Fe-Mn-C계 TWIP강의 재질특성에 미치는 소둔온도와 첨가원소의 영향

정종구,김남규,윤여선,김현호,이오연,Jung, Jong-Ku,Kim, Nam-Kyu,Yeon, Yeo-Sun,Kim, Hyun-Ho,Lee, Oh-Yeon 한국재료학회 2010 한국재료학회지 Vol.20 No.7

Twinning-induced plasticity (TWIP) steels have attracted great attention due to their excellent mechanical properties of high tensile strength (over 800MPa) and high ductility (over 50%), which result from the high strain hardening due to the mechanical twin formation during plastic deformation. The purpose of this study is to investigate the effect of annealing temperature and alloying elements on the mechanical properties of Fe-18Mn-0.6C TWIP steel. In 1.5%Al TWIP steel with 0.123%Ti content, the average recrystallized grain size was reduced to 2.5 ${\mu}m$ by cold rolling and annealing at $800^{\circ}C$ for 5 min, because of the pinning effect of the fine TiC carbides on grain coarsening. The tensile strength was decreased and the ductility was improved with the increase of the annealing temperature. However, a reversion of hardness and yield strength happened between $750^{\circ}C$ and $800^{\circ}C$ due to TiC and $M_3C$ type precipitation. 0.56% Ni added TWIP steel exhibited relatively lower yield strength, because Ni precipitates were not formed during the annealing process. When this specimen was annealed at $800^{\circ}C$ for 5min, the tensile strength and elongation were revealed at 1096MPa and 61.8%, respectively.

임프란트 고정체와 지대주 직경의 차이가 응력분포에 미치는 영향

정종원,이청희,Jung Jong-Won,Lee Cheong-Hee 대한치과보철학회 2004 대한치과보철학회지 Vol.42 No.5

Statement of problem : Stress concentration on the neck bone affects the bone resorption, and finally the implant survival. Purpose: In order to examine the stress distribution on the neck bone and prosthesis abutment for implants, decreasing abutment sizes were used. Material and methods : Axisymmetric models were used to obtain the data required. These models were composed of 4mm implants with 3.4mm and 4mm abutments, 5mm implants with 3.4mm and 5mm abutments and 6mm implants with 3.4mm and 6mm abutments. All abutments were designed to received a 10mm high by 10mm diameter gold crown. Functional element analysis was used to obtain these results using data that consisted of 50 N vertical and 45 degree inclination forces. Results : 1. Changing the diameter of the abutment on the implant affects the effect of the inclination forces more than the effect of the vortical forces. 2. Changing the diameter of the abutment on the implant affect the effect of the inclination forces more than the effect of the vertical forces. 3. Experimentation showed that the larger diameter implants provided a decreased neck bone stress, whereas a larger diameter abutment provided a decrease marginal abutment stress. 4. Experimentation showed that the neck bone and abutment received more stress from inclination forces than vertical forces, Conclusions: By decreasing the size of the abutment on the implant we were able to diminishneck bone stress.

대퇴골두 골괴사증에서 시행한 인공 고관절 전치환술 -최소 10년 이상 추시-

정종원 ( Jong Won Chung ),박상원 ( Sang Won Park ),한승범 ( Seung Beom Han ),박종훈 ( Jong Hoon Park ),김호중 ( Ho Jung Kim ),이원석 ( Won Suck Lee ) 대한고관절학회 2010 Hip and Pelvis Vol.22 No.2

