Fault Diagnosis of Roll Shape Under the Speed Variation in Hot Rolling Mill

Chang Woo Lee,Hyun Kyoo Kang,Kee Hyun Shin 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.9

The metal processing system usually consists of various components such like motors, work rolls, backup rolls, idle rolls, sensors, etc. Even a simple fault in a single component in the system may cause a serious damage on the final product. It is therefore necessary to diagnose the faults of the components to detect and prevent system failure. Especially, the defects in a work roll are critical to the quality of strip. It is especially difficult to detect faults of a roll by using the existing frequency analysis method if the speed of the roll is changing. In this study, a new diagnosis method for roll eccentricity under the roll speed changes was developed. The new method was induced from analyzing the rolling mechanism by using rolling force models, radius -speed relationship, and measured rolling force, etc. Simulation results by using the field data show that the proposed method is very useful.

안구적출에 따른 위둔덕의 Calbindin D-28k과 c-fos의 변화에 관한 연구

김명,김기훈,김주영,하현철,안명수,김장민,조향훈,정명섭,장인엽 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.2

Changes of Calbindin D-28k- and c-fos-immunoreactivities in the superior collicuclus after Eye Enucleation. Objective and methods: Calcium-binding proteins (CBPs) play an important role in the protection, differentiation and reorganization of the central nervous system. The effects of neonatal retinal deafferentation on a CBPs, calbindin D-28k were examined immunohistochemically in the superficial layer of the rat superior colliculus. Also early gene familly c-fos was examined to evaluate the neuronal characteristics in the superior colliculus after monocular enucleation. Results: On the experimental side of superior colliculus, the number of calbindin D-28k-immunoreactive (IR) cells was reduced (77.4% compared to control), but not fibers. Appearance of c-fos-like immunoreactivity was represented much more in the ipsilateral superior colliculus than contralateral side within 24h after eye enucleation. Conclusion: These results suggest that the changes of retinotectal projection may alter the expressional pattern of calbindin D-28k and c-fos expression.

Fault Diagnosis of Roll Shape Under the Speed Variation in Hot Rolling Mill

Lee, Chang-Woo,Kang, Hyun-Kyoo,Shin, Kee-Hyun The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.9

The metal processing system usually consists of various components such like motors, work rolls, backup rolls, idle rolls, sensors, etc. Even a simple fault in a single component in the system may cause a serious damage on the final product. It is therefore necessary to diagnose the faults of the components to detect and prevent system failure. Especially, the defects in a work roll are critical to the quality of strip. It is especially difficult to detect faults of a roll by using the existing frequency analysis method if the speed of the roll is changing. In this study, a new diagnosis method for roll eccentricity under the roll speed changes was developed. The new method was induced from analyzing the rolling mechanism by using rolling force models, radius-speed relationship, and measured rolling force, etc. Simulation results by using the field data show that the proposed method is very useful.

강원도지역에서 발생한 발진열과 쯔쯔가무시병

민창홍,장우현,강재승,조수익,최문기,조민기,윤창순,김윤원 대한감염학회 1988 감염 Vol.20 No.2

In Korea, there has been an increasing concern on rickettsiosis as one of most prevailing acute febrile illness, since murine typhus and scrub typhus had not been reported for 2 decades until 1986 and thereafter a few studies were reported on these diseases. A microimmunofluorescence test was used to study antibodies to R. typhi and R. tsutsugamushi in urban and rural inhabitants students, and patiants suspected of leptospirosis or rickettsiosis from 1986 to 1987 in Kangwon-do Korea. 43% of inhabitatnts and 17% of students reacted to R. typhi. Only one inhabitant among inhabitants and students reacted to R. tsutsugamushi. Among 169 patients, 43(25%) reacted to R. typhi, 38(22%) to R. tsutsugamushi and 25(15%) to Leptospira interrogans. Sexual rate(male; female) in murine typhus was 1.7:1, that in scrub typhus was 1:2.2 and that in leptospirosis was 1.5;1. The age ditribution of patients with murine typhus was generally even over 20 years old. But 71% of patients with scrub typhus were over 40 years old. Scrub typhus was most prevailing in female over 40 years old. Murine typhus was relatively more prevailing in Choonchun city than rural area as compared with scrub typhus and leptospirosis. Most of scrub typhus occurred in rural area. Most of each disease occurred between September and November (murine typhus; 93%, scrub typhus; 95%, leptospirosis; 84%) with a peak in October. Scrub typhus considerably occurred not only October(58%) but also November(28%). All patients with scrub typhus were immediately diagnosed by antibody when they visited hospital. 53% of patients with murine typhus were diagnosed when they visited hospital within 7 days after onset of illness, and others were done by second sera obtained 8 days after. The patients in whom IgM was seronegative but antibodies of other class were seropsitive by 20 days after onset of illness, were 14% in murine typhus and 26% in scrub typhus. At least those patients were considered to be infected second. Murine typhus and scrub typhus were suggested to be endemic diseases in Kangwon-do as antibodies of inhabitants and characteristics of patients' sera were considered. By serologic finding of patients with scrub typhus in Kangwon-do, Gilliam was 59'% of etiologic strain of scrub typhus, Karp was 41q% and Kato was none. Most scrub typhus occurred in person to be related to agriculture, but murine typhus was not related to job and occurred more in small city than rural area. Rash was scarcely detected in murine typhus and scrub typhus, and eschar was in 50% of scrub typhus only. Serum transaminase elevated in many patients with scrub typhus and murine typhus. Leukocytosis and abnormal finding in chest X-ray were showed in some patients with scrub typhus but were scarcely in murine typhus.

