• International Journal of Precision Engineering and Manufacturing
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• 제8권2호
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• pp.70-74
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• 2007

This paper describes the development of a nano-positioning system for nanoscale science and engineering. Conventional positioning systems, which can be expensive and complicated, require the use of laser interferometers or capacitive transducers to measure nanoscale displacements of the stage. In this study, a new self-displacement sensing (SDS) nano-stage was developed using mechanical magnification of its displacement signal. The SDS nano-stage measured the displacement of its movement using a position-sensitive photodiode (PSPD), a laser source, and a hinge-connected rotating mirror plate. A beam from a laser diode was focused onto the middle of the plate with the rotating mirror. The position variation of the reflected beam from the mirror rotation was then monitored by the PSPD. Finally, the PSPD measured the amplified displacement as opposed to the actual movement of the stage via an optical lever mechanism, providing the ability to more precisely control the nanoscale stage. The displacement amplification process was modeled by structural analysis. The simulation results of the amplification ratio showed that the distance variation between the PSPD and the mirror plate as well as the length L of the mirror plate could be used as the basic design parameters for a SDS nano-stage. The PSPD was originally designed for a total travel range of 30 to 60 mm, and the SDS nano-stage amplified that range by a factor of 15 to 25. Based on these results, a SDS nano-stage was fabricated using principle of displacement amplification.

• 방사선산업학회지
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• 제9권2호
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• pp.85-90
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• 2015

Purpose: Time of operation has been reduced and accuracy of operation has been improved since C-arm, which offer real-time image of patient, was introduced in operation room. However, because of the contamination of patient, C-arm could not be used more appropriately. Therefore, this study is to know factors of controlling exposure dose, image quality and the exposed dose of health professional in operation room. Materials and methods: Height of Wilson frame (bed for operation) was fixed at 130 cm. Then, Model 76-2 Phantom, which was set by assembling manual of Fluke Company, was set on the bed. Head/Spine Fluoroscopy AEC mode was set for exposure condition. According to detector size of C-arm, the absorbed dose per min was measured in the 7 steps OFD (cm) from 10 cm to 40 cm (10, 15, 20, 25, 30, 35, 40 cm). In each step of OFD, the absorbed dose per min of same diameter of collimation was measured. Moreover, using Nero MAX Model 8000, exposure dose per min was measured according to 3 step of distance from detector (20 cm, 60 cm, 100 cm). Finally, resolution was measured by CDRH Disc Phantom and magnification of each OFD was measured by aluminum stick bar. Result: According to detector size of C-arm, difference of absorbed dose shows that the dose of 20 cm OFD is 1.750 times higher than the dose of 40 cm OFD. It means that the C-arm, which has smaller size of detector, shows the bigger difference of absorbed dose per min (p<0.05). In the difference of absorbed dose in the same step of OFD (from 20 cm to 40 cm), the absorbed dose of 9 inch detect or C-arm was 1.370 times higher than 12 inch' s (p<0.05). When OFD was set to 20 cm OFD, the absorbed dose of non-collimation case was approximately 0.816 times lower than the absorbed dose of collimation cases (p<0.05). When the distance was 20 cm from detector, exposed does includes first-ray and scatter-ray. When the distance was 60 cm and 100 cm from detector, exposed does includes just scatter-ray. So, there was the 2.200 times difference of absorbed does. Finally, when OFD was increased, spatial resolution was 4 to 5 step was increased. However, low contrast resolution was not relative. Moreover, there was 1.363 times difference of magnification (p<0.05). Conclusion: When C-Arm is used, avoiding contamination of patient is more important factor than reducing exposed dose of health professional in operation room. Just controlling exposure time is just way to reduce the exposed does of workers. However, in the case, non-probability influence could be occurred. Therefore, this study proved that the exposed dose will be reduced if the factors such as using small detector size of C-arm, setting OFD from 20 cm to 25 cm and non-collimating. Moreover, dose management of C-arm in the non-interesting area will be considered additionally.

