자당 지방산 에스테르 또는 이소말토올리고당 첨가가 저장 쌀밥의 텍스쳐에 미치는 영향

김명환,김병용,김성곤 ( Myung Hwan Kim,Byung Yong Kim,Sung Kon Kim ) 한국산업식품공학회 1997 산업 식품공학 Vol.1 No.2

해상풍력 해저케이블 하역용 유압식 코일링 암 구조설계 및 해석

김명환,김동현,오민우,Kim, Myung-Hwan,Kim, Dong-Hyun,Oh, Min-Woo 한국전산구조공학회 2013 한국전산구조공학회논문집 Vol.26 No.1

본 논문에서는 해저케이블 부두 하역용 장비인 코일링 암(coiling arm)에 대한 국산화 자체개발 내용 중 구조설계 및 해석결과 내용을 제시하였다. 상세 구조설계를 위해 3차원 CAD 프로그램을 이용하여 고 정밀도의 모델링을 수행하였고, 유한요소 기법을 이용하여 전산구조해석을 수행하였다. 코일링 암의 활용 목적에 맞추어 하역대상 케이블을 선박에서 케이블 탱크로 하역시 효과적으로 가이드 할 수 있도록 베어링 및 롤러 부품을 설계하여 메인 암이 회전하고 케이블 가이드가 이동할 수 있도록 하였고, 기존의 외국 모델에서 사용하던 와이어 및 모터 시스템을 이용한 케이블 가이드 작동방식을 유압 시스템을 이용한 작동방식으로 변경하여 원가절감을 달성하면서 사용자가 직관적으로 작동할 수 있도록 설계하였다. 장비 자체의 자중 및 하역 케이블 하중조건에 대한 응력 해석을 수행하였고, 유압시스템의 과작동에 따른 파손 가능성을 고려하였다. 케이블 가이드의 운동 및 설치 지면의 경사도에 따른 전복 안전성 해석을 수행하였으며, 설치장소의 풍하중 효과도 추가로 고려하였다. 본 연구를 통해 기존 수입품 코일링 암의 작동방식 개선과 독자적인 구조설계 및 해석 방법을 확립하였으며, 실제 국내 최초로 자체 개발된 제품의 현장설치 완료 및 하역작업의 효율적이고 정상적인 운영을 완료 및 검증하였다. Structural design and analysis of a coiling arm unloading machine for submarine cable have been originally conducted in this study. Three-dimensional CAD modeling process is practically applied for the structural design in detail. Finite element method(FEM) and multi-body dynamics(MBD) analyses are also used to verify the safety and required motions of the designed coiling arm structure. The effective moving functions of the designed coiling arm with respect to rotational and radial motions are achieved by adopting bearing-roller mechanical parts and hydraulic system. Critical design loading conditions due to its self weight, carrying cables, offshore wind, and hydraulic system over operation conditions are considered for the present structural analyses. In addition, possible inclined ground conditions for the installation of the designed coiling arm are also considered to verify overturn stability. The present hydraulic type coiling arm system is originally designed and developed in this study. The developed coiling arm has been installed at a harbor, successfully tested its operational functions, and finished practical unloading mission of the submarine cable.

생강 삼투압 건조 시 물질이동 특성과 품질에 미치는 효과

김명환,Kim, Myung-Hwan 한국응용생명화학회 1998 Applied Biological Chemistry (Appl Biol Chem) Vol.43 No.4

생강의 삼투압 건조 중 설탕용액의 농도와 온도 및 침지시간에 따른 내부 물질이동을 생강 내부의 수분손실, 설탕흡수, 몰랄농도 및 속도매개 변수로써 조사하였고 갈색화 반응정도를 평가하였으며 데치기와 삼투압건조를 각각 거친 후 열풍건조 시킨 것에 대하여 복원 시 텍스쳐를 비교하였다. 용액의 농도와 온도가 증가함에 따라서 수분손실, 설탕흡수, 몰랄농도 및 속도매개 변수가 증가하였으며, 용액농도와 온도에 관계없이 수분손실, 설탕흡수, 몰랄농도는 초기 3분간 침지과정에서 빠르게 이루어진 후 증가현상이 둔화되었다. $80^{\circ}C$의 60 Brix 설탕용액에서 18분간 침지하였을 때 40.05 g 수분손실/100 g생강으로 초기 수분함량 83.02%(wet basis) 기준으로 약 52%의 수분을 제거하는 효과를 갖는다. 속도매개 변수는 설탕용액의 농도 보다는 온도에 의한 변화가 컸다. 갈색화 정도는 설탕용액의 농도와 온도에 관계없이 15분간 침지시켰을 때 가장 낮은 O.D.값을 나타내었으며, 대조구(O.D.=0.132)와 비교하였을 때 $80^{\circ}C$에서 40 또는 50 Brix의 설탕용액에 15분간 침지시킨 것이 가장 낮은 값(O.D.=0.027)을 보였다. 데치기 공정을 시킨 것과 대조구를 열풍건조 시킨 다음 끓는 물에서 3분간 복원시킨 후의 관통힘은 차이가 나타나지 않았으나 삼투압 건조시킨 생강은 대조구 보다 $22{\sim}34%$ 적게 나타났다. Internal mass transfer during osmotic dehydration of gingers in sugar solution was examined as a function of concentration, temperature and immersion time of those solutions using moisture loss, sugar gain, molality and rate parameter. Influence of osmotic dehydration on browning reaction and texture properties of air dried rehydrated was also evaluated. Increasing the concentration and temperature of sugar solutions increased moisture loss, sugar gain, molality and rate parameter. Water loss and sugar gain were rapid in the first 3 min and then changed gentle slope. Moisture loss during osmotic dehydration using a sugar solution $(60\;Brix,\;80^{\circ}C)$ with 18 min immersion time was 40.05 g moisture/100 g wet ginger which was 52% reduction of initial moisture content in ginger (83.02%, wet basis). The changes of rate parameter were more affected by temperature than by concentration of sugar solution. Minimum browning degree (O.D.=0.027) was carried out by osmotic dehydration in sugar solution $(40\;or\;50\;Brix,\;80^{\circ}C)$ with 15 min immersion time compared to control (O.D.=0.132). Influence of osmotic dehydration on puncture forces of 3 min rehydrated ginger in boiling water were $22{\sim}34%$ of reduction, while blanching treatment had not affected compared to those of control.

