정추력을 위한 양측 다분할 여자형 LDM의 고정자 구조 설계

맹인재,백수현,김용,윤신용,이승명 동국대학교 산업기술연구원 2000 산업기술논문집 Vol.11 No.1

본 논문에서는 양측식 가동자석형 LDM을 대상으로, 고정자 권선을 단일 권선으로 성층할 경우 철심의 중앙부분에서 자기포화로 인해 정추력 발생이 어렵다는 단점을 보완하기 위해 고정자 철심을 분할 권선한 다분할 여자형 LDM의 설계방법을 제안한다. 이를 위해 자극과 코일 사이에 작용하는 힘(F)을 수직력(F_y)과 수평력(F_x)으로 나누어 해석하였으며, 영구자석 폭 대 여자권선 폭비를 추력의 왜형 및 리플이 최소화되도록 가변하여 유한요소해석 소프트웨어인 Maxwell-2D를 이용하여 해석하였다. 이러한 결과에 대한 타당성은 양측 다분할 여자형 LDM을 설계 제작함으로써 입증하였다. This paper was designed and analyzed the characteristics of linear DC motor(LDM) that be suitable to long stroke type. But, according to the magnetic saturation in the center core of the excitation coil of the stator, the control of LDM to get the constant thrust force of difficult because of the non-linearity of the inductance and the reluctance by the position of the slider. In this paper, by designing the width of the stator coil, double sided excitation LDM with multi-separated winding which is possible to obtain the constant thrust force is proposed. Using Maxwell 2D, which is the magnetic field analysis package, and proved the validity of design process, also the characteristics of LDM according to the variation of the design parameters of LDM was almost in accord with the experiment result.

링형 초음파모터의 고정자 진동 해석 및 구동회로 개발

박기준,백수현,김용,윤신용,김일남 동국대학교 산업기술연구원 1999 산업기술논문집 Vol.14 No.-

본 논문에서는 링형 초음파 모터의 고정자의 굽힘진동에 대한 일반적인 해석에 대해 기술하였다. 전기-기계 결합효과를 고려하여 일반화 응력과 변형의 개념을 정립하였고, 일반화 압전방정식, 일반화 응력과 변형의 관계, 미분운동방정식에 대해 기술하였다. 또한 고정자의 진동모드 계산과 공진주파수를 계산하기 위해 유한요소법을 적용하였으며, 유한요소법을 이용한 진동해석 프로그램인 ATILA를 사용하여 고정자의 공진주파수와 변위를 계산하였다. 초음파 모터의 구동을 위해 20kHz 이상의 고주파 전원이 필요하기 때문에 2상 병렬 공진형 인버터를 제작하여 구동전압의 주파수 및 크기를 측정하여 고정자 해석과 구동회로 시뮬레이션과 비교하였다. In this paper, the bending vibration analysis of the stator for a ring type ultrasonic motor is described. Considering the electromechanical coupling effect, the concepts of generalized stress and strain are explained in detail using the generalized piezoelectric equations, which is the relationship between generalized stress and strain, the differential motion equation were derived. The vibration modes and resonance frequencies of the stator were calculated using the finite element code ATILA. For driving of ultrasonic motor, a two-phase parallel-resonant inverter was made. The stator analysis results and driving circuit simulation results are compared with measured frequencies and amplitudes.

한국인 직무 스트레스 측정도구의 개발 및 표준화

장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

Caffeine이 지구성 운동 수행능력에 미치는 영향과 억제성 아미노산에 의하여 활성화되는 이온통로의 조절작용

김은경,김영표,천병옥,이계영,김연정,임백빈,조영욱,김창주,김성수 대한스포츠의학회 1999 대한스포츠의학회지 Vol.17 No.1

To investigate the effect and mechanism of caffeine on endurance exercise, two experiments were performed. First, to test caffeine effect on aerobic exercise, 200-300g Sprague-Dawley rats were used and three groups, control group, low caffeine injection group and high caffeine injection group, were divided. Blood smpling by heart puncture were done at rest, after 30 min treadmill exercise, and after maximal exercise. Blood glucose, free fatty acid concentration were detected and following results were obtained. Glucose concentration showed significant difference between groups(p=0.0305) and also significant changes were exhibited between time(p=0.0004). Free fatty acid concentration had no difference between groups. but had significance between times(p=0.00065). Exercise endurance performance time showed significant difference(p=0.02350 in high caffeine injection group compared to control group. In this experiments, endurance exercise capacity was increased by caffeine injection. Therefore, second experiment was performed to investigate the effect of caffeine on ion current induced inhibitory amino acid neurotransmitter. GABA and glycine. Single periaqueductal gray neuron was acutely dissociated and nystatin perforated patch clamp was performed under voltage clamping condition. Caffeine evoked outward current in PAG neuron dose dependent manner. 1mM of caffeine application had no response. but 3mM caffeine evoked about 32.5±8.539pA outward ion current and 10mM caffeine evoked about 215.46±19.4pA outward current. 10^-2mM GABA activated Cl￣current and recorded by inward current. Caffeine inhibited GABA activated Cl￣ current concentration dependent manner. 10^-2mM of caffeine had no effect on 1-^-2mM of GABA response. but 10^-1mM caffeine inhibited GABA activated Cl￣ current about 5.74±2.13%, 1mM caffeine inhibited about 17.25±2.70%, 10mM caffeine inhibited GABA response about 45.31±7.71%. 10^-1mM of glycine activated Cl￣ current and also recorded by inward current. Caffeine inhibited glycine activated Cl￣ current concentration dependent manner. 10^-2mM caffeine decreased glycine activated Cl￣ current about 4.61±1.650%, 10^-1mM caffeine decreased about 6.49±2.24%, 1mM caffeine decreased about 26.82±4.27%, and 10mM caffeine decreased glycine response about 94.47±1.39%. These results suggest that caffeine inhibite inhibitory amino acid, GABA and glycine, this response causes excitation of CNS and this seems to be the basic mechanism of increasing effect to aerobic exercise performance by caffeine.