• 한국심리학회지 : 문화 및 사회문제
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• 제21권2호
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• pp.177-203
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• 2015

본 연구는 도박자와 비도박자를 대상으로 비합리적 도박신념과 도박행동의 관련성을 확인하고, 기존 연구들이 직접 다루지 않았던 인지적 오류로서 확률적 사고 오류, 귀인양식 및 귀인편향성이 도박행동에 관련되는지에 대해 알아보았다. 248명의 자료를 수집하여 비(非)도박자, 경(經)도박자, 중(重)도박자로 구분하고, 비합리적 도박신념, 확률추론 오류, 귀인양식 및 귀인편향성을 비교하였다. 비합리적 도박신념은 비도박자<경도박자<중도박자 순으로 높게 나타났는데, 하위요인으로서 자기과신적 추론에서 유의미한 차이를 보였고 기술과대평가적 추론에서는 통계적으로 유의한 차이없이 세 집단이 모두 척도평균(4점) 이상의 높은 신념을 형성하고 있었다. 또한, 비도박자에 비해 경도박자와 중도박자의 확률추론 오류 정도가 높았다. 중도박자들은 비도박자와 경도박자에 비해 일상적 사건에 대해 외부귀인 정도가 높고 내부귀인 정도는 낮으며 실패상황에 대한 내부귀인 편향성이 높은 것으로 드러나, 중도박자 집단과 경도박자, 비도박자 간 구분되는 인지적 오류 특성들이 확인되었다. 도박여부를 예측하는 선행요인들의 상대적 영향력을 검증한 결과 실패에 대한 내부귀인 편향성, 확률추론 오류, 비합리적 도박신념 중 자기과신적 추론, 일상사에 대한 외부귀인 성향 순으로 도박행동 예측력이 높게 나타났다. 본 연구를 통해 도박자와 비도박자의 인지적 오류 및 편향성에 어떤 차이가 있는지 확인함으로써, 도박자 뿐 아니라 도박을 하지 않는 일반인을 대상으로 도박에 관한 지속적인 홍보와 사회교육의 필요성을 제안하였다.

• Journal of Chest Surgery
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• 제39권11호
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• pp.805-809
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• 2006

배경: Transforming growth factor-beta 1 receptor II(TGF-${\beta}1RII$) 단백질의 과발현이 폐기포 조직의 형성에 관여할 수 있다는 연구 결과를 본 연구팀은 발표한 바 있다. 이와 관련하여 폐기포벽에서 발견되는 섬유화에 관계될 것으로 생각되는 Transforming growth factor-beta 1(TGF-${\beta}1$) ligand의 발현의 변화를 보기 위하여 자연기흉 환자에서 폐기포 절제슬로 획득한 폐 기포조직을 면역조직화학적 염색법으로 염색하여 관찰하려 하였다. 대상 및 방법: 36명의 자연기흉의 환자에서 비디오흉강경 폐기포절제술 시 획득된 폐기포조직을 획득하였다. 36명 환자 중 남자가 34명, 여자가 2명이었고 연령은 14세에서 38세였다. 획득된 폐기포조직을 면역조직화학적 염색방법으로 염색하였다. 결과: 36명 중 19예에서 TGF-${\beta}1$ 양성이었고 24예에서는 transforming growth factor-beta 1 receptor II(TGF-${\beta}1RII$)가 양성이었다. 19예의 TGF-${\beta}1$ 양성 예 중 15예에서 TGF-${\beta}1RII$에도 양성으로 관찰되었다. 이 같은 양성 변화는 폐기포조직과 정상 폐 조직과의 경계선에서 가장 강하게 관찰되었다. 결론: TGF-${\beta}1$의 과발현은 TGF-${\beta}1RII$ 발현의 변이 여부와 마찬가지로 폐기포벽의 섬유화를 초래하여 폐기포 형성에 영향을 미치는 것으로 생각되며 확실한 규명을 위하여 분자생물학적 및 기타 추가적인 연구가 더 필요할 것으로 생각된다.

