차동 기어의 진동 저감을 위한 동력 전달계 진동 해석

최은오,김희송,안병민,홍동표 한국공작기계학회 1997 한국생산제조학회지 Vol.6 No.3

Eigenvalue analysis of vibration mode and an analysis by frequency response among the methods of predicting gear noise are related with transmitting sound of vibration. In this study we intended to reduce the vibration noise of differential gear by reducing torque fluctuation of drive pinion shaft which causes vibration noise of differential gear in rear wheel drive vehicles. For this we developed multi-degree of freedom analysis model in which mass moment of inertia and torsional spring combined and we examined the influence of torsional vibration of driveline elements by performing forced vibration analysis of engine excitation torque. We studied the methods for reducing torsional vibration of driveline according to the design factor of propeller shaft and examined the effect reducing vibration in differential gear by flexible coupling.

기어쌍의 래틀진동에 대한 영향도 평가 및 기어 진동 저감을 위한 대책 제시

안병민,최은오,홍동표 한국공작기계학회 1998 한국생산제조학회지 Vol.7 No.3

In recent year, as the demand about low vibration and noise vehicle is increased constantly, automobile companies try to a lot of things to achieve this demand. Gear rattle vibration become an emergency problem to be cured at idling. There are two kinds method to reduce idle gear rattle vibration. One is optimization of clutch damper design parameters(stiffness, hysteresis torque, preload, length of 1st stage), the other is system parameters modification(inertia, drag torque, backlash, etc.). But these methods are impossible to estimate influence rate of each gearpair on the idle gear rattle vibration. In this study, 14 degrees of freedom nonlinear model is developed to analyze influence rate of each gearpair on the idle gear rattle vibration and the counterplan to reduce the gear noise is suggested through the shift system modification.

가우시안 혼합 출력 HMM을 위한 변분 베이지안 방법

오장민(Jangmin O0),장병탁(Byoung-Tak Zhang) 한국정보과학회 2005 한국정보과학회 학술발표논문집 Vol.32 No.1

은닉 마코프 모델은 이산 동역학을 표현할 수 있는 확률 모형이다. 우도 함수 최적화를 수행하는 전통적인 Baum-Welch 학습 알고리즘은 국소해로 수렴하기 쉬우며, 우도함수의 특성상 복잡한 모델을 선호하는 바이어스가 존재한다. 베이지안 프레임워크에서는 파라미터를 랜덤 변수로 보고 이에 대한 사후 확률 분포를 추정하여 이 문제를 해결할 수 있다. 본 논문에서는 베이지안 추정을 위한 결정론적 근사화 기법인 변분 베이지안 방법을 이용, 출력 노드에 가우시안 혼합 노드를 지니는 일반화된 HMM의 추론 방법을 유도한다. 인공 데이터에 대한 실험을 통해, 본 방법이 효과적인 HMM 학습을 수행할 수 있음을 보인다.

전주산업단지 및 주변지역 VOCs 및 악취물질 모니터링

김용문,박비오,고영삼,심재정,송병식,양고수 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

Important main odorous compounds and VOCs(volatile organic compounds) possibly emitted from the Jeon-Ju Industrial Sites were identified and measured in amount through making air sampling over Jeon-Ju Industrial Sites and analyzing them with the sate of the art analytical instrument. Sampling sites were chosen 8 points by considering the industrial characteristics for the 1,2 Industrial Sites and 2 points for the 3 Industrial. Site Sampling times were two times, the first one was March. 2002 - April. 2002, and the second was May. 2002 - July. 2002. Canister sampling units and polyester bags were used to collect 6 liters air samples during 1hour or 3minutes for VOCs and polyester bags were used to sample 10 - 50 liters of air for 3 minutes depending on analytic characteristics of odor compounds. The important main VOCs were measured as acetone, ethyl benzene, n-hexane, m,p-xylene, toluene, M.E.K.(methyl ethyl ketone), isopropanol, ethyl acetate, o-xylene, n-butyl acetate, ethanol, benzene as in order of average concentration for the Industrial Sites. The main odorous compounds were COS, H2S, CS2, MM(methyl mercaptan), form aldehyde, acetaldehyde for the 1,2 Industrial Sites and COS, H2S, form aldehyde, acetaldehyde were measured as main species for the 3 Industrial Site. NH3 was measured as below the detection limit of the instrument. The concentrations of sulfide compounds for the 1,2 Industrial Sites were relatively higher than ones for the 3 Industrial Site. Among aldehydes, form aldehyde, acetaldehyde were detected very highly as 0.1- 1ppm over all the Industrial Sites.

