견인용 동기전동기의 시동 및 운전특성 해석에 관한 연구

황정원,조용길,송호신,박한규,우정인 東亞大學校 1994 東亞論叢 Vol.31 No.1

It needs a large capacity of equipments to test the starting performance of middle and large synchronous motors in a factory. This paper propose a new method which is the combination of single phase AC applied test and usual routine test with a small synchronous test machine and testing equipments. We can obtain the results from these proposed tests as follows ; (1) The starting performance and stabilized operation at variable speed is predicted from this results. (2) The armature winding leakage reactance is resulted from the no-load saturation curve, the short-circuit charactristic curve and the armature-reaction magnetomotive force converted to the field current. (3) This test must be performed twice, one for short-circuiting the field winding, the other for joining a resistance between the field terminals, as a result the unknown constants in equivalent circuits are identified. (4) Inverter-fed three phase voltage with variable frequency is applied to armature terminals, as a result, We show the actual armature leakage reactance and reaction of the induced harmonic voltages from rotor.

나노크리스탈 약물 전달 기술

황우신,황성주,박정숙,조정원 충남대학교 약학대학 의약품개발연구소 2012 藥學論文集 Vol.27 No.-

Nanotechnology affects on various aspects including medicine and pharmaceutics. This nanocrystal technology which transforms to nano-sized material is able to develop the innovational formulation strategy for poorly water-soluble drugs due to the change of physicochemical properties of drug. Scale-up methods using pearl milling or high pressure homogenizer was described and commercialized products based on nanotechnology were introduced in this manuscript.

Searching condition of image-based analysis for tomato of seedling period using High-throughput phenotyping system

Hwang-weon Jeong,Jihee Park,Young-Joo Seol 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.10

Effects of Isometric Exercise on Muscle Activity and Body Balance Ability in Asymmetrical Walkers

Young Ae KWON(Young Ae KWON),Mun Young HEO(Mun Young HEO),Jeong Weon KIM(Jeong Weon KIM),Hwang Woon MOON(Hwang Woon MOON) 한국스포츠과학회 2023 스포츠과학연구(JSAS) Vol.7 No.1

Purpose: This study was to investigate the effects of isometric exercise on muscle activity and body balance ability in asymmetrical walkers. Research design, data, and methodology: Twenty gait asymmetry people were divided to unilateral exercise group (UG, n=10) and bilateral exercise group (BG, n=10). UG were performed unilateral exercise for 60 minutes, three times a week, and 16 weeks, and BG were performed one side and then the other side alternately for 60 minutes, three times a week, and 16 weeks. Muscle activity and body balance ability were measured before, after 4 and 16 weeks isometric exercise. Moreover, SI (symmetry index; SI) was calculated from the measured value of SL (step length). Statistical analyses were conducted using one-way ANOVA and two-way ANOVA with repeated measures, a paired t-test, and multiple comparisons according to Scheffe. Results: In the muscle activity, ST decreased significantly in short step length(S-SL) and BG of LS compared to before isometric exercise(p<.05), and GCM decreased significantly in BG of S-SL(p<.05). As for body balance ability, the mSEBT-A difference between L-SL and S-SL was decreased significantly in UG(p<.05). And the respective total scores of L-SL and S-SL, mSEBT-PM and mSEBT-PL were increased significantly in BG(p<.05). Conclusions: As a result, in this study above, it was confirmed that isometric exercise improved muscle activity and body balance ability in asymmetrical walkers.

Original Article : Effects of balance imagery of semi-tandem stance on a flat floor and balance beam for postural control: a comparison between older and younger adults

( Jeong-weon Lee ),( Su Jin Hwang ) 물리치료재활과학회 2015 Physical therapy rehabilitation science Vol.4 No.2

Objective: Balance is a preceding task for functional activities in daily activities as well as community-dwelling activities. Tolearn skilled and functional activities, it is also necessary to imagine an appropriate and effective movement representation used to plan and execute the functional activities. The purpose of this study was to evaluate the effects of balance imagery of semi-tandem stance on a flat floor and balance beam on balance abilities for elderly and young adults. Design: Cross-sectional study. Methods: Fifteen elderly and thirty-four young adults were enrolled in this study. In order to determine whether there is a change in postural control ability according to the different imagery training methods used, standing static balance measurements were performed. According to the therapist``s instructions, participants were to stand in a semi-tandem position on the Good Balance System for 1 minute while imagining that they were standing on a balance beam, and while the postural control abilities was assessed. Results: Postural control was significantly different in balance ability of semi-tandem stance on a flat floor compared to on a balance beam in both geriatrics and young adults. Postural sway was more significantly decreased in young adults than older adults during balance imagery of semi-tandem stance on a flat floor as well as on balance beam (p<0.05). Conclusions: The results of this study suggest that the ability to mentally represent their actions was similar in older adults compared to young adults, although older adults showed a drop in efficiency of postural control more than young adults.

Contralateral Pedicular Fracture with Unilateral Spondylolysis

Jeong, In-Ho,Hwang, Eai-Hong,Bae, Weon-Tae The Korean Neurosurgical Society 2009 Journal of Korean neurosurgical society Vol.46 No.6

Although most authors regard contralateral pedicular fracture with unilateral spondylolysis as an unstable condition and recommend surgical management when immobilization fails in promoting bony healing of the fracture, few researchers have investigated the natural history of pedicle fracture or the causal relationship between symptoms and the fracture. In addition, there are no detailed guidelines that address the management of this disease. We report a rare case of contralateral pedicular fracture associated with unilateral spondylolysis at the L5 level which was successfully treated by rehabilitation with activity modification.

