• Journal of Korean Neurosurgical Society
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• 제52권3호
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• pp.234-239
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• 2012

Objective : Chronic subdural hematoma (CSDH) is a typical disease that is encountered frequently in neurosurgical practice. The medications which could cause coagulopathies were known as one of the risk factors of CSDH, such as anticoagulants (ACs) and antiplatelet agents (APs). Recently, the number of patients who are treated with ACs/APs is increasing, especially in the elderly population. With widespread use of these drugs, there is a need to study the changes in risk factors of CSDH patients. Methods : We retrospectively reviewed 290 CSDH patients who underwent surgery at our institute between 1996 and 2010. We classified them into three groups according to the time of presentation (Group A : the remote period group, 1996-2000, Group B : the past period group, 2001-2005, and Group C : the recent period group, 2006-2010). Also, we performed the comparative analysis of independent risk factors between three groups. Results : Among the 290 patients, Group A included 71 patients (24.5%), Group B included 98 patients (33.8%) and Group C included 121 patients (41.7%). Three patients (4.2%) in Group A had a history of receiving ACs/APs, 8 patients (8.2%) in Group B, and 19 patients (15.7%) in Group C. Other factors such as head trauma, alcoholism, epilepsy, previous neurosurgery and underlying disease having bleeding tendency were also evaluated. In ACs/APs related cause of CSDH in Group C, significantly less proportion of the patients are associated with trauma or alcohol compared to the non-medication group. Conclusion : In this study, the authors concluded that ACs/APs have more importance as a risk factor of CSDH in the recent period compared to the past. Therefore, doctors should prescribe these medications carefully balancing the potential risk and benefit.

• 한국항해학회지
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• 제16권2호
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• pp.53-78
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• 1992

GMDSS-the Global Maritime Distress and Safety system which is utilizing the new technologies such as satellite communication system, DSC and NBCP-is effectuated not only by the amendment of SOLAS but also by the conference of RR and IMO's MSC, and will be the major factor of the variation of the demand and supply of Radio Operators. To cope with the GMDSS voluntarily, regulations relating to the radio installation, the posting of Radio Operators, the bounds of duty, etc. must be established and the demand and supply of Radio Operators which take charge of the system must be accomplished pertinently. In this study, the authors suggested some practical schemes to improve the effect of policy as follow. 1. The Ministry of Communication must supervise strictly the arrangement of Radio Operators, especially relating tot he legally qualified complement of Radio Station, and must review the official certification system to upgrade the quality of Radio Operators. 2. The Ministry of Communication must take overall charge of the qualitifications and technical standards of Radio Operators, the extent of their engagement, etc. which are provided by International Regulations. 3. Relating Administrations must cooperate with Shipping Companies in onboard-training to foster and ensure the manpower of Radio Operators. 4. Institutional devices to drive the resolute investment in education and training for mariners, especially for the ship's officers, must be prepared. 5. The Communication Administration and the Korea Maritime and Port Adminstration(KMPA) must cooperate mutually in the balance of the demand and supply of Radio Operators and use make their best to realize more harmonious policies on the demand and supply of manpower.

• 한국항해학회지
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• 제18권1호
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• pp.39-61
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• 1994

GMDSS(the Global Maritime Distress and Safety System), which is utilizing recently developed systems such as satellite communications and positioning system, digital communication system, computer and microelectronics technology, etc., has been adopted by International Maritime Orgnization(IMO) and coordina-ted with such organization as the International Telecommunication Union(ITU), World Meteorological Organizatoion(WMO), etc. This system took effect partly on February 1st 1992 according to the 1988 SOLAS Amemdments and, after some more complementary measures, will be fully operational by February 1st 1999. Comparing with the existing communication system, the new system is mainly based on the latest scientific technologies, and therefore overall countermeasure will be necessary to accept the system reasonably. GMDSS will transform the current communication system basically and be the major factor to change the demand and supply of personnel for radio communication. To cope with the system assertively, regulations relating to the radio installation, the posting of radio operators, the bounds of their duty, etc. must be established and the demand and supply of radio operators to meet the system must be accomplished pertinently. Moreover, the technique and quality of the person-nel responsible for the system must be upgraded to carry out the obligations by international regulations as well as to ensure the safety of life and property at sea. Looking into the actual situations of our country, every regulation relating to the GMDSS has been improved, but the concerned educational institutions and administrations have not yet prepared the rational and concrete schemes on the educational methods and adquate procedures for the system. Therefore, in this thesis, the author intends to propose directions for improving the courses and contents of education of the relating educational institutions and to suggest rational schemes for balancing the demand and supply of personnel to the administrative anthorty concerned.

