• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.1
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• pp.10-17
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• 1991

An improved control method in turbine control system is proposed. By automatic follow-up design, power system frequency may be maintained within prespecified range. Base or half load control is possible by distributing power plant load allotment. Otherwise, diminutive frequency-load control is dine by governor-free operation in power plant. This paper proposes governor-free operation which is automatically followed by load-limitter setter. The condition which limits governor action may be somewhat improved within boiler condition by this idea. This design has been implemented at Samchunpo thermal power plant. The improved practical results are shown.

• The Korean Journal of Cytopathology
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• v.9 no.1
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• pp.29-35
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• 1998

In 1988, The Bethesda System for reporting cervical and vaginal cytologic diagnoses was introduced and this was revised in 1991. The new diagnostic category "atypical squamous cells of undetermined significance(ASCUS)" introduced by The Bethesda System is an area of controversy about the diagnostic category, clinical significance and appropriate treatment. A retrospective 2 years and 9 months study(April, 1994-December, 1996) was performed to evaluate the significance of reporting ASCUS on cervical smears. Sixtyseven(1.17%) of 5,730 smears were diagnosed as ASCUS and 21 cases were followed by cervical biopsies and/or endocervical curettages in 4 cases(19%), and repeat cervical smears in 17 cases(81%). Tissue diagnoses were benign in 2 cases and squamous cell carcinoma in situ in 2 cases. Cytologic diagnosis of follow up smear were negative in 14 cases(82.4%) and persistent ASCUS in 3 cases(17.6%).

• The Journal of Advanced Prosthodontics
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• v.1 no.3
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• pp.136-139
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• 2009

STATEMENT OF PROBLEM. Many dental clinicians are concerned about immediate loading of inserted implants. However, there have been few clinical studies surveying the success rates of immediate loading, based on Korean implant systems. PURPOSE. The aim of this study was to evaluate the outcome of immediate functional loading of the implant ($SinusQuick^{TM}$EB, Neobiotech Co., Seoul, Korea) in partially edentulous maxilla or mandible. MATERIAL AND METHODS. Total 15 implants were placed. Within 2 weeks after implant insertion, provisional implant-supported fixed partial dentures were delivered to the patients. Quantitatively, marginal bone loss was measured at the time of immediate loading, after 3-months of continued loading and at the last follow-up. The mean follow-up period was 4.8 months. RESULTS. Mean marginal bone loss from implant surgery to early loading, 3-months follow-up and last follow-up was $0.03\pm0.07$ mm, $0.16\pm0.17$ mm and $0.29\pm0.19$ mm. No implant failed up to 6 months after insertion, resulting in a 100% survival rate. CONCLUSION. Immediate loading exhibited high success rate in partial edentulism for up to 6 months. Well-controlled long term clinical studies with large sample size are necessary to confirm this finding.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2711-2717
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• 2016

Background: Through search the possible randomized control trials, we make a renewed meta-analysis in order to assess the impact of aspirin in preventing the recurrence of colorectal adenoma. Materials and Methods: The Medicine/PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese biomedical literature service system (SinoMed) databases were searched for the related randomized controlled trials until to the April 2016. Three different authors respectively evaluated the quality of studies and extracted data, and we used the STATA software to analyze, investigate heterogeneity between the data, using the fixed-effects model to calculate and merge data. Results: 7 papers were included the renewed meta-analysis, among these studies, two pairs were identified as representing the same study population, with the only difference being the duration of follow-up. Thus there were only five papers included our meta-analysis, and one Chinese paper were also included the work. Results were categorized by the length of follow-up, different kinds of people, varied dose of oral aspirin. The relative of adenoma in patients taking aspirin vs placebo were 0.73 (95% CI 0.55-0.98, P=0.039) with 1 year follow up; 0.84 (95% CI 0.72-0.98, P=0.484) with greater than 1 year follow up; for the advanced adenoma, the RR 0.68 (95% CI 0.49-0.94, P=0.582),for one year; RR=0.75 (95% CI 0.52-1.07, P=0.552) for greater one year. Furthermore the white population could divided into two subgroups according to the different length of follow-up time. When the length of follow-up time less than 3-year, The RR of two subgroups respective were RR=0.86 (95% CI 0.76-0.98, P=0.332), $I^2=0%$, RR=0.68 (95% CI 0.47-0.98, P=0.552), $I^2=64.6%$, But with the extension of follow-up time greater than 2-year, with the white, oral aspirin without considering dose had no efficacy on preventing the recurrence of any adenoma, the RR was 0.86 (95% CI 0.71-1.05, P=0.302), $I^2=16.4%$. Conclusions: This meta-analysis indicated that oral aspirin is associated with a remarkable decrease in the recurrence of any adenoma and advanced adenomas in patients follow-up for 1 year without concerning the dose of aspirin, but with the extension of follow-up time for greater than 1 year, oral aspirin can be effective on preventing the recurrence of any adenoma, but for the advanced adenoma, the result indicated that oral aspirin had no efficacy, According to the inclusion of ethnic groups, we also divided relevant papers into two subgroups as the yellow and white group. Then the follow-up time was less than 3 years, oral aspirin without considering the dose, had an significant efficacy on preventing the recurrence of any adenoma. But with the follow-up greater than 2 years, oral aspirin had no effect in the white.

