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.

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.

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.

축산농가에서 목초액을 이용한 암모니아 가스의 제거 특성에 관한 연구

박정호,전기일,정창훈 한국환경과학회 2003 한국환경과학회지 Vol.12 No.12

This study was carried out to obtain the optimal ammonia removal efficiency using pyroligenous liquid for the economical and environment-friendly odor removal at a petty livestock farmhouse. The ammonia removal efficiencies were evaluated due to changing dilution rates(× 10, ×20, ×30, ×50 and ×100 times) and different spray amounts(10㎖ and 20㎖) of pyroligenous liquid. The wet scrubber device was used to remove odor in closed-type livestock farmhouse. According to dilution rate of the pyroligenous liquid, the optimum rate was 20 times and the removal efficiency increased by decreasing dilution rates. In the case of spray amounts with the optimum dilution, the amount was 20 me and the removal efficiency increased by increasing spray amount. Also, the removal efficiency by using wet deodorizing device was 83.0~97.0% with 20 times diluted liquid.

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.

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.

Rapid Consolidation of WC‑ZrSiO4 Hard Materials by Spark Plasma Sintering: Microstructure, Densification, and Mechanical Properties

Jeong‑Han Lee,Ik‑Hyun Oh,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.9

Densely consolidated WC-based hard materials with 5–20 vol% ZrSiO4was fabricated by spark plasma sintering at 1400 ℃ ata constant heating rate of 70 ℃/min−1. To achieve mechanical alloying of WC-ZrSiO4, planetary ball milling was carried outfor 12 h, during which the brittle-brittle components (WC-ZrSiO4) became fragmented and their particles became refined. Itwas observed that certain, specific, non-isothermal sintering kinetics, such as apparent activation energy, sintering exponents,and densification strain, affected the densification behavior. The evolution of phase structure from powder to compact wasfound to be related the lattice distortion and micro-strain in the basal planes of WC. By examining the mechanical propertiesof the samples, it was that the added zircon content leads to enhanced fracture toughness (12.9 MPa m1/2) owing to thepresence of WC-ZrSiO4 in the cemented carbide. In fact, the microcrack propagation of the fracture passed through zirconfrom a transgranular to a ductile component (fcc) where the crack tips could be absorbed.

성인형 당뇨병에서의 심혈관 합병증과 지질대사와의 관계

박헌진,안정기,이종선,김영건 충남대학교 의과대학 지역사회의학연구소 1989 충남의대잡지 Vol.16 No.1

Hypwelipiswmia is commonly observed in the diabetics, especially with cardiovascular complications. We studied lipid profiles and cardiovascular complication in the 191 adult onset DM patients. The results are as follows: 1. The age distribution was from 24 years old to 82 years old. Male patients were 99 persons, famale patients were 92 persons. The mean disease duration was less than 2 years in the 77 patients, more than 5 years in the 79 patients. 2. Upon the classification between sexes, the mean age was 55±1(SEM) years in the male group, 53±1(SEM) years in the female group. The mean disease durtion was 6.4±1(SEM) years in the female group, longer in the male group (P<0.05). The triglyceride level was 210±16(SEM)㎎% in the male group, 214±13(SEM)㎎% in the female group. The fasting blood sugar level was 147±6(SEM)㎎/dl in the male group, 158±8(SEM)㎎/dl n the female group. The cholesterol level was 229±5(SEM)㎎/dl in the male group, 248±5(SEM)㎎/dl in the female group, higher in the female group (P<0.05). 3. The cardiovascurlar complicatioin (Hypertension, Myocardial infarction, Myocardial ischemia, Angina, Gangrene, Proliferative retinopathy) were present in the 60 patients from 191 patients. Hypertension was present in the 48 patients, and the most prevalent. The mean age and carrdiovascular complication were higher in the more than 5 years of mean disease duration group(mean age 57.99±1.14(SEM)㎎ year) than less than 5 years group(mean age 52.12±0.10(SEM)㎎ year) (P<0.001, P<0.01). 4. The mean disease duration (7.40±1.01(SEM) years), mean triglyceride levels(271±1.01(SEM)㎎%), and mean cholestrerol levels( 257±8㎎.dl) in the cardiovascularly complicated group were higher than those of non-complicated group (P<0.01). 5. The triglycerdie level was high in the obese group (230±14SEM㎎%) than non-obese group (184±15SEM㎎%) (P<0.05). The obese patients were more prevalent in the female group than male group significantly. 6. Considering obesity and cardiovascular complications, the triglyceride value was higher in the obese complicated group(300±30SEM㎎%) than obese non-complicated (197±14SEM㎎ %) or non-obese non-complicated (168±13SEM㎎ %) group (P<0.001). The cholesterol level was higher in the obese complicated group (267±10SEM㎎/dl) than obese non-complicated (230±5SEM㎎/dl) or non-obese non-complicated group(229±7SEM㎎/dl) (P<0.05). 7. Classifying upon insulin response pattern, the obese patients were found in the response pattern, low response pattern, flat type pattern(no response pattern) in the decreasing number of order (P<0.01). The cardiovascular complications were found in the low response group, response group, and flat type pattern (no response) in the decreasing number of order ( P<0.05). The combined cases of obesity and cardiovascular complications were found in the low response group, response group and flat type group(no response) pattern in the decreasing number of order (P<0.01). The mean disease duration was longer in the flat type group (no response) (4.48±0.6SEM years) than the response group(2.43±0.90SEM years) (P<0.05). The mean triglyceride value was higher in the response group (267.38±154.75SEM㎎%) than the flat type(no response group) (198.35±154.05SD㎎%) (P<0.05). So, we conclude that in the NIDDM, obesity control(die control, ideal body weight mainterice, and hyperlipidemia control) is essential for better DM control and cardiovascular complication control.

주사

박정훈,김영근 한국의학사 2000 診斷과治療 Vol.20 No.12