묵논의 식생천이에 관한 연구

이창석,박현숙,유영한,홍선기 서울여자대학교 자연과학연구소 1998 자연과학연구논문집 Vol.10 No.-

폐경년도가 다른 묵논에서 식생요인과 환경요인의 변화를 분석하여 천이계열 및 천이의 추진 기작을 밝혔다. 조사지소는 경작 중인 논, 폐경 후 3년(초기 묵논), 7년(중기 묵논) 및 10년째의 묵논(후기 묵논) 및 묵논에 인접한 계곡림(극상림)의 5단계로 구분하였다. 경작 중인 논, 초기 묵논, 중기 묵논, 후기 묵논 및 계곡림에서 각 조사지소의 우점종으로 판단한 천이계열은 뚝새풀군락→사마귀풀군락→갯버들군락→오리나무군락의 순서로 나타났다. 천이단계별 우점종의 분포와 그것의 생활령을 분석하여 파악된 천이의 추진기작은 내성모델을 따르는 것으로 밝혀졌다. 천이단계에 따른 다양성지수의 변화에서 종품부도와 종다양성지수는 초기에 증가하고 중기에 감소하였다가 그 이후 다시 증가하는 경향을 보였으나 균등성지수는 큰 변화가 없었다. 직경급분포도에서 중기 묵논의 갯버들개체군은 정규분포형을, 후기 묵논의 것은 역 J자형을 보여 전자는 그들이 과거적 어느 한 시기에 동시적으로 출현하였음을 반영하고, 후자의 것은 그들이 현재 경쟁상태에 있음을 반영하였다. 후기 묵논에 성립된 오리나 무개체군의 직경급분포도는 역 J자형을 보여 그들이 침입단계에 있음을 반영하였고, 계곡립의 것은 정규분포형을 보여 그들이 안정상태에 있음을 반영하였다. 이러한 식생요인에 대한 분석 결과, 현재 논으로 이용되고 있는 지역의 잠재자연식생은 오리나무군락이 될 것으로 판단되었다. 천이의 진행에 따른 토양환경요인의 변화에서 수분한량은 초기 묵논에서 현저히 증가되었고, 중기 이후의 묵논에서 감소하였다. pH는 큰 변화를 나타때지 않았고, 유기물, N, P, K, Ca 및 Mg함량은 천이의 진행에 따라 증가하는 경향을 보였다. To clarify the vegetational sere and driving mechanism of succession, vegetation and soil environmental factors were investigated in the old paddy field with different in the lapsed years after abandonment, Study sites were divided into 5 stages of the paddy field under cultivation, the old paddy fields of the initial, middle and late stages, and the climax forest of the mountainous valley near to the abandoned paddy fields. Sere estimated from dominant species of above mentioned study sites was shown in the order of Alpecurus aequalis var. amurensis community, Aneilema keisak community, Juncus effusus var. decipiens community, Salix gracilityla community, and Alnus japonica communt. y. Driving mechanism of succession inferred from the distribution of dominant species in each successional stage and their life form was based on the tolerance model. Species richness and diversity indices steadily increased since the middle stage but evenness index did not show any distinct change. In frequency distribution diagrams of diameter classes, Salix gracilistyla population of the middle and the late stages showed normal and reverse J-shaped distribution patterns, respectively. Result of the former reflects that individuals composing of that poulation were invaded simultaneously in a given time of the past and that the latter suggests that they are in state of intraspecific competition. Distribution diagram of Alnus japonica population in the late stage showed reverse J-shaped distribution pattern reflects that those individulas are in the stages of invasion and that of the valley forest showed normal distribution pattern suggests that they are in stable stage. From the results of analyses on those vegetation data, it was interpreted that potential natural vegetation of the present paddy field might be Alnus japonica community. In changes of soil environmental factors with the progression of succession, soil moisture content rapidly increased in the initial stage and then decreased since the middle stage. Organic matter, N. P. K, Ca and Mg contents tended to increase with the succession stage but pH did not show any distinct change.

