• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.2
• /
• pp.323-330
• /
• 2004

The purpose of this study was to evaluate the diagnostic validity of early proximal caries lesions using laser fluorescence and whether the detection could be enhanced using a fluorescent dye. Direct visual examination and bitewing radiograph were used for comparison. The subjects of this study were 30 children of $3{\sim}9$ years old. Laser fluorescence and dye-enhanced laser fluorescence(mixed wavelength of 488 and 514 nm) were used and viewed through glasses(excluding wavelength<520 nm). For dye-enhanced laser fluorescence a 0.075% sodium fluorescein dye was applied before examination. Proximal caries lesion of each subject was assessed using visual examination, bitewing radiograph, laser fluorescence, and dye-enhanced laser fluorescence. The results in the three detection methods were compared to the assessment of bitewing radiograph. The results from the present study can be summarized as follows: 1. There was highly correlation(r=0.725-0.911) between the bitewing radiograph and all three detection methods(p<0.05) 2. The reproducibility(kappa value) of the visual examination, laser fluorescence and dye-enhanced laser fluorescence comparing with bitewing radiograph of proximal caries was 0.451, 0.683, 0.772, respectively. There was highest correlation between dye-enhanced laser fluorescence and bitewing radiograph for detection of proximal caries. The results from this study indicated that the dye-enhanced laser fluorescence considered to be accurate and reliable method in detecting proximal caries.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.38 no.1
• /
• pp.9-17
• /
• 2022

Purpose: The purpose of this study is to investigate how open contacts impact the natural teeth and dental implant prostheses. Materials and Methods: Following criteria were used to select 20 implant crowns with open proximal contacts as the experimental group (Group A): the restorations were delivered in Chosun University Dental Hospital between 2008 and 2018, the restorations are in the posterior region, opposing teeth are fixed dental prostheses, neighboring teeth are sound natural teeth, the patient had been on the maintenance program for at least 3 years. Another 20 implant crowns with closed proximal contacts were selected as the control group (Group B) using the same criteria. Between the two groups, dental caries and food impaction of the neighboring natural teeth and marginal bone-loss of the implants were compared and evaluated. Results: There was no statistically significant difference between Group A and Group B in the occurrence rates of dental caries, food impaction, and marginal bone-loss. The amount of marginal bone-loss, however, revealed statistically significant differences between the two groups, with Group A showing 0.80 ± 0.39 mm loss and Group B showing 1.1 ± 0.43 mm loss. Conclusion: Implant prostheses with open contacts could be clinically considered in select cases as such restorations revealed no harmful effects on neighboring teeth and implant restorations within the perimeters of this study.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.3
• /
• pp.669-676
• /
• 2023

This study analyzed the relationship between major parameters and numerical analysis results according to various excavations conducted around the urban railway, application of machine learning techniques and verified the scope of influence of the adjacent excavation on the existing urban railway box structure and the appropriateness of the safety area. This study targeted the actual negotiated adjacent excavation works and box structures around the urban railway, and the analysis was conducted on the most representative two-line box structures. The analysis confirmed that the difference in depth of urban railway, excavation depth of adjacent excavation, and depth of underground water level are important parameters, and the difference in excavation depth of adjacent excavation is the parameter that affects the behavior of underground box structures and is an important requirement for setting safety areas. In particular, the deeper the depth of the adjacent excavation work, the greater the effect on the deflection of the underground box structure, and the horizontal separation distance, one of the important requirements for determining the management grade of the existing adjacent excavation work, is relatively small.

• Journal of the Korean association of regional geographers
• /
• v.15 no.3
• /
• pp.317-327
• /
• 2009

The aim of this paper is to analyse survey data on the geomorphological landscape of demilitarized zone(DMZ) and borderland which are collected through the national pilot study of natural environment by the Ministry of Environment. In addition, it is to explore applications on analytic results. Of total 356 geomorphological landscapes, River terraces have the highest share of the total, and the first grade is 57 landscapes(16.1%). This survey is significant in that the geomorphological landscape of DMZ and borderland by being access to the Northern Boundary Line is explored. The landscape has the only spatial characteristic over the world because it is within DMZ, and there is a high possibility to use for a geopark which is selected by UNESCO.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.6
• /
• pp.488-494
• /
• 2014

Rocket Plumes can cause serious damage to launch vehicles and adjacent structures. This paper describes the impact of an adjacent structure by a rocket plume. Each parameter related with dynamic behavior of a missile is modeled with probabilistic distributions of variables. Flyout analyses of initial behavior of a vertically launched missile are performed using Monte-Carlo simulation and flow-motion analyses were conducted by using CFD. In this way, when a missile is fired by a ship, the impact of an adjacent structure by a rocket plume was analyzed.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.301.1-301.1
• /
• 2014

