of the B+-tree come to be useless due to the prohibitive cost of in-place updates on flash memory. For this reason, the earlier schemes for flash memory B+-trees usually take an approach that saves B+-tree changes from real-time updates into extra temporary storage. Although that approach can easily prevent frequent in-place updates in the B+-tree, it can suffer from a waste of storage space and prolonged search times. Particularly, it is not allowable to process range searches on the leaf node level. To resolve such problems, we devise a new scheme in which the leaf nodes and their parent node are stored together in a single flash block, called the p-node block.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.25-25
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• 2011

폴리올레핀 섬유인 폴리프로필렌과 초고분자량 폴리에틸렌 섬유는 경량성, 속건성, 보온성, 고강도와 같은 여러 장점에도 불구하고 융점(폴리프로필렌: 약 $160^{\circ}C$, 초고분자량 폴리에틸렌: 약 $150^{\circ}C$)이 다른 섬유에 비해 낮아 내열성이 약하여 제품으로서의 가공공정이나 사용 시에 고온을 피해야 하는 주의를 필요로 하고, 곁가지가 거의 없어 섬유분자의 구조가 매우 조밀하며 탄소와 수소로만 이루어진 분자구조에 의한 극단적인 소수성성질은 현재 상용화되어 있는 염료와 염색방법으로의 후염 염색이 거의 불가능한 것으로 알려져 왔다. 이에 본 연구팀에서는 폴리프로필렌과 초고분자량 폴리에틸렌 섬유에 염색 가능한 청색염료를 합성하였다. 염료의 합성에는 leucoquinizarine과 alkylamine(hexyl, heptyl, octyl)의 1:2mole 반응을 이용하여 안트라퀴노이드 구조의 알킬기가 치환된 소수성 염료를 합성하였다. 합성된 염료를 섬유에 염색해본 결과 폴리프로필렌의 경우 농색의 색상강도를 나타냈으며 초고분자량 폴리에틸렌에서는 중색의 색상 강도를 보이는 것으로 확인되었다. 견뢰도 측면에서는 폴리프로필렌의 경우 세탁, 마찰 및 일광견뢰도에서 모두 4~5등급 우수한 결과를 보였다. 초고분자량 폴리에틸렌의 경우 4~5등급의 세탁, 마찰 견뢰도를 가지는 것으로 나타났고, 일광견뢰도는 3~4등급으로 비교적 낮게 나타났지만 공업적으로 널리 이용되는 분산염료에 의해 염색된 제품의 일광견뢰도와 비슷한 수준임을 알 수 있었다.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.11 no.2
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• pp.59-67
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• 2007

Objectives: Pathogenesis treats cause of disease. Pyungweesan is pathogenic prescription of indigestion. This study researched for developing questionnaire of prescribing pyungweesan. Methods: Korean medical doctor classified the patients into two group, pyungweesan symptom group and non pyungweesan symptom group. After that, each group responsed to the questionnaire. We tested for both the reliability and validity of the questionnaire. For validity test, we compared the sum, average and standard deviation of 20 items of pyungweesan symptom group with those of non-pyungweesan symptom group through independent sample t-test, For reliability test, we computerized crohnbach's a value of the items. Results: The developed questionnaire showed remarkable reliability. (Cronbach's ${\alpha}$ =0.854) There were a significant differences on the sum of the 20 items and each 19 item's average and standard deviation, except 1 item; Do you have an irregular discharge from the womb? Conclusions: Based on the results of the above analysis, the korean medical doctor will make an effort to apply the pyungweesan questionnaire clinically. In the future, the additional research is needed.

• Journal of the Korean Vacuum Society
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• v.20 no.3
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• pp.165-175
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• 2011

This paper introduces statistical features observed from measured batch data from the multiple operation state variables of dry vacuum pumps running in the semiconductor processes. The amplitude distribution characteristics of such state variables as inlet pressures, supply currents of the booster and dry pumps, and exhaust pressures are shown to be divided into two or three distinctive regions. This observation gives an idea of using an adaptive parametric model (APM) chosen to describe their statistical features. This modelling, in comparison to the traditional dynamic time wrapping algorithm, is shown to provide superior performance in computation time and memory resources required in the preprocessing stage of sampled batch data for the diagnosis of running dry vacuum pumps. APM model-based batch data are demonstrated to be very appropriate for monitoring and diagnosing the running conditions of dry vacuum pumps.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.106.1-106.1
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• 2013

When strong static magnetic field is applied to the TMP, it is expected that the presence of the magnetic field might retard the velocity of the blades which results in the change of the pumping speed of the TMP. However, such effect of the magnetic field on the TMP has not been well characterized. Thus, under the strong magnetic field, monitoring pumping speed as well as generated heat, pressure, and vibration of the TMP may be an important issue to understand the magnetic field tolerance of the TMP and the development of magnetic shielding technique for the key components of the pump. For this purpose, magnetic field generation system to the vertical direction by a circular current source was firstly designed and suggested [K. Baik et al., 44th Annual Conf. KVS, 22(1), 153, (2012)]. In the current study, another magnetic field generation systems are presented to apply the magnetic field to the horizontal and radial directions by the rectangular current sources and the permanent magnets respectively. Such systems were made to generate at least 50 Gauss of magnetic field along the vertical direction and at least 25 Gauss of magnetic field along the horizontal or radial direction. Current study introduces the evaluation system of the magnetic field along the vertical, horizontal, and radial directions and presents the measured experimental results of the magnetic field when such systems are combined with the equipment where TMP will be installed.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.187-193
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• 2005

