• 대한치과교정학회지
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• 제47권5호
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• pp.298-305
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• 2017

Objective: This paper describes changes in the characteristics of patients seeking orthodontic treatment over the past decade and the treatment they received, to identify any seasonal variations or trends. Methods: This single-center retrospective cohort study included all patients who presented to Seoul National University Dental Hospital for orthodontic diagnosis and treatment between January 1, 2005 and December 31, 2015. The study analyzed a set of heterogeneous variables grouped into the following categories: demographic (age, gender, and address), clinical (Angle Classification, anomaly, mode of orthodontic treatment, removable appliances for Phase 1 treatment, fixed appliances for Phase 2 treatment, orthognathic surgery, extraction, mini-plate, mini-implant, and patient transfer) and time-related variables (date of first visit and orthodontic treatment time). Time series analysis was applied to each variable. Results: The sample included 14,510 patients with a median age of 19.5 years. The number of patients and their ages demonstrated a clear seasonal variation, which peaked in the summer and winter. Increasing trends were observed for the proportion of male patients, use of non-extraction treatment modality, use of ceramic brackets, patients from provinces outside the Seoul region at large, patients transferred from private practitioners, and patients who underwent orthognathic surgery performed by university surgeons. Decreasing trends included the use of metal brackets and orthodontic treatment time. Conclusions: Time series analysis revealed a seasonal variation in some characteristics, and several variables showed changing trends over the past decade.

• 대한추나의학회지
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• 제1권1호
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• pp.45-53
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• 2000

Objectives : CHUNA therapy that removes compression of dislocated vertebral bones has positive effect, but sometimes improper CHUNA manual therapy may give rise to negative effect. The aim of this study is to make sure that cervical CHUNA manual therapy give positive effect or negative effect to the blood flow velocity of vertebral artery(VA) and basilar artery(BA) by Trancranial Doppler sonography(TCD). Methods : We performed TCD study on 20patients(male 5, female 15, mean ages 38.5 years) with diagnosis like cervical movement related disorder, headache or dizziness. After we measured mean blood flow velocity(Vm) of VA and BA before cervical CHUNA therapy(Pre-CCT) and after cervical CHUNA therapy(Post-CCT), statistically evaluated the results. Results: The patients received cervical CHUNA therapy for TA sequel, HIVD of cervical spine, headache, dizziness, neck stiffness etc. VA Vm was $31.9{\pm}8.0cm/sec$ before CHUNA therapy, but significantly increased $35.0{\pm}8.7cm/sec$ after CHUNA therapy (p < 0.05). But, there was no significant variation of BA Vm between $41.8{\pm}7.5cm/sec$ Pre-CCT and $41.2{\pm}8.5cm/sec$ Post-CCT(p>0.05). Though VA Vm slightly increased after CHUNA therapy in normal range group, there was no significant variation between VA Vm Pre-CCT and VA Vm Post~CCT. In VA Vm decrease group, VA Vm significantly increased after CHUNA therapy(p<0.05). But, there was no significant variation of BA Vm between Pre-CCT and Post-CCT in BA Vm normal range group and BA Vm decrease group(p>0.05). Conclusions: These findings suggest that cervical CHUNA manual therapy have positive effect on blood flow velocity of VA and BA.

• 대한치과의사협회지
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• 제51권1호
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• pp.39-45
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• 2013

Radiographic examinations are used to discover and define the type and extent of disease in many clinical situations. Currently, it is common for dental patients to receive dental radiographic examinations on a routine schedule with little variation in spite of different patient signs and symptoms. Such routine scheduling of radiographic examinations may result in unnecessary patient exposure. There is also the possibility of under-utilization of radiography; this can result in inadequate or excessively delayed diagnosis. Patient selection criteria are descriptions of clinical conditions derived from patient signs, symptoms and history that identify patients who are likely to benefit from a particular radiographic examination. It makes possible making individual decisions based on history, clinical examination and risk factors. The radiographic selection criteria of dentistry have been revised in accordance with recent guidelines and peer-reviewed research in USA and Europe, but the studies of these subjects are not sufficient in our nation. In this review article, the relating factors and update necessity of radiographic selection criteria are discussed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2691-2696
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• 2011

THE CARBODY AND BOGIE FRAME OF AN URBAN RAILWAY VEHICLE CONSIST OF MULTI-LAYERED WELDING STRUCTURE. IN KOREA ENDURANCE LIMIT OF AN URBAN RAILWAY VEHICLE IS STSTED IN THE RULE OF MANAGING URBAN RAILWAY VEHICLE UNDER THE LAW OF URBAN RAILWAY. IN KOREA AN URBAN RAILWAY VEHICLE IS DESIGNED AND MADE TO KEEP ITS QUALITY OVER 25 YEARS. WHEN THE RAILWAY VEHICLE BECOMES 25 YEARS OLD, CORROSION OF CARBODY AND UNDER FRAME OF A RAILWAY VEHICLE IS EVALUATED ACCORDING TO THE NON-DESTRUCTIVE TESTING. IT CAN BE USED AS LONG AS 40 YEARS. IT IS STATED IN THE ARTICLE 4 'THE METHOD AND STANDARDS OF PRECISE DIAGNOSIS' UNDER THE RULE OF MANAGING RAILWAY VEHICLE IN KOREA. SO, IN THIS STUDY, WE HAVE INVESTIGATED PERFORMANCE OF PULSED EDDY CURRENT TESTING METHOD BY MEASURING THICKNESS VARIATION OF FABRICATE OF CARBODY AND UNDER FRAME FOR URBAN RAILROAD CAR. AND THEM, THE PROCESS OF EVALUATING REMAINING LIFE ACCORDING TO TESTING OF CORROSION AMOUNT IS INTRODUCED.

• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.367-384
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• 2002

Cerebral palsy refers to the neuromuscular deficit caused by nonprogressive defect or lesion in single or multiple locations in the immature brain resulting in Impaired motor function and sensory integrity. The pathophysiological events may occur during the prenatal intrapartum, perinatal, or early postnatal period. Cerebral palsy is the most common condition and it poses a challenge to practitioners due to the large variation in prognosis for motor function of children with this diagnosis. The objectives of this article are review to pathological and psychological factors of cerebral palsy and upper extremity function. Upper extremity and hand function are most important in activity of daily living in cerebral palsy This article hope to give the information for application in many therapists.

• 한국정밀공학회지
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• 제22권3호
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• pp.123-129
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• 2005

The unbalance of the power output, noise, and vibration is happened by the disproportionate pressure variation in the cylinder. For this reason, decrease of the pressure in the cylinder and increase of the residual gas effect on the engine performance. If the abnormal combustion is continued, the crack would be occurred in the engine block. And it could be broken down. For the normal combustion of the SI engine, it is important to supply the balanced mixture by each operating condition. In this study, it was tested the combustion characteristics in the cylinder according to the abnormal adjusting of intake & exhaust valve. This test is willing to set a basic data's analysis fur developing an automotive diagnosis system by analyzing the pressure in the cylinder, the output signal of MAP sensor, the exhaust gas, etc.

• 한국정밀공학회지
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• 제15권10호
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• pp.103-112
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• 1998

The evolution of semiconductor manufacturing technology has accelerated the reduction of device dimensions and the increase of integrated circuit density. In order to improve yield within a short turn around time and maintain it at high level, a system that can rapidly determine problematic processing steps is needed. The statistical process control detects abnormal process variation of key parameters. Expert systems in SPC can serve as a valuable tool to automate the analysis and interpretation of control charts. A set of IF-THEN rules was used to formalize knowledge base of special causes. This research proposes a strategy to apply expert system to SPC in semiconductor manufacturing. In analysis, the expert system accomplishes the instability detection of process parameter, In diagnosis, an engineer is supported by process analyzer program. An example has been used to demonstrate the expert system and the process analyzer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.414-417
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• 1999

According to development of power electric technology from industrial field to electronic home appliances, recent SMPS using semiconductor is spread widely. Electric converting instrument uses a sine wave voltage source, namely an usual power source, and it gets a non-sines power source from power source because current flows through one part in waveform of one cycle. This injects higher harmonic source in source part, absorb pollution source. And this cause quality deterioration, durability shortage of electric power instrument, spreading accident of electric solver system, and so on. It can't supply an electric source of good quality in industry, so become an impedimental element in improving productivity and reliance. This study can be used in prediction of hindrance and diagnosis material and intends to suggest a countermeasure about measurement data.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.274-278
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• 2022

One marine ciliate, Diophrys quadrinucleata Zhang et al., 2020 was newly recorded from South Korea in this study. We provided morphological diagnosis and images of the Korean D. quadrinucleata population. We determined the small subunit ribosomal DNA (SSU rDNA) and cytochrome oxidase subunit I (CO1) sequence data of D. quadrinucleata, and then the sequences were compared with other Diophrys species. Intra-specific variation between the Korean and type (Chinese) populations was identical in the SSU rDNA, while the inter-specific variations between seven Diophrys species were 0.3-3.8% in the SSU rDNA and 12.6-18.2% in the CO1. In this study, we obtained 18S and CO1 data from species with identified morphology. As the importance of securing 18S and CO1 based on morphology increases in current studies, this study will contribute to ciliate studies.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권11호
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• pp.508-511
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• 2003

In this paper, electrical characteristics of inductively coupled plasma in an electrodeless fluorescent lamp were investigated using a Langmuir probe with a variation of argon gas pressure. The RF output was applied in the range of 5 ∼ 50 (W) at 13.56 (MHz). The internal plasma voltage of the chamber and the probe current were measured while varying the supply voltage to the Langmuir probe in the range of -100 (V) ∼+100 (V). When the pressure of argon gas was increased, electric current was decreased. There was a significant electric current increase from l0W to 30 〔W〕. Also, when the RF power was increased, electron density was increase. This implies that this method can be used to find an optimal RF rower for efficient light illumination in an electrodeless fluorescent lamp.