첨가물에 따른 저장 쌀밥의 텍스쳐 특성

김명환,이상규,김성곤 ( Myung Hwan Kim,Sang Kyu Lee,Sung Kon Kim ) 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.40 No.5

The effect of sucrose fatty acid ester(SE, 0∼0.5%, w/w) and oligosaccharide(OS, 0∼1.0%, w/w) additions on texture properties, hardness(H), stickiness(-H), stickiness/hardness(-H/H) and elastic recovery (b/a) of cooked rice stored at 20℃ were studied. The H of stored cooked rice decreased with increasing storage time. The addition of SE and OS showed lower H value than control throughout the storage period up to 12hrs and after 8hrs of storage time, respectively. The -H of stored cooked rice increased with increasing storage time. The -H value of SE added cooked rice showed much lower than that of the control in the early stage of the storage and then almost the same value as that of control. The control and SE or OS added cooked rice resulted the value of -H/H between 0.15 and 0.20, which had been found as acceptable textural parameters, after 10hrs of storage at 20℃. The b/a of stored cooked rice decreased with increasing storage time, but was not significantly affected by additives. After 15 days of storage at 4℃, the addition of SE had greater effect on the reduction of hardness of stored cooked rice than that of OS.

도파로공진을 이용한 슬롯도파로 포화흡수체 반사기

김명환,김상인,Kim, Myung-Hwan,Kim, Sang-In 한국광학회 2011 한국광학회지 Vol.22 No.3

본 논문에서는 도파모드공진을 이용한 포화흡수체 반사기를 제안하였다. 포화흡수체로는 탄소나노튜브(CNT)를 사용하였다. 제안된 반사기는 CNT의 두께 변화 없이 modulation depth를 키울 수 있다는 장점이 있다. 제안하는 반사기의 fill factor(F)와 CNT의 두께변화에 따른 modulation depth, 대역폭, 포화되었을 때의 최대 반사율의 특징을 알아보았다. 제안된 반사기는 포화에너지를 줄일 수 있다는 장점이 있고, 100~200nm 얇은 CNT박막에서 50배정도 줄어드는 것을 확인 하였다. We propose a saturable absorber reflector based on guided-mode resonance. A carbon nanotube is used as a saturable absorber. By tuning the fill factor, modulation depth can be increased without a change of height of the CNT. We investigate the reflector properties such as modulation depth, bandwidth and peak reflectance as a function of the height of the CNT and the fill factor. The advantage of the proposed reflector is that it can reduce saturation energy by 50 times compared with CNT thin film of 100~200nm.

고정방법이 골절선상 치아의 치수 및 치주조직에 미치는 영향에 관한 실험적 연구

김명환(Myung Hwan Kim),이상철(Sang Chull Lee) 대한구강악안면외과학회 1992 대한구강악안면외과학회지 Vol.18 No.3

The purpose of this experimental study was to observe the pulpal and periodontal tissue changes of the teeth in the line of fracture, in cases of rigid fixation with miniplate and reduction without fixation of fractured bone fragments. In order to perform this experimental study, 3 adult male dogs weighing about 10kg were selected. Under the general anesthesia with Pentobarbital sodium (Entobar), buccal cortical osteotomy on the left and right mandibular body was carried out with a #700 fissure bur and a disc. Then, fractures were induced with a bone chisel and a mallet in both sites. The fractured fragments in the left mandibular body were fixated with a noncompressive miniplate and screws, but the fractured fragments in the right mandibular body were reduced without fixation. The experimental animals were sacrificed in the 4th, 6th and 8th week after operation, and the mandibles were dissected out to take the tissue specimens. The specimens were fixed with 10% N-formalin solution and decalcified with 5% nitric acid solution. Then, the specimens were sectioned in 4-6μm with a microtome, and observed through light microscopic study after staining with Hematoxylin-Eosin and Masson s trichrome. The results were as follows: 1. Periodontal tissues were degenerated severely in the lapse of time, the root surface was resorbed in the group of non-fixation. 2. Periodontal tissues were healed and matured form 4 weeks after experiment, and repaired gradually in the group of fixation. 3. Pulpal tissues of the tooth involved in the fracture line, were degenerated partly or generally in the group of non-fixation. 4. Pulpal tissues of the tooth involved in the fracture line, were degenerated slightly and had congested blood vessels, but were almost sound in the group of fixation.

