Effect of Impact Velocity on Interface Characteristics of HT‑9 Steel Joints Fabricated by Magnetic Pulse Welding

Jun‑Woo Song,Jin‑Ju Park,Gyoung‑Ja Lee,Min‑Ku Lee,Kyu‑Hyun Park,Soon‑Jik Hong,Jung Gu Lee 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.3

The weldability window in magnetic pulse welding (MPW) is proposed for the end-closure joining of HT-9 steel tubularworkpieces. Based on both theoretical and experimental investigations, the impact velocity of the flyer tube at the momentof collision had a dominant effect on the bonding characteristics of the resultant joints and the optimal impact velocity wasestimated to be in the range of 265–290 m/s in this alloy system. Under the optimal process conditions, no leak was detectedduring helium leak testing. Moreover, the integrity of the joint interface was preserved until the tube section ruptured duringinternal pressure burst testing. For HT-9 steel, the ductile δ-ferrite phase produced by the localized interfacial melting duringMPW acted as an effective obstacle to crack propagation, thereby enhancing the fracture resistance of the joint interface. Allof the results demonstrated the high integrity and durability of the HT-9 steel tube assembly fabricated by the MPW process.

병식 평가 척도-한국판(SUMD-K)의 신뢰도와 타당도 검증

송지영,김기태,이서경,김용희,노준호,김종우,장환일,반건호,강원섭 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.4

Objectives : This study was conducted to evaluate the reliability and the validity of the Korean version of the Scale to Assessment Unawareness of Mental Disorder (SUMD-K). Methods : The subjects were 55 schizophrenic patients between ages of 26 and 58 who were recruited from the psychiatric unit of the university hospital and the out-patient clinic. The SUMD-K and insight scale of PANSS were applied to the patients. Results : The range of inter-rater (Spearman's rho) of the general items of SUMD-K were .97-.98 on the current illness and .58-.98 on the past illness. The correlation coefficient between the sum and the general items of the SUMD-K showed high scores. The concurrent validity between SUMD-K and insight item of PANSS was high (scores between .59-.96). However,the reliability and the validity of the attribution items of symptoms showed low scores compared to the current symptoms. Conclusion : The SUMD-K was confirmed in its reliability and validity. It can be a useful clinician-rating scale for evaluating insight in schizophrenic patients as well as patients with other neuropsychiatric conditions.

슬래그계 카올린모르타르의 에트링가이트 생성과 물성에 미치는 무수석고의 영향

송태웅,김준우 경남대학교 신소재연구소 1999 論文集 Vol.11 No.-

고로슬래그를 주성분으로 하는 카올린모르타르용 결합재에 에트링가이트계 자극제로서 무수석고를 사용할 때 그 첨가량이 에트링가이트의 생성과 모르타르의 초기 물성에 미치는 영향을 관찰하였다. 무수석고의 첨가는 에트링가이트와 생성과 모르타르의 초기강도 발현에 매우 효과적이었으나 적정량 이상 첨가하면 에트링가이트의 성장이 미약하고 미반응 CaSO4가 잔존하여 다시 강도가 하락하였다. The effects of ettringite-forming anhydrite on the early properties of the slag-based kaolin mortars were studied. The addition of anhydrite, within certain amounts, was very effective for the formation of ettringite. hydraulic reactivity and the early strength of the mortars. The strength of the mortar, however, was decreased by the excessive anhydrite which is remaining without reaction and suppressing the growth of the ettringite crystals.