신규 플루오로퀴놀론계 DWP20367 의 흰쥐 및 개에서의 체내동태와 조직분포

심점순(Jeom Soon Shim),유영효(Young Hyo Yu),남권호(Kweon Ho Nam),박명환(Myung Hwan Park),공재양(Jae Yang Kong),조재열(Jae Youl Cho),한승희(Seung Hee Han),김병오(Byoung O Kim),정대영(Dae Young Jeong),이재욱(Jae Wook Lee),손호정(Ho Jun 한국응용약물학회 1997 Biomolecules & Therapeutics(구 응용약물학회지) Vol.5 No.3

The pharmacokinetics and tissue distribution of DWP20367 (1-cyclopropyl-6-fluoro-8-chloro-7-(2,7-diazabicyclo[3,3,0]oct-4-ene-7-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid), a novel fluoroquinolone, were examined in rats and beagle dogs after a single intravenous and oral administration. Analysis of DWP20367 in plasma, tissue, and urine was determined by both HPLC and microbiological assay (bioassay). The plasma concentration-time curves of the drug in rats and beagle dogs were biexponentially declined. The terminal halflife (t_(½β)) of the drug in rats was about 60.1 ±7.3 min (i.v.) and 61.3 ±12.4 min (p.o.) in bioassay, and 86.3 ±19.8 min (i.v.) and 50.9±14.9 min (p.o.) in HPLC. In beagle dogs, half-life of the drug determined by bioassay was about 121.8±6.2 min (i.v.) and 111.0±7.6 min (p.o.). The volume of distribution at steady-state (Vd_(ss)) was 243.8±74.1 ml/kg (bioassay) and 339.2±84.3 ml/kg (HPLC) in rats, and 1587.5±536.9 ml/kg (bioassay) in beagle dogs. The total body clearance (Cl₁,) of DWP20367 was 3.4±0.4 ml/min/kg (bioassay) and 2.4±0.4 ml/min/kg (HPLC) in rats, and 12.3±1.0 ml/min/kg (bioassay) in beagle dogs, respectively. The extent of bioavailability after oral administration was 89.1 %(bioassay) and 79.9% (HPLC) in rats, and 78.7% (bioassay) in beagle dogs. Urinary recovery (24-h) assayed by bioassay was 0.7% (p.o.) and 1.2% (i.v.) in rats, and 0.8% (p.o.) and 1.0% (i.v.) in beagle dogs. In rats, 24-h fecal recovery determined by bioassay was 11.2% (p.o.) and 0.1% (i.v.). Rat and human serum protein binding ratios at 2 ㎍/ml were about 90∼91%. This drug determined by bioassay was also distributed by the order of liver, kidney, lung, heart, spleen and muscle 30 min after oral administration.

The Association between Stress Level in Daily Life and Age at Natural Menopause in Korean Women: Outcomes of the Korean National Health and Nutrition Examination Survey in 2010-2012

Byoung-O Choi,이연지,Ji-Ho Choi,Se-Wook Cho,Hyun-Jung Im,Jee-Eun An 대한가정의학회 2015 Korean Journal of Family Medicine Vol.36 No.6

Background: Although several risk factors associated with reduced age at natural menopause (ANM) have been investigated, the results are inconsistent. Excessive stress, which leads to elevation of stress hormones, can also negatively affect reproductive ability, including by accelerating menopause. However, a direct association between stress level and ANM has not yet been demonstrated. Therefore, the object of this study was to investigate the association between stress level and ANM in Korean women. Methods: Study participants were Korean women between 40 and 70 years old who were in natural menopause during the 5th Korean National Health and Nutrition Examination Survey (n=3,176). The level of stress in daily life was estimated based on data from the mental health topics of the survey. We used the t-test and one-way analysis of variance to analyze the correlation between stress level and ANM. Regression (β) coefficients calculated by multiple regression analysis were used to estimate various factors affecting ANM. Results: Women who experienced a high level of stress in daily life had a lower mean ANM than women with a low stress level (50.17±3.7 and 50.58±3.5 years, respectively), with a statistically significant correlation (P<0.05). This correlation was still observed after adjusting for age, body mass index, menstrual regularity, and personal income (P<0.05 for variables). Conclusion: In Korean women between 40 and 70 years of age who are in natural menopause, there is a statistically significant correlation between stress level and ANM. In particular, women who experience a high level of stress in daily life have reduced ANM.