• 한국산학기술학회논문지
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• 제19권8호
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• pp.535-544
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• 2018

다양한 센서를 내장하고 고품질의 무선 네트워크 통신 기능을 탑재한 이동 장치의 보급이 확대됨에 따라 다양한 서비스 환경에서 이동 장치로부터 생성되는 시공간 데이터 량도 빠르게 증가하고 있다. 이와 같이 실시간 특성을 갖는 대량의 공간 데이터 스트림을 처리하기 위한 기존의 연구에서 하둡 기반의 공간 빅 데이터 시스템은 일괄 처리 방식의 플랫폼으로 공간 데이터 스트림에 대한 실시간 서비스에 적용하기에는 매우 어렵다. 이에 본 논문에서는 맵리듀스 온라인 프레임워크를 확장하여 연속적으로 입력되는 공간 데이터 스트림에 대한 실시간 질의 처리를 지원하고, 질의 처리 과정에서 야기될 수 있는 부하 문제를 효과적으로 분산하는 부하 관리 기법을 제안한다. 제안 기법에서는 공간 분할 영역을 기반으로 입력 데이터의 유입율과 부하율을 이용하여 노드들에 대해 동적으로 부하를 분산하는 기법을 제시하였다. 실험에서는 특정 공간 영역에서의 부하 관리가 요구될 때 해당 영역에서의 공간 데이터 스트림을 공유하는 자원들에게 분배함으로써 효과적인 질의 처리를 지원할 수 있음을 보인다.

• 한국물환경학회지
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• 제23권5호
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• pp.766-775
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• 2007

The use of toxic chemicals was extended as the industry in Korea has grown dramatically during the last three decades. However, list of toxic substances and limit concentrations in the water environment are not consistent within management of ambient water, drinking water and industrial effluent. This article suggests the systematic framework to classify toxic substances in the water environment and deriving their effluent limits. The most important factor for decision-making to classify toxic substances is whether their concentrations in the water environment are higher than the reference concentrations, estimated by considering human health risk and ecological risk. Using a risk-based reference concentration, the ambient water quality criterion, it is possible to derive the regulatory limit concentrations of toxic substances in drinking water and in industrial effluent. The goal concentrations in the effluent, which guarantee the human and ecological safety, should be determined with scientific investigation, balancing environmental benefit and economical effect, considering availability of treatment technology and identifying characteristics of wastewater from different industries.

• Journal of Oral Medicine and Pain
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• 제19권2호
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• pp.181-192
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• 1994

There have been many different theories on the etiology of temporomandibular disorders(TMDs). The objective of the study was to investigate the effects of occlusal fctors and recent life event changes as prediposing fctor on the development of temporomandibjlar disorders. To evaluate the above predisposing factor, the author used T-scan system(Tekscan Co. U.S.A.) for quantitative occlusal analysis, clinical examination for occlusal state and Social Readjustment Rating Scale(SRRS) for recent life event change units (LCU). 63 patients with TMDs and 57 patients with malocclusion presented at Wonkwang University Dental Hospital participated in this study. The subjects were grouped by Angle's classification and presence of absence of TMDs and parafunctional oral habits. Data gained with regard to contact number, contact force, contact time, occlusal state(number of total teeth and occluding teeth, overjet, overbite) and occlusal interferences (protrusive posterior contact, nonworking side interference, and RCP-ICP slide) and recent life event changes. The data were processed and analysed by SAS statistical package program, The results of this study were as follows : 1. There were no significant differences on both quantitative occlusal contact analysis and occlusal state between TMDs group and Angle's malocclusion group. Also, there were no differences among the Angle's classifications. But amount of overjet in TMDs group were more greater than that of malocclusion group. 2. There was no difference on protrusive posterior contact, and balancing contact between TMDs group and Angle's malocclusion group. Premature contact was more frequent in malocclusion group, but RCP-ICP slide was more frequent in TMDs group. And RCP-ICP slide was more freqent in Angle's class II malocclusion than Angle's I or III malocclusion. 3. Life changes units in TMDs group were higher than those in malocclusion group. And recent life change units in group with parafunctional oral habit were higher than those in group without parafunctional oral habits. Clenching was the most common habit among parafunctional oral habits.

• Progress in Superconductivity
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• 제7권1호
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• pp.6-10
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• 2005

We have studied feasibility of single-layer second-order $high-T_c$ SQUID gradiometers in magnetocardiography. We have measured human cardiomagnetic signals using a short-baseline (5.8 mm) single-layer second-order YBCO gradiometer in partially shielded environments. The gradiometer has an overall size of $17.6\;mm{\times}6\;mm$ and contains three parallel-connected pickup coils which are directly coupled to a step-edge junction SQUID. The gradiometer showed an unshielded gradient noise of $0.84\;pT/cm^2/Hz^{1/2}$ at 1 Hz, which corresponds to an equivalent field noise of $280\;fT/Hz^{1/2}$. The balancing factor was $10^3$. Based on the same design rules as the short-baseline devices, we have studied fabrication of 30 mm-long baseline gradiometers. The devices had an overall size of $70.2\;mm{\times}10.6\;mm$ with each pickup coil of $10\;mm{\times}10\;mm$ in outer size. As Josephson elements we made two types of submicron bridges, which are variable thickness bridge (VTB) and constant thickness bridge (CTB), from $3\;{\mu}m-wide$ and 300 nm-thick YBCO lines with a thin layer of Au on top by using a focused ion beam (FIB) patterning method. VTB was 300 nm wide, 200 nm thick, 30 nm long with Au removed and CTB 100 nm wide and 30 nm long. In temperature-dependent critical currents, $I_c(T)$, VTB showed an nonmetallic barrier-type behavior and CTB an SNS behavior. We believe that those characteristics are ascribed to naturally formed grain boundaries crossing the bridges.