Usefulness of Skin Explants for Histologic Analysis after Fractional Photothermolysis

( Gyeong Hun Park ),( Sung Eun Chang ),( Seunghyun Bang ),( Kwang Hee Won ),( Chong Hyun Won ),( Mi Woo Lee ),( Jee Ho Choi ),( Kee Chan Moon ) 대한피부과학회 2015 Annals of Dermatology Vol.27 No.3

Background: Fractional laser resurfacing treatment has been extensively investigated and is widely used. However, the mechanism underlying its effects is poorly understood because of the ethical and cosmetic problems of obtaining skin biopsies required to study the changes after laser treatment. Objective: To evaluate the usefulness of human skin explants for the investigation of fractional photothermolysis. Methods: Full-thickness discarded skin was treated in 4 ways: no treatment (control), fractional carbon dioxide laser, fractional Er:YAG laser, and fractional 1,550-nm erbium- doped fiber laser. Both treated and non-treated skin samples were cultured ex vivo at the air-medium interface for 7 days. Frozen tissue was sectioned and stained with hematoxylin & eosin for histologic examination and nitro blue tetrazolium chloride for viability testing. Results: Skin explants cultured for up to 3 days exhibited histologic changes similar to those observed in in vivo studies, including microscopic treatment zones surrounded by a thermal coagulation zone, re-epithelialization, and formation of microscopic epidermal necrotic debris. However, the explant structure lost its original form within 7 days of culture. The viability of skin explants was maintained for 3 days of culture but was also lost within 7 days. Conclusion: The skin explant model may be a useful tool for investigating the immediate or early changes following fractional photothermolysis, but further improvements are required to evaluate the long-term and dermal changes. (Ann Dermatol 27(3) 283∼290, 2015)

Al-Cu-Mn 합금의 내열특성과 조직변화

章昌範,趙顯麒 경북대학교 산업기술연구소 1987 産業技術硏究誌 Vol.15 No.-

Experiments were carried out to improve the heat-resistance characteristic of Al-Cu-Mn alloy with ageing condition and casting condition. The results obtained were as follows : The alloys were rapidly solidified from the melt at cooling rates between 10^2 and 10^3K/sec using water cooling mold. Specimens which produced by rapid solidification method appeared better heat-resistance characteristic than commonly used mold casting method. By addition Mn element to Al-Cu binary alloys, age hardening was delayed and ageing hardenability was decreased because T phase exist as dispersed phase at solid solution treatment. T' phase revealed better heat-resistance at temperature than θ' phase by TEM observation.

재원기간중 사망한 급성 심근경색증 환자의 임상적 특징

현대우,김기식,신이철,박소영,배장호,한창엽,김윤년,김권배 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.9

Propylthiouracil 투여에 의한 갑상선 기능저하 흰쥐 조직에서 알코올 탈수소효소 활성의 변화

백상현,김동선,이창범,박용수,안유헌,김태화,기춘석,강주섭 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.2

Background: Thyroid hormone has been known to affect hepatic alcohol dehydrogenase (ADH) activity. Although the liver is the principal site of ethanol metabolism, stomach is also responsible in part for ethanol oxidation. The effects of thyroid hormone on ADH activity in gastric mucosa and other tissues of rats had not been previously examined. Method: The effects of thyroid hormone on liver, stomach, lung, and kidney ADH activities (nM of NADH/min/mg of cytosolic protein) have been investigated in male Sprague Dawley rats treated with propylthiouracil (50 mg/kg) for 14 days. Results: Whereas hepatic ADH activities were not changed by treatment with PTU(42.9(8.6 vs 45.2 (10.1), gastric ADH activities in PTU-treated rats increased by 258.8% of control rat (6.3 ( 0.6 vs 2.2 ( 1.2, p〈0.001). In the activities of other tissues, PTU treatment decreased lung ADH activity by 59.7% of control, and increased kidney ADH activities by 247.1% of control rats. Conclusion: These data suggest that hypothyroidism causes an increase of gastric alcohol metabolism, and that the increase of gastric ADH activity can partly restore the first pass metabolism of ethanol in hypothyroid rats.

Magnetron sputtering법으로 제조된 Al-1%Cu/Tungsten Nitride 다층 박막

이기선,서수정,김장현,김남철 공주대학교 자원재활용신소재지역협력센터 2000 2차년도 센터 사업 성과집 Vol.2000 No.1

표면 탄성파 디바이스의 전극재료로 사용되는 Al-1%Cu(4000Å)/tungsten nitride 박막을 magnetron sputtering법으로 제조하고 전기저항을 평가한 결과 비정질상의 tungsten nitride 박막을 제조할 수 있었고, 비정질 형성을 위해서 질소비 (R = N2/(Ar+N2))가 10∼40% 정도 필요하였다. Tungsten nitride 박막의 잔류응력은 비정질이 형성되면서 급격히 감소되었다. 이러한 비정질 박막위에 Al-1%Cu합금막이 형성되었다. 다층막은 453K에서 4시간 동안 열처리함으로써 3.6μΩ-cm의 저항를 나타냈는데, 이는 박막내 결정립 성장과 결정 결함의 감소에 기인하였다. As a power durable-electrode in SAW filter. Al-1%Cu/tungsten nitride multi-layer thin film was fabricated by magnetron sputtering process. Tungsten nitride films had the amorphours phase at the nitrogen ratio, R, ranging from 10~40%. The amorphization could be controlled by nitrogen ratio. R = N2/(N2+Ar) as a sputtering process parameter. Residual stress in tungsten nitride abruptly decreased with the formation of amorphous phase. Al-1%Cu thin film was deposited on the amorphous tungsten nitride. After the multi-layed thin film was annealed for 4 hours at 453K, the resistivity decreased as 3.6 μΩ-cm, which was due to grain growth and reduced crystal defects.