고체에어로졸 자동소화장치 특성

최병오(Choi, Byoung-O),홍창수(Hong, Chang-Su),권성원(Kwon, Seong-Won),박선규(Park, Sun-Gyu) 한국화재소방학회 2008 한국화재소방학회 학술대회 논문집 Vol.2008 No.추계

기존의 범용적인 분말 소화기 또는 가스계 소화장치와는 달리, 특정 성분의 고체 물질이 연소할 때 발생하는 알칼리 금속염이 함유된 에어로졸 형태의 고농도 소화성분으로 화재를 진압하는 자동소화 장치를 개발하였다. 이 장치는 화재발생 시 자동으로 작동되며, 이때 방출되는 에어로졸은 입자 크기가 <TEX>$1.0{\mu}g$</TEX> 이하로 매우 작아 우수한 소화성능을 나타내며, 또한 지구 환경에 영향을 미치는 유해성분을 포함하지 않는 환경 친화적인 차세대 자동소화장치이다. We developed fixed aerosol auto fire-extinguishing systems which are different from fire suppression systems like powder extinguisher or halon extinguishing system, etc. Fixed aerosol auto fire-extinguishing substances which are including solid alkali salts generated by combustion of solid composition. It represents high fire suppression ability due to particle friendly auto fire-extinguishing systems for the reason of excluding toxic substances in it's composition.

C7- 이환체 구조를 갖는 새로운 플루오로퀴놀론계 항생물질의 흰쥐 체내동태와 조직분포

조재열(Jae Youl Cho),한승희(Seung Hee Han),김병오(Byoung O Kim),남권호(Kweon Ho Nam),손호정(Ho Jung Son),이재욱(Jae Wook Lee),유영효(Young Hyo Yu),박명환(Myung Hwan Park) 한국응용약물학회 1997 Biomolecules & Therapeutics(구 응용약물학회지) Vol.5 No.3

The pharmacokinetics of DWP20364 (1-cyclopropyl-5-amino-6,8-difluoro-7-(2,7-diazabicyclo[3,3,0] oct-4-ene-7-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid), a novel fluoroquinolone containing C7-bicyclic structure, were compared with those of ciprofloxacin (CPFX) after single intravenous (i.v.) and oral (p.o.) administration to rats using microbiological assay (bioassay). After i.v. administration to rats, the plasma concentrations of the two drugs declined biexponentially. The terminal half-lives (t_(½β)) of DWP20364 were 110±13.2 min and 117±3.09 min after i.v. and p.o. administration, respectively, and they were significantly higher than those of CPFX (45.5±9.52 min and 48.3±12.1 min, respectively). Similar results were also obtained from plasma concentrations and area under the plasma concentration-time curves. The total body clearance of DWP20364, 7.82±0.37 ml/min/kg was significantly slower than that of CPFX, 27.3±11.1 ml/ min/kg. Above data suggested that the antimicrobial activity of DWP20364 could be lnger than that of CPFX. The urinary recovery after i.v. and p.o. administration of DWP20364 was signifcantly lower than those of CPFX suggesting that the effect of DWP20364 on urinary tract infection could be lower than that of CPFX. The serum protein binding values of DWP20364 at 2 ㎍/ml were apparently 91.5∼93.1% in rats and human. DWP20364 was distributed by the order of liver, lung, kidney, spleen, heart, muscle and brain collected at 30 min after orally administered.

Switching of Slow Magnetic Relaxation Dynamics in Mononuclear Dysprosium(III) Compounds with Charge Density

Lim, Kwang Soo,Baldoví,, José,J.,Lee, Woo Ram,Song, Jeong Hwa,Yoon, Sung Won,Suh, Byoung Jin,Coronado, Eugenio,Gaita-Ariñ,o, Alejandro,Hong, Chang Seop American Chemical Society 2016 Inorganic Chemistry Vol.55 No.11

