방사선사진의 인덱스-순서 분석을 통한 치아경조직의 탈염화 검출

박동현,박영호,김경숙,박정훈,이기자,최삼진,최용석,황의환,박헌국 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.2

Purpose : The purpose of this study was to develop the radiographic technique for detecting the demineralization which is known as indication of dental caries. Materials and Methods : This technique was based on the comparing of multiple radiographs which was irradiated by multiple X-ray spectra. For the meaningful comparing, the multiple radiographs were reconstructed to the dosimetrically consistent images using a standard material. The difference of resulting images of same target with multiple spectra represents the difference of response of material as regards the spectra. Results : We have found about 10% of demineralization of dental hard tissues particularly in the proximal region through the analyzing of differences. Conclusion : Most intriguing thing in this investigation was that the method to analyze difference shows us to an anatomic structure of dental hard tissues even if absolute values of optical density were excluded during the procedures.

개에서 이중 결찰법을 통한 동맥관 개존증의 완치 예

윤헌영,정순욱,박희명,박철,정만복,김준영,한현정,황민,노병국,박상혁,장하영,박정윤 한국임상수의학회 2004 한국임상수의학회지 Vol.21 No.1

A ten months old, female Yorkshire terrier weighing 2.88 kg referred to veterinary teaching hospital of college of veterinary medicine, Konkuk University because of syncope, cough and dyspnea. First hematological and serum chemical test revealed thrombocytopenia, mild anemia, and increase of concentration of ALP (195 U/L). On 57 days later, second hematological and serum chemical test revealed polycythemia, increase of concentration of ALP (211 U/L), and Tchol (387 mg/dl). Right atrium enlargement, main pulmonary artery bulge and cardiomegaly (VHS = 11.5) were observed in radiographic findings. Ultrasonographic images showed both right and left ventricular dilation and turbulent flow between the descending aorta and the main pulmonary artery in color Doppler imaging. ECG showed left ventricular enlargement, SA block, and electrical alternant. Thoracotomy was performed through left fourth intercostal incision under isoflurane anesthesia. Patent ductus arteriosus was double ligated with 1-0 silk. Cough and dyspnea disappeared on 5 days after operation. Turbulent flow was not found in color doppler imaging of ultrasonography on 10 days after operation. Ten months later after the operation, syncope could not exist any more.

受益者負擔制度에 관한 比較法的 硏究 : 美國의 開發負擔制度를 중심으로 Focusing on the Exaction System in United States

朴貞勳 한국공법학회 2003 公法硏究 Vol.31 No.5

Korea has had a few supplementary systems directly or indirectly focusing on the development share by taxes or the law of development profit redemption, and many problems in a view of supplying public facilities reasonably and effectively. In this study, I introduced the development share system, the center of the beneficiary share system of the United States, which is establishing a very refined system against this matter, and attempted a comparative examination of law to review the Korean law relatively by comparative method. The development share system was divided into four: dedication of land, in-lieu fee, impact fee and linkage, and in the case law the analysis was tried in the classification points of the development share system and taxes by the personality of law. Especially, for the standard suggested as the difference between the development share and taking centered on the Supreme Court of the United States, the argument over the current development share and the nexus of the development permission was introduced and explained. This case law of the United States would be able to contribute to a deeper argument over the development share like a variety of dedication of land in the Supreme Court in Korea.

經濟的 誘因制道 導入擴大를 위한 環境法上 環境政策手段의 比較硏究

박정훈 한국환경법학회 2003 環境法 硏究 Vol.25 No.1

The purpose of this study try to analysis command & control instrument and economic instrument, using 5 evaluation s standards of environmental instrument, environmental effectiveness, economic efficiency, equity, administrative feasibility and cost, and acceptability. And this study suggests that economic instrument is more effective than command & control instrument in solution of environmental problems. When the introduction of new economic instrument, it must be precding of fully investigation with environmental ethics sides, political sides, international competitiveness, rent-seeking activities, ets and sufficient preparation.

Influence of Phase Composition in TiAlSiN Hard Coatings on the Evolution of Structure and Mechanical Properties

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

The aim of this study is to investigate the structural evolution and mechanical properties of TiAlSiN coatings when processedby the arc ion plating method. To form a hard coating, Ti, Al, and Si powders were mechanically alloyed by planetary ballmilling; the powders were then densely compacted during a rapid sintering process into a ternary system coating, i.e. TiAlSi. The evolution of the structural phase from a powder to a compact material is dominated considerably by phase states suchas a supersaturated solid solution or intermetallic compounds. In the case of coating layers, the factors that determine thestructural evolution are associated with the phase stability of the nano-crystalline structure that in turn is associated withthe Ti/Al composition ratio. Motivated by this, we performed experiments to investigate the distribution of microstructures;the material’s binding energy, quantitative properties, transformation of crystal structure, and distribution of amorphous/crystalline were all recorded. In particular, the relationship between the physical and chemical properties during the coatingprocess is considered to be the dominant factor controlling the orientation and morphology of that zone (1, T, and 2). TheTiAlSiN coating layer was found to have hardness above 45 GPa and an adhesion above 100 N. In other words, understandingthe evolution and structure of TiAlSin helped us to produce a material with excellent properties that can be used as a hardcoating. Specifically, these properties were induced by a grain refinement of the nano-crystalline structure that correspondsto an increase in the silicon nitride contents.