Age-related Decline of Inducible Nitric Oxide Synthase Gene Expression in Primary Cultured Rat Hepatocytes

Soo-Youn Baek,Jae-Eun Pie,Hong-Pyo Kim,Seung-Duk Ryu,Woon-Gye Chung,Young-Nam Cha,Chang Shin Park 한국분자세포생물학회 2002 Molecules and cells Vol.13 No.3

Hepatocytes exhibit a non-specific immune response by expressing the enzyme inducible nitric oxide (NO) synthase (iNOS, NOS2) through the stimulation of a mixture of cytokines, or a single cytokine such as interleukin- 1β. We examined the age-dependent inducibility of the iNOS gene expression and the capacity of NO production in response to lipopolysaccharide (LPS) or interleukin-1β (IL-1β) in primary cultured rat hepatocytes that were isolated from the livers of rats, 3 (young) and 24 (aging) months of age. NO production (NO2 −), indicating iNOS activity, was much higher in the young rat hepatocytes following stimulation with LPS or IL-1β. Likewise, in the young hepatocytes, Western blot analyses showed much higher protein levels in the iNOS expression; it was also a little higher in mRNA levels that were analyzed by RT-PCR. Furthermore, after stimulation with IL-1β, the levels of transactivation of nuclear factor-κB (NF-κB) that were involved in the induction of the iNOS gene were reduced without a significant difference in the aged cells. Therefore, the decrease of NO formation in the aged hepatocytes was due to the belated and incomplete inducibility of the iNOS protein expression, together with a minor contribution of the reducedtransactivation of NF-κB. These results suggest that the age-related decline of the iNOS gene expression in primary rat hepatocytes may be associated with the increased incidence of many infective diseases with aging.

Design and Antitumor Activity of A Novel Polymeric Prodrug of Platinum (2) Complexes

Youn Soo Sohn,Hyong Gee Baek,Yang Ha Cho,Young A Lee,Ok Sang Jung,Chong Ok Lee,Yun Soo Kim 생화학분자생물학회 1996 제4회 산학연 심포지움 Vol.- No.-

Differential Inhibitory Action of Taurine between Electrically Evoked Response and Low $Mg^{++}-Induced$ Spontaneous Activity in the CA1 Area of the Rat Hippocampal Slices

Baek, Soo-Youn,Yang, Sung-Gu,Lee, Chang-Joong The Korean Society of Pharmacology 1997 The Korean Journal of Physiology & Pharmacology Vol.1 No.5

Although one of the major physiological functions of taurine(2-aminoethanesulfonic acid) is the inhibitory action on the central nervous system(CNS), the mechanism of taurine in controlling the neuronal excitation in the CNS has been in controversy. Electrically evoked pEPSP and spontaneous activity induced by the perfusion of low $Mg^{++}-ACSF$ were recorded in the CA1 pyramidal cell layer of the hippocampal slice. To test the inhibitory effect of taurine on spontaneous responses, taurine was treated for 2 min at various concentrations(1 mM-10 mM). Taurine reduced the spontaneous activity by 22.2% at 1 mM, and 100% at 2 mM in low $Mg^{++}-ACSF$. Evoked response was induced by electrical stimulation of Schaffer collateral-commissural fibers. Taurine reduced the evoked response by 11.68% at 3 mM, and 24.25% at 5 mM. Even 20 mM of taurine reduced the evoked response only by 24 % after 5 min treatment. That is, the inhibitory efficacy was much higher in spontaneous activity than in evoked response. The $GABA_A$ receptor antagonist, 100 uM bicuculline, blocked the inhibitory action of taurine, while $GABA_B$ receptor antagonist, 700 uM phaclofen, did not. Taurine blocked the spontaneous activity in the presence of CNQX, and did not block the electrically evoked responce in the presence of APV. The results suggest that taurine causes hyperpolarization in the cell by binding to $GABA_A$ receptor and preferentially attenuates NMDA receptor-mediated hyperexcitation, leaving synaptic transmission unmodified.

Effects of Age at First Insemination on Reproductive Performance and Parturition Problems of Holstein Heifers

Kwang-soo Baek,Hyun-sang Youn,Jun-soo Kim,Hyun-Joo Lim,Ho-beak Yoon,Eung-gi Kwon,Hyun-suk An,Yeon-sub Jung,Sun-kyu Kim 한국동물생명공학회(구 한국동물번식학회) 2014 한국동물번식학회 한중일 심포지엄 Vol.2014 No.1

인버터 파형 변화에 따른 유도전동기의 손실 특성 고찰

백수현(Soo-Hyun Baek),윤신용(Shin-Yong Youn),김성철(Seong-Cheol Kim),김필수(Pill-Soo Kim) 대한전기학회 1995 대한전기학회 학술대회 논문집 Vol.1995 No.7

미세 스텝 변화에 따른 LPM의 정전류제어

백수현(Soo-Hyun Baek),윤신용(Shin-Yong Youn),임태빈(Tae-Bin Im),김철진(Cherl-Jin Kim),하근수(Keun-Soo Ha) 대한전기학회 1996 대한전기학회 학술대회 논문집 Vol.1996 No.7