<P>The symmetry around a Dy ion is recognized to be a crucial parameter dictating magnetization relaxation dynamics. We prepared two similar square-antiprismatic complexes, [Dy(L-OMe)(2)(H2O)(2)](PF6) (1) and Dy(L-OMe)(2)(NO3) (2), where L-OMe = [CpCo{P(O)(O(CH3))(2)}(3)], including either two neutral water molecules (1) or an anionic nitrate ligand (2). We demonstrated that in this case relaxation dynamics is dramatically affected by the introduction of a charged ligand, stabilizing the easy axis of magnetization along the nitrate direction. We also showed that the application of either a direct-current field or chemical dilution effectively stops quantum tunneling in the ground state of 2, thereby increasing the relaxation time by over 3 orders of magnitude at 3.5 K.</P>

식용식물자원으로부터 활성물질의 탐색-IX. 흰씀바귀(Ixeris dentata forma albiflora)뿌리에서 Sesquiterpene Lactone 화합물의 분리 및 구조 동정; ACAT, DGAT 및 FPTase 효소 활성의 저해

방면호,장태오,송명종,김동현,권병목,김영국,이현선,정인식,김대근,김성훈,박미현,백남인,Bang, Myun-Ho,Jang, Tae-O,Song, Myoung-Chong,Kim, Dong-Hyun,Kwon, Byoung-Mog,Kim, Young-Kuk,Lee, Hyun-Sun,Chung, In-Sik,Kim, Dae-Keun,Kim, Sung-Hoon,Par 한국응용생명화학회 2004 Applied Biological Chemistry (Appl Biol Chem) Vol.47 No.2

식용식물자원으로부터 활성소재를 찾기 위하여 흰씀바귀 뿌리를 80% MeOH로 추출하고, 얻어진 추출물을 EtOAc, n-BuOH및 $H_2O$로 용매 분획하였다. EtOAc와 n-BuOH 분획에 대하여 column chromatography를 반복하여 4종의 화합물을 분리하였다. 각각에 대하여 2D-NMR을 포함한 스펙트럼 데이터의 해석과 문헌 자료를 조사하여 zaluzanin C (1), $9{\alpha}-hydroxyguaian-4(l5),10(14),11(13)-triene-6,12-olide$ (2), $3{\beta}-O-{\beta}-D-glucopyranosyl-8{\beta}-hydroxyguaian-4(15),\;10(14 )-diene-6,12-olide$ (3), $3-O-{\beta}- D-glucopyranosyl-8{\beta}hydroxyguaian-10(14)-ene-6,12-olide$ (4)로 구조를 결정하였다. 이들 화합물에 대하여 ACAT(Acyl-CoA: cholesterol acyltransferase), DGAT (diacylglycerol acyltransferase) 및 FPTase(farnesyl-protein transferase)의 활성에 미치는 억제효과를 측정하였다. Compound 1과 Compound 2는 DGAT에 대한 활성억제효과에 있어서 $IC_{50}$ 값이 각각 0.13 mM, 0.10 mM로 나타났고, FPTase에 대하여는 각각 0.15 mM, 0.18 mM로 나타났으며, ACAT에 대하여는 약한 억제 활성을 나타냈다. 따라서 흰씀바귀는 항암 및 항고혈압의 소재 개발에 있어서 유용한 자원으로 활용될 수 있을 것이다. The root of lxeris dentata forma albiflora was extracted with 80% aqueous MeOH and solvent fractionated with EtOAc, n-BuOH and water, successively. From the EtOAc and n-BuOH fractions, four sesquiterpene compounds were isolated through the repeated silica gel and ODS column chromatographies. The chemical structures were determined as zaluzanin C (1), $9{\alpha}-hydroxyguaian-4(l5),10(14),11(13)-triene-6,12-olide$ (2), $3{\beta}-O-{\beta}-D-glucopyranosyl-8{\alpha}-hydroxyguaian-4(15),10(14 )-diene-6,12-olide$ (3), and $3{\beta}-O-{\beta}- D-glucopyranosyl-8{\beta}hydroxyguaian-10(14)-ene-6,12-olide$ (4) through the interpretation of several spectral data including 2D-NMR. Some showed the inhibitory effects on DGAT (Diacylglycerol acyltransferase), ($IC_{50}$ values of 1, 2: 0.13, 0.10 mM), the catalyzing enzymes of the intracellular esterification of diacylglycerol and FPTase (Famesyl-protein transferase), ($IC_{50}$ values of 1, 2: 0.15, 0.18 mM), the farnesylation enzyme for Ras protein charge of cancer promotion.