• 대한방사선기술학회지:방사선기술과학
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• 제39권2호
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• pp.135-142
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• 2016

본 연구는 DR system에서 Chest PA 검사 시 일반적으로 적용되는 SID(180 cm)가 실제 심장크기 및 심흉비를 묘사하는데 적합한 거리인지 고찰해보고, 장비가 지닌 기하학적 원인이 영상에 미치는 영향을 알아보고자 한다. 자체 제작한 Chest phantom과 XGEO-GC80, INNOVISION-SH, UD150B-40 장비에 CXDI-40EG detector를 조합한 X선 발생장치를 이용하였다. 실험방법은 SID를 180 cm로 고정 후 OID를 0, 75, 83 mm로 변화시키며 영상을 획득하였다. 영상은 Centricity Radiography RA1000 PACS system에서 측정하였다. 통계프로그램은 SPSS(Version 22.0, SPSS, Chicago, IL, USA)를 사용하였고, p-value는 0.05 이하를 통계적으로 유의한 것으로 평가하였다. OID 0 mm에서 세 장비 모두 팬텀의 실제 CS, BS 보다 약 2.7~3.5 mm 정도 확대되었고, 계산된 확대율과 비교해 보았을 때 1.6~2.8% 확대되었다. OID 75 mm와 OID 83 mm에서는 6~8 mm 범위에서 CS와 BS가 확대되었다. 계산된 값과 비교했을 때 측정된 값은 6.1~7.9% 확대되었다. OID 변화에 따른 CS와 BS는 각 그룹간에 통계적으로 유의한 차이(p<0.05)를 보였으며, 사후분석에서는 OID 0 mm 그룹만 독립적인 그룹으로 나타났고, 75 mm와 83 mm는 동일한 그룹으로 분리되었다. 하지만 OID 변화에 따라서 통계적으로 유의한 차이가 없었으며(p >0.05), 사후 분석에서도 모두 같은 그룹으로 나타났다. DR system에서 Chest PA 검사 시 일반적으로 이용되고 있는 SID에서 검사하는 경우 심장의 크기는 실제 크기보다 6~8 mm크게 나타나며 이는 실제 이론적인 값보다 6.1~7.9% 확대되어 나타났다.

• Restorative Dentistry and Endodontics
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• 제36권6호
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• pp.465-476
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• 2011

최근의 근관치료학 분야에서 외과적 재치료는 수술현미경, 초음파기구, 미세수술기구 등의 도입으로 많은 변화가 있어 왔다. 본 논문에서는 기존의 전통적인 치근단 수술법과 비교하여 미세 치근단 수술의 주요 술식을 알아보고 이미 출간된 논문에 근거하여 미세 치근단 수술의 성공과 실패 그리고 성공과 실패에 영향을 미치는 요소들을 고찰하고자 하였다. 수술현미경은 수술부위를 밝게 확대해서 봄으로써 치근단 부위의 미세한 형태를 조명할 수 있게 되었으며 이는 술식의 성공을 위해서 필수적인 요소가 되었다. 초음파 기구 또한 치근단 역충전을 위한 정확한 와동형성을 가능하게 해 주었다. 따라서 미세 치근단 수술은 기존방식의 문제점이었던 많은 골삭제, 경사진 치근절제, 부정확한 역충전 와동 형성, 치근단 미세구조 관찰의 어려움 등을 극복함으로써 술식이 더욱 정확해지고, 성공가능성이 더 높아졌다고 볼 수 있다. 미세 치근단 수술에 영향을 미치는 요소에는 다양한 요인들이 존재할 수 있으나 전통방식의 치근단 수술보다 술식이 표준화 됨으로써 술식에 의한 영향을 줄일 수 있다. 환자와 치아에 관계되는 요소 중에서는 치주질환의 이환 여부와 치아위치(tooth position)가 예후에 영향을 미치는 것으로 알려져 있으나 이에 대한 연구는 아직까지 그 수가 부족한 상태로 앞으로 검증수준 (evidence level)이 높은 Randomized clinical trial 혹은 전향적 코호트 연구가 많이 이루어져야 할 것이다.