Purpose: The aim of this study was to assess the outcome of cementless total hip arthroplasty (THA) in cases of osteonecrosis of the femoral head. Materials and Methods: We studied long-term outcomes for 54 patients (72 hips). Mean duration of follow-up was 13.5 years. Clinical outcomes were evaluated by the Harris Hip Score. Radiographic evaluation from the preoperative and follow-up periods included assessment of the fixation of the femoral and acetabular components, polyethylene wear, osteolysis, and radiolucent line. Results: The mean Harris Hip Score improved from a preoperative value of 51.9 points to 89.4 at final follow-up. Regarding the femoral components, there was radiographic evidence of stable bony ingrowth in 69 hips, stable fibrous ingrowth in 2 hips and unstable fixation in 1 hip. There was a radiolucent line of less than 1 mm in 7 hips, and femoral osteolysis in 27 hips. Regarding the acetabular components, there was radiographic evidence of stable fixation in 68 hips, unstable fixation in 4 hips, and osteolysis in 39 hips. There was a significant correlation between (i) failure of components and (ii) femoral osteolysis, acetabular osteolysis, polyethylene thickness, linear wear rate per year, or total linear wear. Conclusion: The findings of this study show favorable long term results, both clinical and radiographic, using cementless total hip replacement arthroplasties. However, the revision rates for the Harris-Galante acetabular components were high. Wear of the load? weight? bearing surface continues to limit the long-term success rate of THA, and improved design of the acetabular components should be considered.

진동 모니터링 기반 변압기 상태 진단 기법

정종만(Jong Man Joung),강병권(Byoung-Gwon Kang),허정훈(Jung-Hoon Hur),이주경(Ju kyoung Lee),이춘권(Chun-Kwon Lee) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.10

주상변압기의 상 불균형 및 상태 이상을 3축 진동 센서를 이용하여 추정하고 이를 주파수 특성에 기반하여 각 상태를 분류하였다. 이를 위하여 3차원 공간에 3축 주파수 고조파 특성값들에 대하여 벡터 밀도기반 클러스터링 기법을 사용하였다.

분말활성탄이 투여된 무산소/호기공정과 전기분해공정의 조합에 의한 안료폐수의 총질소와 유기물질 제거 특성

정종식(Jong Sik Jeong),정유상(Yu Sang Jung),이국두(Kuk Doo Lee),이재복(Jae Bok Lee) 大韓環境工學會 2004 대한환경공학회지 Vol.26 No.5

강원도 방태산의 지표성 딱정벌레류(딱정벌레목: 딱정벌레과)의 군집구조 및 분포

정종국 ( Jong Kook Jung ),김승태 ( Seung Tae Kim ),이수연 ( Sue Yeon Lee ),유정선 ( Jeong Seon Yoo ),이준호 ( Joon Ho Lee ) 한국환경생태학회 2011 한국환경생태학회지 Vol.25 No.3

강원도 인제군 소재 방태산 자연휴양림 일대에서 2010년 6월부터 10월까지 채집한 1,041개체의 지표성 딱정벌레류는 7아과 18속 34종으로 동정되었다. 아과별 종 수(species richness)는 길쭉먼지벌레아과 15종(44.1%), 딱정벌레아과 7종(20.6%), 먼지벌레아과 4종(11.8%), 가슴먼지벌레아과 3종(8.8%) 및 기타 아과 5종(14.7%) 등의 순이었다. 우점종은 Synuchs속 일종(260개체, 25.0%), 민줄딱정벌레(218개체, 20.9%) 및 수도길쭉먼지벌레(205개체, 19.7%)이었다. 고유종은 11종 564개체가 채집되었다. Principal component analysis(PCA) 결과, 서식처의 식생 및 주변 환경의 특성에 따라 종 구성 및 발생 밀도에 차이가 있었다. 특히 딱정벌레아과 및 길쭉먼지벌레아과와 같은 산지에 서식하는 지표성 딱정벌레들은 방태산 자연휴양림 내의 활엽수림 및 침엽수림을 선호한 반면, 무늬먼지벌레아과 및 먼지벌레아과 대부분은 초지와 인접한 지점에서만 출현하여 숲과 인접한 초지의 유무 등 서식환경의 차이가 지표성 딱정벌레류 분포에 중요한 요인이었다. 산림에서의 지표성 딱정벌레 군집 및 분포에 관한 분석 결과는 앞으로 환경변화에 따른 장기모니터링 및 산지 보존프로그램을 수립하는데 유용한 자료로 제공될 것이다. Ground beetle fauna of Mt. Bangtaesan in Inje-gun, Gangwon-do was investigated from June to October in 2010. Ground beetles were collected by pitfall trapping. A total of 34 species of 18 genera belonging to 7 families were identified from 1,041 collected ground beetles. Species richness was high in Pterostichinae (15 species, 44.1%), Carabinae (7 species, 20.6%), Harpalinae (4 species, 11.8%), Nebriinae (3 species, 8.8%) and others (5 species, 14.7%). Dominant species were Synuchus spp. (260 individuals, 25.0%), Aulonocarabus semiopacus (218 individuals, 20.9%), and Pterostichus audax (205 individuals, 19.7%) in order. Korean endemic species were collected 564 individuals belonging to 10 species. By principal component analysis (PCA), species distribution and abundance of ground beetles were different depending on habitat characteristics of vegetation, surrounding environment and feeding habitat. Carabinae and Pterostichinae which live in the forest were preferred in hardwoods and coniferous in the Bangtansan Natural Recreation Forest, while Callistinae and Harpalinae were collected in forest adjacent to grasslands. Overall, differences of habitat environments within forest are important factors associated with distribution of ground beetles. This result will provide useful informations with establishment of conservation program and long-term monitoring against environmental change within mountain by using ground beetles.

