• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.95-101
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• 2003

The purpose of this study was to evaluate the patterns of skeletal changes of proximal and distal segments after one jaw surgery and two jaw surgery with posterior impaction using SSRO on mandible in order to determine the skeletal origin of relapse and compare the stability of surgical methods in anterior open bite. The points and lines from lateral cephalometrics were measured before, after surgery, and at least 6-month follow up period. And then, the positional change of the proximal and distal segment were evaluated respectively. The results obtained were as follows; In cases of two jaw surgery, the results were stabler because they had less relapse factors. In cases of one jaw surgery, the value of APD were increased but it didn't relapse to the original value. Both of proximal and distal segments were responsible for the relapse tendency. But in one jaw surgery, the rotation of proximal segment was more responsible, and in two jaw surgery, the rotation of distal segment was.

• 전기학회논문지
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• 제65권4호
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• pp.659-665
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• 2016

In this paper, we propose a novel position accuracy enhancement method of a low-end GPS using digital map information. The latest digital map has various kinds of information on geographical features. The proposed method uses position information of lane marks among the geographical features. We define the position information of lane marks as the reference points. The position information of a low-end GPS acquired for a period of time is defined as the source points. In the proposed method, rotation and translation matrices between the reference and the source points are calculated by using an Iterative Closest Point(ICP) algorithm. The source points are transformed by the obtained rotation and translation matrices. Finally, the transformed source points are projected on the reference points. Through these processes, the position accuracy of a low-end GPS is ultimately enhanced. To verify the proposed method, the various real experimental results are presented.

• Journal of the Optical Society of Korea
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• 제17권5호
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• pp.357-361
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• 2013

A regenerative Er-doped fiber amplifier system for a high-repetition-rate optical pulse train is investigated for the first time. A signal pulse train with a wavelength tuning range of 18 nm is produced by a passive mode-locked fiber laser based on a nonlinear polarization rotation technique. In order to realize the amplification, an optical delay-line is used to achieve time match between the pulses' interval and the period of pulse running through the regenerative amplifier. The 16 dB gain is obtained for an input pulse train with a launching power of -30.4 dBm, a center wavelength of 1563.4 nm and a repetition rate of 15.3 MHz. The output properties of signal pulses with different center wavelengths are also discussed. The pulse amplification is found to be different from the regenerative amplification system for CW signals.

• PNF and Movement
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• 제15권1호
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• pp.97-104
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• 2017

Purpose: This study seeks to determine the effect of a lower extremity strengthening exercise that uses proprioceptive neuromuscular facilitation (PNF) on the gait and balance ability of a stroke patient. Methods: In this case study, a lower extremity strengthening exercise that used PNF was performed by the subject for 30 minutes 4 times per week for a 4-week period alongside typical rehabilitation therapy. The lower extremity pattern used flexion-abduction-internal rotation with knee flexion, extension-abduction-internal rotation, bilateral leg extension pattern. The 10 m walk test and 6 minute walk test were used to assess gait ability. The Berg balance scale was used to assess balance ability. Results: After the intervention, the time for the 10 m walk test decreased by 5.72 sec, the distance for the 6 minute walk test decreased by 20 meters, and the score on the Berg balance scale improved by 7 points, which indicates the effectiveness of this therapy for stroke patients. Conclusion: The results of this study indicate that a lower extremity strengthening exercise using PNF can improve the gait ability and balance ability of stroke patients.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권5호
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• pp.254-259
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• 2019

Objectives: Crown-root fracture and cervical caries in maxillary premolars constitute a challenge in cases of subgingival placement of restoration margins. Surgical extrusion has been practiced successfully in permanent anterior teeth. The aim of the present retrospective study was to assess the clinical outcome of surgical extrusion after orthodontic extrusion in maxillary premolars. Materials and Methods: Twenty-one single, tapered root maxillary premolars with subgingival crown-root fracture or caries were included. Presurgical orthodontic extrusion was performed on all teeth to prevent root resorption. Extent of extrusion and rotation was determined based on crown/root ratio. The postoperative splinting period was 7 to 14 days. Clinical and radiographic examination was performed at an interval of 1, 2, and 3 months. Results: After the mean follow-up of $41.9{\pm}15.2months$, failure was observed as increased mobility in 3 of 21 cases. No significant difference was observed in the outcome of surgical extrusion based on tooth type, age, sex, $180^{\circ}$ rotation, or time for extraction. Furthermore, marginal bone loss was not observed. Conclusion: Surgical extrusion of maxillary premolars can be a possible therapeutic option in cases of subgingival crown-root fracture.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.196.2-196.2
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• 2016

The design and development procedures of SF6 gas circuit breakers are still largely based on trial and error through testing although the development costs go higher every year. The computation cannot cover the testing satisfactorily because all the real processes arc not taken into account. But the knowledge of the arc behavior and the prediction of thermal plasmas inside SF6 interrupters by numerical simulations are more useful than those by experiments due to the difficulties to obtain physical quantities experimentally and the reduction of computational costs in recent years. In this paper, in order to get further information into the interruption process of a SF6 self-blast interrupter, which is based on the combination of thermal expansion and arc rotation, gas flow simulations with a CFD-arc modeling are performed during the whole switching process such as high-current period, pre-current zero period, and current-zero period. Through the complete work, the temperature of residual arcs as well as the breakdown index after current zero should be a good criterion to predict the dielectric capability of interrupters.