당근 삼투압 건조시 물질 이동과 갈색화 반응에 미치는 효과

김명환(Myung-Hwan Kim) 한국식품과학회 1989 한국식품과학회지 Vol.21 No.2

방사선 투과성 담낭결석에 대한 경구 담즙산 제제 ( ursodeoxycholic acid ) 의 용해 효과

김명환(Myung Hwan Kim),유병무(Byeong Moo Yoo),박선미(Seon Mee Park),김석균(Suk Gyun Kim),송일한(Il Han Song),최호순(Ho Soon Choi),이성구(Sung Goo Lee),서동진(Dong Jin Suh),민영일(Young Il Min) 대한소화기학회 1995 대한소화기학회지 Vol.27 No.4

N/A Background/Aims: The gallstone composition among Asians is known to be different from that of Caucasians. Thus, we tested the hypothesis that the dissolution rate of radiolucent gallbladder stones by oral bile acid may be different between Koreans and Caucasians. Methods: Sixty patients with radiolucent gallbladder stones were treated with ursodeoxycholic acid(10mg/kg) for 6 months. Abdominal ultrasonogram was measured monthly for evaluation of complete dissolution. Results: Complete dissolution of gallstones occurred in 7 patients(l2%), especially in the patients with gallstone diameter5mm. However, symptoms of biliary colic and dyspepsia were relieved during ursodeoxycholic acid treatment in 30(75%) out of 40 patients, without relationship to complete dissolution. Conclusion: The complete dissolution rate of radiolucent gallbladder stones by ursodeoxycholic acid is lower than that of Caucasians. This may be related to the mixing of' calcium bilirubinate and cholesterol stones in the radiolucent stones. Calcium bilirubinate stones of the gallbladder origin are not rare in Koreans and such stones commonly show radiolucency by simple abdominal x-ray film. (Korean J Gastroenterol 1995;27:457-462)

등가모델링기법을 이용한 5MW급 부유식 해상용 풍력발전기 구조동역학해석

김명환(Myung-Hwan Kim),김동현(Dong-Hyun Kim),김동환(Dong-Hwan Kim),김봉영(Bong-Yung Kim) 한국소음진동공학회 2011 한국소음진동공학회 학술대회논문집 Vol.2011 No.10

In this study, the computational structural dynamic modeling of floating offshore wind turbine system is presented using efficient equivalent modeling technique. Structural dynamic behaviors of the offshore floating platform with 5MW wind turbine system have been analyzed using computational multi-body dynamics based on the finite element method. The considered platform configuration of the present offshore wind turbine model is the typical spar-buoy type. Equivalent stiffness and damping properties of the floating platform were extracted from the results of the baseline model. Dynamic responses for the floating wind turbine models are presented and compared to investigate its structural dynamic characteristics. It is important shown that the results of the present equivalent modeling technique show good and reasonable agreements with those by the fully coupled analysis considering complex floating body dynamics.

KSLV-Ⅰ 상단부 고전압 부하용 TVC 배터리 개발

김명환(Myung-Hwan Kim),마근수(Keun-Sum Ma),임유철(You-Chol Lim),이재득(Jae-Deuk Lee) 한국항공우주연구원 2008 항공우주기술 Vol.7 No.2

본 논문에서는 TVC 배터리의 설계 개념, 특성과 환경 및 성능 시험 결과에 대해 간략히 보인다. KSLV-Ⅰ 상단에 탑재되는 TVC 배터리는 168개의 소니 18650VT 고전력 리튬이온 셀을 사용하며, 84개의 셀을 직렬로 구성한 후 각 열을 병렬로 2개 연결하여 추력 벡터제어(TVC) 시스템의 미션에 요구되는 전압(공칭 270V)과 전류를 공급한다. TVC 시스템의 부하 특성은 짧은 시간 동안 높은 전류 출력을 요구하는 펄스의 형태를 가진다. 무게를 최소화하며 시스템 요구 전력을 공급하기 위해 18650VT 셀을 적용하였다. 18650VT 셀은 고전력 응용분야를 위해 설계된 모델로 10C 연속 방전 능력을 갖고 있다. This paper gives a brief summary of the TVC battery design description, specifications and test results. The TVC battery for KSLV-Ⅰ upper stage contains 168 Sony 18650VT high power lithium-ion cells. It configured as 2 strings in parallel, with each string containing 84 series connected cells. This allows to meet nominal 270V voltage and capacity requirements specified for the mission of the Thrust Vector Control(TVC) system. The loads profile of the TVC system has short duration, high current pulse. To power such a system with minimal mass, the battery employed 18650VT Cells. This cell is specifically designed for high rate applications and is capable of a 10C continuous discharge.