• 한국환경보건학회지
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• 제36권4호
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• pp.337-341
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• 2010

The modified simultaneous differential staining technique, which enables double staining of cartilage and bones, needs to be improved to prevent soft tissues from being damaged during the staining process. Key factors influencing the extent to which soft tissues are damaged include the fixative used, macerating time, potassium hydroxide concentration, incubation temperature and the removal of skin from specimens. Here we describe a protocol that enables the hardening of tissues during bleaching and maceration. We also describe a method for objectively measuring rates of cartilage and bone growth. The use of formalin as a fixative rendered soft tissues more rigid due to the resulting chemical bonds formed between proteins. Blotted specimens were immersed in 1% potassium hydroxide (KOH) and incubated at $37^{\circ}C$ for 1 day (smaller specimens) or 2-3 days (larger specimens). The 1% KOH solution was also used as the diluent solution for the subsequent immersion in a graded series of 30%, 50%, 70%, 90%, 100% glycerol solutions, a procedure that made soft tissues even more transparent and hardened. It was not necessary to remove the skin of specimens shorter than 2 cm, since the macerating solution could easily penetrate their thin skin layer and continuously remove those pigments hindering visibility. Since excessive osmosis is another factor that can damage soft tissues in the macerating process by causing the rupture of those cells not able to withstand the osmotic pressure, here it was minimized by balancing the salt concentration between the interior and exterior of cells with the addition of 0.9% sodium chloride (NaCl) in the macerating solution. Finally, to determine the proportions of cartilage and bone growth, photographs of the stained specimens were taken with a dissecting microscope and sections corresponding to the cartilage and bones were cut out from the printed pictures and weighed. Our results show that this method is suitable for the objective evaluation of bone and cartilage growth.

• 보건교육건강증진학회지
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• 제27권1호
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• pp.21-34
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• 2010

Objectives: The objective of this study was to investigate risk factors for falls in the elderly by life-cycle. Methods: This study used the data on 435 male and female elderly generated from a survey taken at 21 Welfare Centers for the Elderly in Seoul. The incidence of demographic characteristics, physical changes brought about with ageing, health-related behavior, chronic diseases, and environmental characteristics on falls in the elderly was analyzed. Hierarchical Logistic Regression analysis was also conducted to investigate the incidence by life-cycle (early-mid-late stage) and the results were used for predicting falls. Results: The incidence of risk factors on falls varied across life-cycle. Among the elderly in the early (ages from 65 through 74), marital status, the existence of a companion, the quality of sleep, the chronic diseases, and the condition of the bathroom floor were found to be related to falls. Among those in the mid-stage (ages from 75 through 84), sex, marital status, the existence of a companion, hearing capacity, sense of balancing, chronic diseases, the exclusive use of rooms, and the side bar with bath tub were found to affect falls. Finally, for the elderly in their late stage (85 years of age and older), drinking and vision were found to be related to falls. Conclusion: The incidence of risk factors on falls was found to vary according the stage in the elderly. A key implication of this finding is that falls prevention programs and interventions must be catered to specific age sub-groups.

• 한국과학교육학회지
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• 제35권4호
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• pp.585-598
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• 2015

본 연구는 예비 과학교사들의 집단 글쓰기 활동을 통해 집단 글쓰기 과정의 3단계인 정보수집, 정보의 논리적 조직, 검토 단계에서 나타나는 하위요소를 파악하고자 하는데 목표를 두고 있다. 이를 위하여 과학교과 논리 및 논술을 수강하는 19명의 예비 과학교사들을 대상으로 집단 글쓰기 수업을 구성하여 그 과정을 탐색하였다. 집단 글쓰기는 예비 과학교사들로 하여금 과학과 관련된 사회적 쟁점들 중 하나를 선택하여 작성하도록 하였으며, 4~5명으로 형성된 집단을 구성하여 실행되었다. 집단 글쓰기 3단계의 하위요소 분석은 집단별 토의내용과 작성한 글을 대상으로 귀납적으로 분석하여 결과를 도출하였다. 연구결과, 예비 과학교사들의 집단 글쓰기 과정의 3단계에서 다음과 같은 하위 요소가 추출되었다. 정보수집 단계에서는 정보 공유, 정보이해, 정보판별의 하위요소가 추출되었으며, 정보의 논리적 조직 단계에서는 정보의 범주화, 분산, 정보의 균형화, 성찰이라는 하위요소가 분석되었다. 마지막으로 검토 단계에서는 글 형식 통일, 전체적 글의 흐름검토, 가독성 고려라는 하위요소가 추출되었다.