• 대한치과보철학회지
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• 제36권3호
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• pp.468-482
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• 1998

Since the concept of osseointegration was introduced by Branemark of Sweden, dental implants have been used for various dental prosthetic treatments. The survival rate of dental implant is likely to be closely related to the total biomechanical role of each component of implant system. The use of interchangeable component is very attractive for dental practitioners because such an approach would save treatment cost, flexibility of prosthetic treatment options as well as conveniences. Therefore, the use of interchangeable implant system has been increasing without scientific assessment of safety and efficacy of various interchangeable implant system. The purpose of this study, therefore, were to compare the geometric characteristic of four interchangeable dental implant screws and the loosening torque of these screws. Four types of dental implant screws tested in this study were Nobelpharma, 3i, Impla-med, Restore. Four screws each of the test specimens were subjected for scanning electron microscopic examinations under the same condition and a 35x magnified standard SEM picture was objected from each test specimen using JSM-5200 scanning microscope. From each of the SEM pictures, eight parameters. i.e., diameter of screw head. screw length, thread pitch, major diameter. neck diameter, neck length, crest width and root width were determined using a caliper. The measurement for each parameters were then corrected for their magnification factor. The loosening torque were also determined by using a torque gauge. All of the measurements were statistically analyzed by ANOVA test and multiple range test. Statistical significance was set in advance at the probability level of less than 0.05. All analyses were done with SPSS software for the personal computer. The conclusion obtained from this studies were summarized as the following; 1. No statistically significances were noted in the thread pitch. and crest width in the four screws, and in the case of major diameter, the Impla-med screw was significantly smaller than the other three screws (p<0.05). Therefore, four implant bolts could be physically inserted in a abutment nuts. 2. The diameter of screw head was decreased in the order of Restore, 3i, Nobelpharma, Impla-med screws and the length of screws were decreased in the order of 3i, Restore, Nobelpharma and Impla-med. The diameter of neck was decreased in the order of Impla-med, Restore. Nobelpharma, 3i screws. The differences of each of these parameters were statistically significant (p<0.05). The width of root of screws were decreased in the order of Nobelpharma, Impla-med, Restore and 3i. The differences among Nobelpharma and Impla-med. Restore and 3i were statistically significant (p<0.05). 3. When the screws were loosening 1, 3, 4 and 5 times, the loosening torque for Impla-med and 3i screws were significantly higher than that of Nobelpharma or Restore screws (p<0.05). However, when statistically smaller than that of 3i, Restore or Nobelpharma screws(p<0.05).

• 한국작물학회지
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• 제27권4호
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• pp.340-360
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• 1982

Because of the continuing rapid increase in pesticide usage in Taiwan, much attention has been focus on pesticide contamination of food and effect of pesticides on human and environmental health. The Plant Protection Center (PPC) conducts safety evaluation of pesticides usee! in Taiwan. The pesticides are classified into different groups based on their acute toxicities. Pesticides which are classified into extremely toxic group are not allow to used on short term crops or the continuously harvest crops. The acute toxicity of pesticides to the beneficial insects are also studied, special attention has been paid to the two predators of rice brown planthopper. 60% of cultivated land in Taiwan are paddy field; therefore, acute fish toxicity was taken into consideration when a pesticide was applied for registration to be used in the paddy. Fish toxicities were evaluated by the dangerous rating value which is the amount of pesticide residue in the field water over the TLM value. Mutagenicity of pesticides was continuously evaluated by using Arne's microbial testing method. Island wide survey of residual levels of pesticides of known pollutants such as chlorinated hydrocarbon . insecticides, mercurial compounds in soil, water and biological samples were carried out constantly. The potential of a new1y Imported esticides to pollute the environment were studied by using model ecosystem. Ecological magnification (EM) of a chemical was calculated from model ecosystem. A chemical was considered as a pollutant when its EM value over 5000. In order to ensure the levels of pesticides residue of the crop within the safety limit. The 'tolerance' of pesticides on different crop groupings were established base on 1) acceptable daily intake value of individual pesticides, 2) average daily consumption of each crop groupings by Chinese person, 3) Actual residues of pesticides. on different crops obtained from supervised trials. Total about 79 pesticides for which the tolerances have been established on different crop groupings. Because the intensive agricultural system was adopted in Taiwan. The phytotoxicity of pesticides to the non-target crops was therefore become one of the important factor in the safety evaluation of pesticide usage. These will include 1) direct injury, 2) injury caused by pesticide polluted irrigation water, 3) injury caused by the pesticide polluted soil, 4) reduction of growth caused by the effect of pesticide on the soil microorganisms. This paper will reviewed all the aspects mentioned in the previous .paragraphs. Most the works have done in Taiwan by the PPC.y the PPC.