생태통로 내부 식생구조에 대한 지표성 딱정벌레류(딱정벌레목: 딱정벌레과)의 반응

정종국 ( Jong Kook Jung ),박유정 ( Yu Jeong Park ),이선경 ( Sun Kyung Lee ),이효석 ( Hyo Seok Lee ),박영균 ( Young Gyun Park ),이준호 ( Joon Ho Lee ),최태영 ( Tae Young Choi ),우동걸 ( Dong Gul Woo ) 한국환경생태학회 2016 한국환경생태학회지 Vol.30 No.2

최근 서식처 파편화에 의한 생물다양성 감소를 막고 서식처간 연결성을 증진시키기 위해 건설되는 생태통로의수가 증가하고 있지만, 생태통로 내부의 식재 및 식생 유지·관리에 대한 구체적인 가이드라인과 내부 식생 구조 차이에 따른 생물 이동 영향에 대한 정보는 부족한 실정이다. 따라서 본 연구에서는 지표성 딱정벌레류를 이용하여 동일한 농업-산림 경관에서 육교형 생태통로 상부 식생이 나지 및 초본으로 이루어진 생태통로(나지/초본형)와 관목림이우거진 생태통로(관목형)에 대한 비교 연구를 수행하였다. 이를 위해 2015년 4월 하순부터 9월 초순까지 생태통로 및 인접한 산림을 따라 함정트랩을 설치하여 33종 4,207개체의 지표성 딱정벌레류를 채집하였다. 지표성 딱정벌레류의 우점종과 지점별 개체수 및 종수는 생태통로 내부의 식생이 복잡한 관목형이 나지/초본형에 비해 더 높은 경향이었으며, 종 구성은 나지/초본형 생태통로의 종 구성은 인근 산림 지역 및 관목형 생태통로에 비해 다른 특징을 보였다. 이와유사하게 생태통로 내부의 식생 관리 여부는 토양습도와 교목층 울폐도에 영향을 주었고, pH, 초본층 피도 및 교목층울폐도는 함정트랩이 설치된 위치에 따라서도 유의미한 차이를 보였다. 결론적으로 생태통로 내부의 식생이 복잡해지면 산림에 서식하는 지표성 딱정벌레류의 산림 패치간 이동 역시 증가할 것으로 판단된다. 따라서 생태통로의 생태적기능을 향상시키기 위해서는 통로 가장자리에는 관목 또는 교목을 식재하여 은신처 및 이동통로로 제공하고, 중앙부에는 대형 포유동물이 이동하기 용이한 나지 형태의 통로를 제공하는 형태로 개선될 필요가 있을 것이다. Korea has put in significant efforts to increase the number of wildlife crossings between fragmented habitats to prevent loss of biodiversity and to encourage the habitat connectivity in Korea. However, there is a lack of biological data on the effect of vegetation structure in these wildlife crossings and guidelines for design and management of wildlife crossing structures in Korea. Therefore, we selected ground beetle assemblages as model organisms to compare the effect of vegetation structure in wildlife crossings, i.e. bare ground- and shrub-type corridors, in agro-forested landscapes. For this study, 4,207 ground beetles belonging to 33 species were collected through pitfall trapping along the northern forest.corridor.southern forest transects from late April to early September in 2015. Dominant species, abundance, and species richness of ground beetles were significantly higher in the shrub-type corridors than the bare ground-type corridors. Also, the species composition of bare ground-type corridor was significantly different compared to the other habitats such as shrub-type corridor and forests. Similarly, environmental variables were also influenced by vegetation management regimes or trap locations. Collectively, our study clearly indicates that the movement of forest associated ground beetles between forest patches can increase as the vegetation in wildlife crossings becomes complex. Although further studies are needed to verify this, there are indications that the current wildlife crossings that comply with the guidelines may be unfriendly to the movement of ground dwelling arthropods as well as ground beetles. To enhance the ecological function of wildlife crossings, the guidelines need to be rectified as follows: 1) Shrubs or trees should be planted along the corridor verges to provide refuge or movement paths for small mammals and ground dwelling arthropods, and 2) Open spaces should be provided in the middle of the corridors to be used as a path for the movement of large mammals.