인공 치아우식 발생 모델에서 디지털 방사선 공제술을 이용한 인접면 치아우식증의 진단

박정훈,최용석,황의환,이기자,최삼진,박영호,김경숙,진현석,홍경원,오범석,박헌국 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.1

Purpose : The purpose of the experiment was to evaluating the diagnostic ability of dental caries detection using digital subtraction in the artificial caries activity model. Materials and Methods : Digital radiographies of five teeth with 8 proximal surfaces were obtained by CCD sensor (Kodak RVG 6100 using a size #2). The digital radiographic images and subtraction images from artificial proximal caries were examined and interpreted. In this study, we proposed novel caries detection method which could diagnose the dental proximal caries from single digital radiographic image. Results : In artificial caries activity model, the range of lesional depth was 572-1,374 μm and the range of lesional area was 36.95-138.52mm². The lesional depth and the area were significantly increased with demineralization time (p<0.001). Furthermore, the proximal caries detection using digital subtraction radiography showed high detection rate compared to the proximal caries examination using simple digital radiograph. Conclusion : The results demonstrated that the digital subtraction radiography from single radiographic image of artificial caries was highly efficient in the detection of dental caries compared to the data from simple digital radiograph.

스포츠 센터 조직구성원의 리더쉽, 의사소통, 직무만족간의 관계 연구

박정훈,김경남 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.2

The purpose of this research is to find the relationship, leader-employees communication, job satisfaction of sports center employees. To attain the research objective, this study reviewed the previous literatures and derived the research model variable. Consideration and initiating structure were used as the leadership dimension. The subject in this study were 263 employees, who were selected by random sampling form 6 sports centers in Kyonggi Province at Suwon, Pundang. The collected data were handled by reliability analysis, t-test, one-way ANOVA. correlation analysis and regressoin analysis. The finding of this study were as follows: First, official communication, unofficial communication, and job satisfaction are positively related with both dimensions of leadership-consideration and initiating structure. Second, free of official and unofficial communications, and ioh satisfaction are different according to leadership type. These results showed a mere clerk's significant effected by leadership style. So sports center administrator need to more human care about a mere clerk. Third, the relationships between leader-employees official communication and employees job satisfaction in sports centers are different according to leadership type. Especially official and unofficial communications were effected job satisfaction. so role of communication were very important things. If employees were not offer constant information, customers were negatives effected not only sports leaders and sports centers but also repurchasing faith. Fourth, official communication between a sport center leader and employees in sports center is positively associated with unofficial communication for all leadership types. The employees need to awareness of steady to learn exercise knowledge, teaching skills, if not members are diffidence not only sports leaders but also sports center's disagree role of positive recognised. Also the free of unofficial communications are able to satisfied their work too.

Effect of Mechanical Alloying on the Microstructural Evolution of Al60Cr30Si10 Alloys Processed by Spark Plasma Sintering

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

In this study, Al, Cr and Si fine powders were alloyed by planetary ball milling to investigate their microstructural evolution,following their mechanical alloying behavior. The formation of Al(Cr) supersaturated solid solution by the Cr grainsembedded in Al-matrix, which contributed substitutional structure is discussed in relation to their structural evolution inaccordance with the distortion of a crystal lattice. The compacts of Al–Cr–Si alloys were prepared by rapid sintering withina short time by dense consolidation above the density of 99.9% as the formation of intermetallics, except in the case of thedistribution of single-phases induced by the Al-melting. The formation behavior of intermetallics was dominated by dependenceon the structures of the milled-powder and subsequent sintering temperature. To estimate the consolidated behaviorsof compacts, various approaches derived from TEM and XRD analysis were taken to obtain microstructural evidences ofthe inter-diffusion, following the presence of thermally stable intermetallics.

EPC 주강품의 Carbon Pick-up 현상

박익민,김대석,김정훈 한국주조공학회 2005 한국주조공학회지 Vol.25 No.1

금호강 유역 산림의 경관생태적 패턴분석

박경훈,정성관,이현택,오정학,김경태 한국지리정보학회 2004 한국지리정보학회지 Vol.7 No.3

산림의 단편화와 같은 인위적 교란은 유역생태계의 지속성에 영향을 미치기 때문에, 본 연구는 각종 개발사업에 따른 산림의 단편화를 사전에 예방하기 위해서 경관지수와 GIS를 이용하여 금호강 유역에 분포하는 산림구조를 정략화하였다. 소유역 단위의 경관지수값은 인자분석에 의해 전체분산을 또% 정도 설명하는 3개의 공통인자를 단순화하였다. 산림단편화 정도는 소유역별 인자점수를 토대로 계산하였고, 이는 도시지역 면적률(r=0.827, p<0.01, R2=0.685), 고도(r=-0.637, p<0.01)그리고 경사도(r=-0.593, p<0.01)와 상호관련성이 있는 것으로 나타났다. 이상과 같이 본 연구는 금호강 유역관리를 위한 산림경관의 건전성 및 구조적 패턴을 평가하기 위한 방법론과 경관지수값을 제시하였다. 향후에는 경관패턴 및 그 변화가 유역환경의 건전성에 미치는 영향을 규명하기 위한연구가 필요할 것이다. An artificial disturbance like fragmentation in watershed forest has impacted a sustainability of watershed ecosystem, therefore this research quantified the landscape structure in the Geumho river watershed using landscape indices and GIS. Landscape indices were calculated from the forest distributed maps for 24 subwatersheds. Three common factors, which explained about 85% of the variation in the original data, were extracted by a factor analysis. The fragmentation gradient in forest landscape, which was calculated from the factor scores, was correlated with proportion of urban land (rte. 827, p<0.01, R²=0.685). elevation (r=-0.637, p<0. 01) and slope gradient (r=-0.593, p<0. 01) . The result of the study presented that the methodology and the values of landscape indices to assess the structural patterns of forest landscape for the Geumho river watershed management. Future research will be directed towards the detection of impacts of landscape patterns and their changes on the integrity of watershed environments.