The photocatalyst $TiO_2$ thin film was made from titanium (IV) isopropoxide, ethanol, and HCl by sol-gel method. The surface observation by SEM showed the sample that was coated 5 times at $500^{\circ}C$ had good properties. The component ratio, in atom% of O : Ti by EDX analysis, of 61 : 39 by spin coating was superior than dip coating. It was found that crystal structure changed from anatase phase to rutile phase as a function of the temperature of thin film fabrication, and this was measured by XRD. The photolysis efficiency of total organic compounds (TOC) by lighting UV beam on $TiO_2$ thin film showed 20%~65% within 1 h, and decreased slowly thereafter.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.273-280
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• 2001

Objectives : The purpose of this study is to assess the long-term outcome and delayed complications of Gamma Knife radiosurgery for low grade glioma(LGG). Methods : Among 31 patients of LGG who had been treated by using Leksell Gamma Knife between March 1992 and December 1996, we could follow up more than 5 years(range 5-9 years) in 17 patients and evaluated their clinical feature, changes of tumor volume and post-radiosurgical complications. Results : During the mean follow-up period of 7.6 years, the tumor was decreased in 5 patients(29.4%), unchanged in 4(23.5%), increased in 4(23.5%) and recurred in 4(23.5%). The tumor control rate was 52.9%(9/17). We have experienced eighteen postradiosurgical complications in 10 patients(58.8%). Early complication was none and delayed complications included radiation necrosis with cyst in ten cases, bleeding in five, radiation-induced edema in one and malignant transformation in one. Two patients ultimately died as a result of tumor progression during the follow-up period. The mortality rate was 11.7%. Conclusion : Gamma Knife radiosurgery may be useful as an adjunctive therapy for small volume, deep-seated LGG. Although radiosurgery can effectively prevent growth of solid tumor, several delayed complications such as radiation necrosis, cyst formation, bleeding or malignant transformation can develop during the long-term followup period. Because of the possible slow growth rate of LGG and development of the delayed complications, the long-term efficacy of radiosurgery requires further analysis.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.364-367
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• 2001

A 4-month-old female patient admitted because of hydrocephalus. She was premature infant with germinal matrix hemorrhage at gestational period 27 wks. A ventriculoperitoneal shunt with a low-pressure type valve was placed. Follow-up CT scan obtained 3 months after VP shunt placement, revealed a new Lt. middle cranial fossa cyst. The girl was readmitted to hospital at 7 months after VP shunt placement, complaining of lethargy and vomiting. A CT scan was demonstrated a increase in size of a cyst, She subsequently underwent a left-sided pterional craniotomy with partial excision of membrane and cyst fenestration into the basal cisterns. Follow-up CT scan after 18 months revealed reaccumulation of cyst, the girl was reoperated on. After 2 months, the size of cyst was not decreased. Finally, She underwent a cystoperitoneal shunt. Follow-up CT scan after 5 months was demonstrated disappeared cyst and reexpansion of brain parenchyma. We report the development of a symptomatic sylvian fissure arachnoid cyst developed after ventriculoperitoneal shunt.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.352-355
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• 2001

The authors report two cases of familial hemifacial spasm according to the clinical and three dimensional shortrange magnetic resonance angiography(3D-SRMRA) findings. In the family of the first case, there were five patient's with acquired hemifacial spasm in successive generations. Three male and two female patients in successive generations of the same family developed acquired hemifacial spasm. Four patients were on the left side and one was on the right side. In the family of the second case, there were three patient's with acquired hemifacial spasm in successive generations. Two brothers developed left-sided hemifacial spasm. 3D-SRMRA finding of the probands demonstrated that both anterior inferior cerebellar artery in first case and anterior inferior cerebellar artery & vertebral artery in second case offend the 7th cranial nerve respectively. The presence of familial clustering of these rare disorders suggest an underlying genetic predisposition. All family pedigrees suggest that a pattern of autosomal-dominant inheritance with partial penetrance.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.235-241
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• 2001

Objective : Controversy exists which surgical treatment better in lumbar grade I spondylolisthesis, decompressive laminectomy with or without lumbar instrumentation. Methods : Out of Sixty-four patients with lumbar spondylolisthesis underwent surgery, 18 patients operated with decompressive laminectomy alone and 44 patients with decompession and lumbar instrument, during recent 5-years between January, 1994 and December, 1998. The author studied a long term follow-up in the above two groups to analyzing the overall clinical outcomes in each group and to determining the incidence of pos-toperative radiologic instability. Results : 1) Overall postoperative symptoms improvement were not so different in both groups. 2) Postoperative progressive subluxation is more common after decompressive laminectomy without instrumentation than with instrumentation group. 3) Overall clinical outcomes were slightly better in decompressive laminectomy without instrumentation than with instrumentation group but there was no significant difference. 4) Postoperative radiologic changes did not seem to influence the patient-reported clinical outcomes. 5) Postoperative complications is more common in decompressive laminectomy with instrumentation group than without instrumentation group. Conclusion : In the surgical management of grade I spondylolisthesis, the efficiency and superiority of surgical treatments requires the cost effectiveness and risk/benefit analysis of decompressive laminectomy with or without instrumentation. Therefore, Further detailed studies of long term follow up in a large number of patients in each group are needed for choice of best treatment.