국산 마가린의 물리화학적 성질 및 지방산 조성에 관한 연구

황인경,안승요,김정원 한국조리과학회 1986 한국식품조리과학회지 Vol.2 No.1

Physicochemical properties and fatty acid composition of 12 randomly selected Korean margarines were determined, which were stored within one month since manufactured. Average moisture and fat contents of margarines were 15.09% and 77.92% respectively. Melting point was ranged from 33.23℃ to 42.13℃. Acid value and peroxide value were very low. Iodine value was ranging from 59.65 to 86.05. As a result of cluster analysis using the data of fatty acid composition, margarines divided into two groups according to their package condition, soft and hard type, were also classified into the same two groups. This probably implies that the raw materials of margarines between two groups were not the same. Oleic acid (18:1) and palmitic acid (16:0) in soft and hard type margarines respectively were the highest. Linoleic acid (18:2) contents showed large differences among margarines. Most of the margarines had little linolenic acid (18:3). Generally essential fatty acid contents of Korean margarines were higher than those of the past but they didn't reach the levels of margarines made in some foreign countries.

Neural activity during simple visual imagery compared with mental rotation imagery in young adults with smartphone overuse

Hwang, Sujin,Lee, Jeong-Weon,Ahn, Si-Nae korean Academy of Physical Therapy Rehabilitation 2017 Physical therapy rehabilitation science Vol.6 No.4

Objective: This research investigated the effects of simple visual imagery and mental rotation imagery on neural activity of adults who are at high risk of smart phone addiction by measuring their electroencephalography (EEG). Design: Cross-sectional study. Methods: Thirty people with a high risk of smart phone addiction was selected and then were evaluated for their neural activation patterns using EEG after reminding them about simple visual imagery and mental rotation imagery. A simple visual image was applied for 20 seconds using a smartphone. This was followed by a resting period of 20 seconds. Mental rotation imagery was applied for 20 seconds. During mental rotation imagery, the rotational angle was selected at random. We compared activation patterns according to the analyzed EEG with hemisphere reminding them about imagery. Results: On the EEG, theta rhythm from the left hemisphere parietal area increased when the subjects were reminded of mental rotation imagery, and sensorimotor rhythm from close to the left hemisphere area increased when the subjects were reminded of simple visual imagery. Conclusions: Neural activation from the left hemisphere occurs for motor imagery in adults who are at high risk of smart phone addiction. These results identify a neural mechanism of adults who a have high risk of smart phone addiction, which may provide contribute to the development of motor rehabilitation for smartphone users.

Changes in Antioxidant Enzymes, According to Recovery Methods During Repeated Apnea Diving

Hwang-woon MOON,Youn-sang SONG,Jeong-Weon KIM 한국식품보건융합학회 2021 식품보건융합연구 (KJFHC) Vol.7 No.4

This study analyzes the physiological changes that occur after free diving and studies peroxidants and antioxidants according to the recovery method. Accordingly, the purpose of this study is to provide proper rest methods after free diving and provide basic data for free diving research. Eight male college students recovered for 30 minutes after 20 free injections at a 5-meter diving site, 20 free injections after a week s car wash, and recovered for 30 minutes after collecting blood during recovery to analyze the effects of peroxidants and antioxidants. Comparison of changes in peroxidants and antioxidants in recovery methods after free-diving iterations showed that SOD tended to decrease immediately after free-diving, increasing MDA to 10 minutes after recovery, but no significant difference was found. The purpose of this study is to observe physiological changes according to the recovery method after free diving and to propose an appropriate recovery method after free diving. However, there was no significant difference in all the restoration methods, and 20 freediving was not high kinetic intensity for the subjects, which is believed to have resulted in the following results. Therefore, it was discussed that the repetitive diving strength should be higher to confirm a significant difference in the recovery method after free diving.

소아개심술시 체외순환 종료직후 우심방혈과 폐동맥혈 산소포화도의 비교

황정태,안원식,염광원,김성덕 대한마취과학회 1997 Korean Journal of Anesthesiology Vol.33 No.4

Background : Mixed venous oxygen saturation(SO2) monitoring turned out to be invaluable in following up systemic cardiovascular status. But balloon-tipped flow-directed thermodilution catheter (Swan-Ganz catheter) insertion carries additional inherent risks other than those of central venous catheterization, and it costs much more expense than simple venous catheter. There has been a lot of papers which argue that central venous catheterization may substitute for the Swan-Ganz catheterization. In addition, it may be very difficult or impossible to insert the Swan-Ganz catheter in pediatric patients. This study was performed to determine whether Swan-Ganz catheterization might be replaced by the central venous catheterization in regards to SO2. Methods : In 17 pediatric open heart surgery(OHS) patients, from the central venous catheter, the tip of which had been located in the center of right atrium(RA) and pulmonary artery, blood samples were drawn for gas analysis simultaneously, which was done immediately after emergence from cardiopulmonary bypass. Results : There were no significant differences between RA blood and mixed venous blood gas analyses except oxygen saturation. The oxygen saturations of both were linearly correlated with each other. The relation was SO2=17 0.8 SRAO2(R=0.77, p<0.05) Conclusions : It may be concluded that RA blood may be used for blood gas analysis in place of mixed venous blood immediately after pediatric open heart surgery. (Korean J Anesthesiol 1997; 33: 664∼668)