모바일 전자기기 시장의 큰 증가세로 인해 플래시 메모리 소자에 대한 수요가 급격히 증가하고 있다. 특히, 저 전력 및 고집적 대용량 플래시 메모리의 필요성이 커짐에 따라 플래시 메모리 소자의 비례축소에 대한 연구가 활발히 진행되고 있다. 하지만 10 nm 이하의 게이트 크기를 가지는 플래시 메모리 소자에서 각 셀 간의 간섭에 의한 성능저하가 심각한 문제가 되고 있다. 본 연구에서는 10 nm 이하의 낸드 플래시 메모리 소자에서 인접한 셀 간의 간섭으로 인해 발생하는 전기적 특성의 성능 저하를 관찰하고 메커니즘을 분석하였다. 4개의 소자가 배열된 낸드플래시 메모리의 전기적 특성을 3차원 TCAD 시뮬레이션을 툴을 이용하여 계산하였다. 인접 셀의 프로그램 상태에 따른 측정 셀의 읽기 동작과 쓰기 동작시의 전류-전압 특성을 게이트 크기가 10 nm 부터 30 nm까지 비교하여 동작 메커니즘을 분석하였다. 게이트의 크기가 감소함에 따라 플로팅 게이트에 주입되는 전하의 양은 감소하는데 반해 프로그램 전후의 문턱전압 차는 커진다. 플래시 메모리의 게이트 크기가 줄어듦에 따라 플로팅 게이트의 공핍영역이 차지하는 비율이 커지면서 프로그램 동작 시 주입되는 전하의 양이 급격히 줄어든다. 게이트의 크기가 작아짐에 따라 인접 셀 과의 거리가 좁아지게 되고 이에 따라 프로그램 된 셀의 플로팅 게이트의 전하가 측정 셀의 플로팅 게이트의 공핍영역을 증가시켜 프로그램 특성을 나쁘게 한다. 이 연구 결과는 10 nm 이하의 낸드 플래시 메모리 소자에서 인접한 셀 간의 간섭으로 인해 발생하는 전기적 특성의 성능 저하와 동작 메커니즘을 이해하고 인접 셀의 간섭을 최소로 하는 소자 제작에 많은 도움이 될 것이다.

• Journal of Korean Society for Geospatial Information Science
• /
• v.15 no.1 s.39
• /
• pp.17-22
• /
• 2007

In this study, we recognized and joined parts of buildings separated during LIDAR point segmentation utilizing scan line characteristics, with an additional function to recognize neighboring relation among point segments. And we applied the relation to suggest a method to recognize earth point segment. From the test, we could confirm that it does not drop down the efficiency of point segmentation to be added with the function of recognizing neighboring relation and it is possibile to combine point segments to form a complete shaped building and to recognize earth point segment.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.26 no.2
• /
• pp.197-204
• /
• 2010

The purpose of the study was to observe the time serial changes in proximal contact tightness after single crown restoration. Initial proximal contact tightness before crown preparation and after prosthesis restoration were measured repeatedly in 12 subjects. In consequence proximal contact tightness of temporary setting on prosthesis was bigger than contact tightness before initial preparation, contact tightness of the prostheses of 1-2 weeks after the setting was similar to that before the preparation, tightness of 2-4 weeks after the setting showed little change and maintained constant contact tightness.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.8C
• /
• pp.771-778
• /
• 2003

A mobile station in a cell receives interference signals from neighboring base stations. Due to the interference signals, the forward link capacity of the cellular system is reduced. Pilot signal received from a neighboring base station is one of the interference signals. Since the pilot signal is a known signal for all the mobile stations, the pilot interference signal can be cancelled by interference cancellation techniques. In this paper, we propose a demodulator with interference canceller to cancel pilot interference signals received from neighboring base stations. The simulation results show that Eb/No value to obtain BER = 10-2 is lowered by 3㏈ in the propose demodulator.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.280-283
• /
• 2010

척추경 나사못을 이용한 요추 유합술은 가장 보편적으로 사용되는 수술 적 치료 방법이다. 과거 여러 연구들에서 이러한 척추 유합술의 임상적 우수성은 이미 입증 되었으며, 척추경 나사못은 시술 부위의 운동을 완전히 제한함으로써 높은 유합율을 얻을 수 있으나, 상대적으로 인접 분절의 조기 퇴행성 변화의 요인 중 하나로 보고되고 있다. 또한 유합술을 수행 할 때 후방조직의 절제 또한 인접 분절의 퇴행을 초래하는 원인으로 보고되고 있다. 따라서 본 연구에서는 유한요소해석 방법을 이용하여 척추경 나사못 과 후방조직을 절제하는 시술 방법을 비교하여 척추체의 운동범위의 증가량을 계산하였고, 척추경 나사못 모델과 후방조직을 제거한 모델을 개발하여 시술하기 전 정상모델과 비교하였다. 개발된 모델과 정상 모델을 생체 역학적 측면에서 분석하여 인접분절의 조기 퇴행성 변화를 일으키는 가장 큰 원인이 무엇인지 정량적으로 분석하였고, 이를 근거 하여 임상적 효과와 그 이론적 근거를 제시하고자 한다.