• 한국농공학회지
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• 제39권4호
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• pp.106-113
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• 1997

Dynamic loading of structures often causes excursions of stresses well into the inelastic range, and the influence of the geometric changes on the dynamic response is also significant in many cases. Therefore, both material and geometric nonlinearity effects should be considered in case that a dynamic load acts on the structure. A structure in a nuclear power plant is a structure of importance which puts emphasis on safety. A nuclear container is a pressure vessel subject to internal pressure and this structure is constructed by a reinforced concrete or a pre-stressed concrete. In this study, the material nonlinearity effect on the dynamic response is formulated by the elasto-viscoplastic model highly corresponding to the real behavior of the material. Also, the geometrically nonlinear behavior is taken into account using a total Lagrangian coordinate system, and the equilibrium equation of motion is numerically solved by a central difference scheme. The constitutive relation of concrete is modeled according to a Drucker-Prager yield criterion in compression. The reinforcing bars are modeled by a smeared layer at the location of reinforcements, and the steel layer model under Von Mises yield criteria is adopted to represent an elastic-plastic behavior. To investigate the dynamic response of a nuclear reinforced concrete containment structure, the steel-ratios of 0, 3, 5 and 10 percent, are considered. The results obtained from the analysis of an example were summarized as follows 1. As the steel-ratio increases, the amplitude and the period of the vertical displacements in apex of dome decreased. The Dynamic Magnification Factor(DMF) was some larger than that of the structure without steel. However, the regular trend was not found in the values of DMF. 2. The dynamic response of the vertical displacement and the radial displacement in the dome-wall junction were shown that the period of displacement in initial step decreased with the steel-ratio increases. Especially, the effect of the steel on the dynamic response of radial displacement disapeared almost. The values of DMF were 1.94, 2.5, 2.62 and 2.66, and the values increased with the steel-ratio. 3. The characteristics of the dynamic response of radial displacement in the mid-wall were similar to that of dome-wall junction. The values of DMF were 1.91, 2.11, 2.13 and 2.18, and the values increased with the steel-ratio. 4. The amplitude and the period of the hoop-stresses in the dome, the dome-wall junction, and the mid-wall were shown the decreased trend with the steel-ratio. The values of DMF were some larger than those of the structure without steel. However, the regular trend was not found in the values of DMF.

• 한국전자파학회논문지
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• 제28권1호
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• pp.49-60
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• 2017

본 논문에서는 임의의 정지궤도 위성의 고출력증폭기(120 W급) 후단에 구성되는 X-대역 원통형 도파관 캐비티 필터의 고전력 핸들링 능력을 연구하고, 그 결과를 제시하였다. 필터의 차수는 6차로 정하였고, 공진기 크기를 원형통 캐비티 모드 차트로부터 도출한 후, 필터의 물리적인 기본 형상을 설계하였다. 이차 전자모델(SEM)인 전자수 진화 시뮬레이션 방법과 전압배율인자(VMF) 방법을 이 필터에 적용하여 멀티팩터(multipactor) 마진을 분석하고 비교하였다. 이 결과, VMF 방법이 전자수 진화 시뮬레이션 방법보다 더 낮은 멀티팩터 임계값을 제공하는 것으로 나타났다. VMF 방법으로 얻은 멀티팩터 분석 마진 값을 유럽표준(ECSS)에서 정하는 기준 마진(단일 캐리어의 경우 8 dB)과 비교하여 실제 시험이 필요하다고 판단하였고, 유럽우주기구(ESA) 시설에서 수행된 시험에서 540 W까지 RF 신호를 입력하였을 때 멀티팩터가 발생하지 않음을 확인하였다. 따라서 분석과 시험을 통하여 X-대역 원통형 도파관 캐비티 필터는 정지궤도에서 운용에 필요한 충분한 고전력 취급 능력이 있음을 보였다.