증례 : 조혈모세포이식술 후 보리코나졸로 치료한 중추신경계 아스페르길루스증 1예

정종원 ( Jong Won Chung ),양덕환 ( Deok Hwan Yang ),김상호 ( Sang Ho Kim ),이세련 ( Se Ryeon Lee ),김여경 ( Yeo Kyeoung Kim ),이제중 ( Je Jung Lee ),김형준 ( Hyeoung Joon Kim ) 대한내과학회 2006 대한내과학회지 Vol.71 No.1S

신생아 경련의 원인과 신경 발달의 예후 인자 분석

정종식(Jong Sik Jung,),이지훈(Ji Hoon Lee),전가원(Ga Won Jeon),신종범(Jong Beom Sin),이보련(Bo lyun Lee) 대한소아신경학회 2014 대한소아신경학회지 Vol.22 No.3

Purpose: The purpose of this study was to investigate the clinical features of neonatal seizures and to identify prognostic factors of neurodevelopmental outcome in term infants who experienced clinical seizures. Methods: A retrospective analysis was performed on 153full term and preterm infants with seizures from January 2008 to December 2013. Binary logistic regression analysis was applied to assess risk factors associated with neurological adverse outcomes using variables that were found to be significant on univariate analysis. Results: During the study period, 102 (66.7%) term and 51 (33.3%) preterminfants were enrolled. The main cause of neonatal seizures was hypoxic ischemic encephalopathy (24.5%) in term infants and intracranial hemorrhage (74.5%) in preterm infants. The most common type of seizure was focal clonic seizure. Generalized tonic seizure was more commonly observed in preterm than in term infants. 39 out of 56 term infants with at least 12 months of neurologic followup showed normal outcomes while only one preterm infant showed normal development.Prognostic factors related to adverse neurodevelopmental outcomes in term infants were perinatal history of fetal distress, etiology of hypoxic ischemic encephalopathy, severity of EEG(Electroencephalogram) abnormality, evidence of hypoxic ischemic encephalopathy on brain magnetic resonance imaging, and the need for multiple antiepileptic drugs for seizure control. Conclusion: Preterm infants showed poorer neurodevelopmental outcomes compared to term infants. The etiology of seizures, treatment response, neuroimaging and electroencephalographic findings were important in predicting the developmental outcome in term infants with seizures.

배전 가공전선 상태별 열화상 진단특성 분석

정종만(Jong-Man Joung),허정훈(Jung-Hoon Hur),이주경(Ju-Kyoung Lee),김상현(Sang-Hyun Kim),강병권(Byoung-Gwon Kang) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.7