• Journal of Preventive Medicine and Public Health
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• v.40 no.2
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• pp.162-168
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• 2007

Objectives : This prospective population-based cohort study was conducted to evaluate the risk factors of cognitive impairment and the degree of cognitive function change through a 5-year follow-up. Methods : The baseline and follow-up surveys were conducted in 1998 and 2003, respectively, Among 176 subjects who had normal cognitive function in the baseline study, 136 were followed up for 5 years. The cognitive function was investigated using the Korean version of the Mini-Mental State Examination (MMSE-K). The collected data were analyzed using SPSS and Stata. Results : Of the 136 subjects analyzed, 25 (18.4%) were cognitively impaired. Old age and low social support in the baseline survey were risk factors for cognitive impairment after 5 years. In the generalized estimating equation for 128 subjects except severe cognitive impairment about the contributing factors of cognitive function change, the interval of 5 years decreased MMSE-K score by 1.02 and the cognitive function was adversely affected with increasing age, decreasing education and decreasing social support. Conclusions : Although the study population was small, it was considered that the study results can be used to develop a community-based prevention system for cognitive impairment.

• Clinics in Shoulder and Elbow
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• v.21 no.2
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• pp.59-66
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• 2018

Background: Massive, irreparable rotator cuff tears (RCTs) are a challenging clinical problem in young patients. In recent years, arthroscopic superior capsular reconstruction (ASCR) is a popular treatment in the massive, irreparable RCTs. However, studies reporting clinical results of ASCR are rare in the literature. Methods: Between 2013 and 2015, six patients underwent ASCR. One patient treated with dermal allograft, while five patients with autogenous fascia lata graft. Demographic data, as well as preoperative and last follow-up clinical data including pain, range of motion (ROM), strength, American Shoulder and Elbow Surgeons system, the Constant system, the University of California at Los Angeles system, the Simple Shoulder Test, and the Shoulder Pain and Disability Index system were obtained. Acromiohumeral distances and Hamada classification were measured on standard anteroposterior x-ray. Results: All patients were men, and the average age was $59.5{\pm}4.18years$ (range, 53-65 years).The minimum follow-up was 18 months with a mean follow-up was $27.33{\pm}7.58months$ (range, 18-36). All patients had postoperative improvement in pain scores and functional scores. The ROM and strength did not improve after surgery. The Hamada score progressed of radiographic stage in 2 patients. In the case of dermal allograft, there was graft failure 6 weeks after ASCR. Conclusions: Our results support the ASCR as a viable treatment for surgical salvage in massive, irreparable RCTs. This treatment option may provide patients with decreased pain and increased function. And studying our case of dermal allograft failure provides opportunities to decrease graft failure in ASCR using dermal allograft.

• Journal of Korean Society of Rural Planning
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• v.25 no.2
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• pp.99-117
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• 2019

Environmental impact assessment (EIA), which predicts, evaluates, and manages the influences on natural landscape, plays a role of monitoring natural resources for systematic management of natural landscape. However, the function of verification and correction of the system is still insufficient and feed-back, one of the most important features of EIA follow-up, has not been introduced in Korea's EIA system yet. As a procedure, it is required to check if the opinions of the evaluators are properly reflected to the outcomes of the project through a reviewing process after assessing environmental impacts of a development project. In reality, despite the awareness about the importance of follow-up inspection of the conformity with, the system mainly focuses on the agreement during the planning stage of the development project and fails to continuously manage after its completion. There have been various preceding studies related to prediction, evaluation, and management of environmental impacts on natural landscape for better management. They primarily dealt with the problems in the EIA process and suggested improvement measures, including directions for institutional development, step-by-step goals, and operation methods, to address the problems which arise in the EIA follow-up process. However, suggested measures are not actively applied with the focus only put on institutional operation, there are virtually no standardized methods to predict and assess landscape changes due to the development project and to manage landscape after the project. Against this backdrop, this study aims to explore the existing methods to analyze the impacts natural landscape and to establish a system where landscape management is continued after the development project. To this end, we will suggest reducing methods according to the predicted changes in landscape for post-project management of natural landscape. Characteristics of reduction methods by project type were examined through reviewing the guide to natural landscape rating and the importance of development project impacts on natural landscape by type of reduction was evaluated through questionnaire for experts. Evaluated types of reduction are classified and presented by characteristics of each development project and content of reduction type.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.7
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• pp.272-277
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• 1986

The system that follows to the resonance frequency of high frequency MOSFET inverter and varies according to the changes of load characteristics is proposed. Also we suggested a method how to select the resonant load type between series and parallel circuit for a given inverter type. It leads to the conclusion that in the case of high impedance loads, parallel resonant circuits are preferable, on the other hand, for low impedance loads, series resonant circuits are more preferable. For frequency tracking, a PLL circuit is used as main control element to detect the phase difference of current and voltage of load. The realized apparatus composed of control circuit and voltage type full-bridged MOSFET elements as main parts of inverter. A stable frequency follow-up characteristics are obtained for 1.2MHz, 1.5KW high frequency output and power is always supplied to the load with unity power factor.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.543-556
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• 2000

A study on Technical Specifications of the current collection system in G7 Korean High Speed Train Project is performed in this paper. First, an appropriate level of contact wire tension for 350km/h commercial operation is proposed based on the foreign high speed train operation experiences and a relevant technical criterion, Second, two optimized design specifications of the pantograph for G7 Korean High Speed Train are proposed based on current collection quality. In order to perform design optimization, a formulation on the follow-up characteristics of a pantograph with 3 levels of masse-spring-damper is derived in this paper. Dynamic design parameters of the pantograph are adjusted to maximize follow-up capability at the dropper and span passing frequencies.

• 대한치과보철학회:학술대회논문집
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• 2001.04a
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• pp.54-54
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• 2001