흰쥐에서 음경발기 평가의 척도로서 음경해면체내압측정술 확립

송윤섭,김용준,이광우,김준모,문기혁,박영호,민영기,유형균,김형건 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Purpose: Because studies about the control of penile erection at the entral nervous system was dependent on the animal experiments, establishment of measuring penile erection is important to evaluate the effects changes at the central nervous system on the penile erection. Intracavernous pressure measurement in rats has been introduced as a suitable index for the evaluation of penile erection but this method is invasive and technically difficult. So, we established the intracavernous pressure measurement in rats as the experimental index for penile erection. Materials and Methods: 42 male adult Sprague-Dawley rats (250-300gm) were divided to saline or papaverine treated group. Rats were placed on a heating table to maintain their body temparature and anesthetized with 50mg/kg of pentobarbital sodium by intraperitoneal injection. A cannula was inserted to the left carotid artery to measure systemic blood pressure. Saline (0.05, 0.1ml), papaverine(0.05, 0.1, 0.25, 0.5, 1.0, 2.0mg) were injected intracavernously via 26 guage needle filled with saline or papaverine which connected to pressure transducer and polygraph was inserted into the corpus cavernosum on one side to inject the drug and to measure intracavernous presure. Results: Properly executed insertion and intracavernous administration produced a instantaneous but transient rise in intracavernous pressure that substantially stabilized and maintained at 5.4±0.4mmHg. Intracavernous pressure and duration of penile blood flow following intracavernous injection of papaverine are increased comared to those of saline. Conclusions: Monitoring intracavernous pressure in rats represents a suitable index for the evaluation of penile erection in small laboratory animals.

기저질환이 없는 사람에서 발생한 Campylobacter fetus에 의한 재발성 심내막염 1예

전재범,정진원,김성혜,송문희,오형철,안성기,최상호,김남중,김양수,우준희,류지소 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

C. fetus 심내막염은 드물게 발생하는 질환으로 주로 면역능이 저하된 환자에서 발병하고 대동맥판을 침범하는 경우가 많으며 적절한 치료가 되지 않을 경우 치사율이 높다. 저자들은 기저질환이 없던 69세 남자에서 C. fetus 심내막염을 경험하였기에 문헌고찰과 함께 보고하는 바이다. 환자는 발열로 내원하여 시행한 혈액배양 검사상 C. fetus가 동정되었고 경식도 초음파 검사상 삼첨판에 증식증이 발견되어 심내막염 진단하에 ceftriaxone에 이어 meropenem으로 총 4주간 항생제를 투여받고 호전되었다가 한달 후 다시 재발하였고 판막부전 소견 진행하여 삼첨판 치환술을 시행받고 전신상태 호전되어 퇴원하였다. Campylobacter fetus is a rare cause of endocarditis. To date, only about 30 cases of C. fetus endocarditis have been reported mainly in the elderly with chronic underlying illnesses. Most cases showed tendency to involve aortic valve. This report describes a case of native tricuspid valve infective endocarditis in a 69-year-old man without any underlying disease. Despite adequate antibiotic therapy for 4-weeks, endocarditis recurred and leading to surgical valve replacement.

영상피드백에 의한 로봇 지능제어

김준홍,Nguyen Huu Cong,이우송,한성현 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

The equipment of industrial robot in manufacturing and assembly lines has rapidly increased. In order to achieve high productivity and flexibility, it becomes very important to develop the visual feedback control system with Off-Line Programming System(OLPS). We can save much efforts and time in adjusting robots to newly defined workcells by using OLPS. A proposed visual calibration scheme is based on position-based visual feedback. The calibration program firstly generates predicted images of objects in an assumed end-effector position. The process to generate predicted images consists of projection to screen-coordinates, visible range test, and construction of simple silhouette figures. Then, camera images acquired are compared with predicted ones for updating position and orientation data. Computation of error is very simple because the scheme is based on perspective projection, which can be also expanded to experimental results. Computation time can be extremely reduced because the proposed method does not require the precise calculation of tree-dimensional object data and image Jacobian.

고지방식이와 에스트로겐이 콜레스테롤 항상성에 관련된 유전자의 발현에 미치는 영향

김준우,송지현,김영미 한국지질학회 2000 韓國脂質學會誌 Vol.10 No.2

쇠고기육중의 방사선 유래 휘발성물질의 분석

차용준,박지영,김훈,박승영,조우진,송양순,유영재 창원대학교 생활과학연구소 2000 생활과학연구 Vol.4 No.-

This study was conducted to identify irradiation-derived volatile components, having positive-correlation with irradiation doses, which may play roles as maker materials for detecting post-irradiation in pork meat. The volatile components of irradiated(0, 1, 3, 5 and 10 kGy doses) pork(Belly) meat was analyzed by liquid liquid continuous extraction(LLCE)/GC/MSD methods. By the results of linear regression analysis between irradiation doses and volatile component amounts in fresh pork, 3 compounds including γ-octalactone(r=0.82), 1-octen-3-ol(r=0.90) and butanoic acid(r=0.81) had high correlations with irradiation doses.