• 한국광학회지
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• 제15권5호
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• pp.409-414
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• 2004

본 논문에서는 광섬유 장주기 격자를 이용한 센서 신호처리 시스템을 구현하였다. SLD와 Fabry-Perot 필터를 이용한 동조 반도체 광원과 Fabry-Perot 필터내의 PZT의 히스테리시스 특성을 보상하기 위한 에탈론 필터를 사용하였으며, 절대적인 기준 파장을 제공하기 위하여 온도 안정화된 광섬유 브래그 격자를 사용하였다. 시스템에서 검출된 신호를 A/D 변환하여 컴퓨터로 입력하고 신호 처리하여 결과를 모니터상에 표시하였다.

• 한국지진공학회논문집
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• 제28권4호
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• pp.165-170
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• 2024

This study investigated the impact of soil-structure interaction on multi-degree-of-freedom structures using the shallow-foundation Winkler model, known as the BNWF model. The model's period was determined through eigenvalue analysis and compared to results obtained from FEMA's formula. Results indicated that considering the soil, the structure's period increased by up to 8.7% compared to the fixed-base model, aligning with FEMA's calculations. Furthermore, with adequate ground acceleration, roof displacement increased by 3.4% to 3.8%, while base shear decreased by 4% to 10%. However, roof displacement and base shear increased in some earthquake scenarios due to spectral shape effects in regions with extended structural periods. Foundation damping effects, determined through the foundation's moment-rotation history, grew with higher ground acceleration. This suggests that accounting for period elongation and foundation damping can enhance the seismic design of multi-degree-of-freedom structures.

• 한국안광학회지
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• 제18권4호
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• pp.449-456
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• 2013

목적: 렌즈 착용자의 자세가 변했을 때 각막이심률 및 각막형상이 토릭소프트렌즈의 회전 양상에 미치는 영향을 알아보고자 하였다. 방법: 각막난시 -1.00 D의 직난시를 가진 20대 남녀 41안의 이심률을 측정하고 전체난시량에 따라 토릭소프트렌즈를 피팅하였다. 정자세와 누운 자세일 때의 토릭소프트렌즈의 회전을 슬릿램프에 장착된 카메라를 이용하여 촬영하고 분석하였다. 결과: Accelerated stabilization 디자인의 토릭소프트렌즈는 이심률에 관계없이 대부분 누운 방향인 귀쪽으로 회전하였으며 이심률이 큰 경우와 비대칭나비형 각막에서는 코쪽으로 회전하는 경우도 있었다. 렌즈착용 직후 정자세와 누운 자세에서 회전양과 이심률은 상관관계가 없었으나 일정 시간동안 누운 자세로 있는 경우는 이심률이 큰 각막에서 회전양이 더 컸다. 회전속도는 누운 자세로 변화된 직후부터 속도가 감소하였으며, 이심률에 따른 큰 차이는 없었다. 누운 자세로 변화된 직후 대칭나비형과 비대칭나비형의 경우는 타원형 각막에 비해 회전양이 더 크게 증가하였으며 일정 시간이 지난 후에도 마찬가지였다. 누운 자세에서의 렌즈회전속도는 다른 각막형태에 비해 비대칭나비에서 가장 느렸다. 결론: 본 연구를 통하여 자세변화시 토릭소프트렌즈의 회전 양상은 각막이심률 및 각막형상에 의해 영향을 받는다는 것을 알 수 있었다. 따라서 토릭소프트렌즈 피팅 및 디자인 개발 시에 이에 대한 고려가 이루어져야 할 것으로 보인다.

• Clinics in Shoulder and Elbow
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• 제16권1호
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• pp.27-32
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• 2013

목적: 상완골 간부 단순 골절의 수술적 치료에서 잠김 압박 금속판을 이용한 최소 침습적 금속판 골유합술의 임상적 및 방사선학적 결과를 분석하였다. 대상 및 방법: 2010년 8월부터 2011년 5월까지 상완골 간부 단순 골절 골절에 대해 최소 침습적 금속판 골 유합술을 통해 수술을 시행하고 전향적으로 12개월 이상 추시한 6례의 환자를 대상으로 하였으며, 임상적 및 방사선학적 골유합 기간 및 술 후 관절 운동 범위와 기능을 확인하였다. 결과: 임상적 및 방사선학적 평균 골유합 기간은 각각 7.2주, 8주였다. 술 후 골 정렬에서 전후상 평균 2.8도, 측면상 내반 2도의 변형을 보였다. 술 후 12개월째 견관절 운동 범위는 전방거상 167도, 외회전 50도, 내회전 수위는 흉추 11번이었고, 평균 VAS는 1.2점, KSS는 91.3점, ASES는 26.5점, UCLA 점수는 31.5점이었다. 결론: 상완골 간부 단순 골절의 수술적 치료에서 최소 침습적 금속판 골유합술은 방사선학적 및 기능적으로 우수한 결과를 보였으며 상완골 간부 단순 골절에서 고려해 볼 수 있는 유용한 치료 방법 중 하나라고 생각된다.