TCP 트래픽의 성능 측정

최우철,송화선,정영준 강원대학교 정보통신연구소 2003 정보통신논문지 Vol.7 No.-

The performance evaluation of Internet traffics has been performed by factors such as RTT and packet loss. This individual evaluation method has some difficulties in determining service quality due to interoperations between those factors. This paper presents a hybrid performance evaluation formula for TCP traffics, which uses both RTT and packet loss. The formula has been defined by an interpretation model, which is derived from a TCP throughtput rate in congestion environment and a packet retransmission mechanism. The proposed formula has been applied to a data set collected from the KREN performance measure, and then has been shown to easily determine TCP performance variations. Thus, the proposed scheme can be used for a SLA monitoring system.

제주도 토양의 감귤나무(Citrus unshiu Marc.)에서 ^137Cs의 전이

강태우,박원표,송성준,유장걸 제주대학교 방사능이용연구소 2001 연구보고 Vol.15 No.-

본 연구는 제주도 토양 감귤나무에서 ^137Cs의 전이를 조사하기 위하여 유기물 함량이 서로 다른 제주도내 6개 지역의 감귤원에서 채취한 감귤과 토양시료를 감마분광계로 ^137Cs 농도를 측정하였고, 또한 토양화학 특성과의 관계를 조사하였다. 토양 중 ^137Cs 농도는 10.2∼40.0 Bq/kg dry 범위로, 유기물 함량이 높을수록 높은 경향을 보였다. 식물체 중 ^137Cs 농도는 가식부위의 경우는 검출하한치 이하 ∼91.8 mBq/kg·fresh, 잎은 검출하한치 이하 ∼235 mBq/kg·fresh의 범위로 가식부위, 껍질 그리고 잎 순으로 높았다. 토양에서 식물체로의 ^137Cs 전이계수는 잎, 껍질 그리고 가식부위에서 각각 2.15×10^-3∼1.25×10^-2, 7.28×10^-4∼8.13×10^-3 그리고 3.79×10^-4∼3.08×10^-3 범위로 가식부위, 껍질 그리고 잎 순으로 높았다. 토양 pH에 따른 ^137Cs의 전이계수는 서로 상관성이 없었으나, 치환성 K와 토양 유기물 함량이 높을수록 전이계수는 낮아지는 경향이 있었다. 우리 나라 국민 1인당 20 kg의 감귤을 섭취한다고 가정했을 때 이상의 결과로부터 산출된 흡수선량인 0.0048 μSv은 연간 예탁유효 선량 당량 값인 2.48 mSv에 비하여 거의 무시할 수 있는 수준이라고 생각된다. To investigate transfer of ^137Cs in the mandarin trees of Jeju Island, the fruits and leaves as well as the soil samples around each tree were collected from 6 mandarin orchards with different organic matter content. ^137Cs concentration was measured by HPGe γ-ray spectrometry, the relationship between the transfer values and the soil chemical properties was investigated. ^137Cs concentration in soil was in the range of 10.2~40.0 Bq/kg·dry and increased with increasing organic matter content. ^137Cs concentrations in each part of plant were in the range of MDA(minimum detectable activity)~46.8 mBq/kg·fresh(fruit), MDA~91.8 mBq/kg·fresh(peel) and MDA~235 mBq/kg·fresh(leaf), respectively. The distribution of ^137Cs in trees was showed as the following order; fruit<peel<leaf. Transfer factors of ^137Cs from soil to tree were in the range of 2.68×10^-3~1.02×10^-2, 9.07×10^-4~4.03×10^-3 and 4.73×10^-4 ~ 2.04×10^-3 for leaf, peel and fruit, respectively. The transfer factors were as the following order; fruit<peel<leaf. The transfer factors of ^137Cs from soil to tree were not affected by soil pH, but decreased at the high concentration of exchangeable K and organic matter.