• Journal of Life Science
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• v.14 no.4
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• pp.573-576
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• 2004

The purpose of the present study is to investigate the lipid peroxidation, creatine kinase activity and cortisol hormone levels following the training intensity in elite judo players. Six elite Judo players participated in the experiments (3h repetition judo program), which include stretching, judo skill practice and cool down without recess. Blood sampling were taken at the judo gymnasium at the time of resting, 1h training, 2h training, 3h training, 2h recovery, and 24h recovery time and this were analyzed for CK, MDA and Cortisol levels. The results obtained were analyzed via repeated measures of ANOVA using SPSS package program (ver.10.0) and a value of p<.05 was considered statistically significant. The results from this study were as follows. In the CK levels, which reflect the contribution of creatine phosphate and muscle damage degree, there was a significant difference (p<.05) after judo training in every period. Recovery 24h showed the highest level. In the MDA levels, which reflect lipid peroxidation, there was a significant difference (p<.05) after judo training. Recovery 2h showed the lowest level. In the cortisol hormone levels, which reflect stress status, there was a significant difference (p<.05). In this study, we can conclude that For the trained athletes, MDA level was lower at the time of exercise compare to the other period, this is caused by the increased antioxidant defence mechanism.

• Korean Journal of Rural Living Science
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• v.9 no.2
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• pp.43-50
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• 1998

To obtain basic data for efficient health plan, we investigated the condition of farmers' health, living behavior, working environment, and cumulative fatigue symptoms by crops (greenhouse melon, rice and red pepper, stock farming, pear, grapes, dropwort, sweet potato, potato, radish. cabbage). The results are as follows; (1) The condition of farmers health : Among them, cabbage cultivators were in bad health concerning cardiovascular system, musculo-skeletal system, and skin condition. (2) Living behavior : $\circled1$ Radish cultivators were in best of their physical condition. $\circled2$ Rice and red pepper cultivators were taking a regular recess as compared with dropwort cultivators. $\circled3$ On concerning bathe, sleeping, and clothes, stock farmers were in relatively bad condition. (3) Working environment : cabbage, greenhouse melon, and dropwort cultivators had relatively Poor working environment. (4) Cumulative fatigue symptoms : $\circled1$ Dropwort cultivators were in the worst of their condition concerning loss of their energy, physical condition. decline of will to labor, sense of unease, and low spirits. $\circled2$ On concerning general fatigue, dropwort, sweet potato, and cabbage cultivator were in bad condition.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.31-36
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• 2007

Combustion performance characteristics of subscale high-pressure combustor were investigated at 70 bar combustion pressure. All tests were successfully performed without any damage on the combustor. The mixing characteristics and distribution pattern of the injectors were found to have considerable influence on the combustion performance. The characteristic velocity of the combustor was higher in the injector with internal mixing than that of external mixing and in the injector with smaller mass flowrate. The pressure fluctuations at the propellant manifolds and the combustion chamber were measured to be less than 3% of the mean combustion pressure to meet the combustion stability criterion and to prove stable combustion characteristics of the combustor.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.228-233
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• 2004

The spray and acoustic characteristics by the self-oscillation of a swirl coaxial injector were experimentally studied. The self-oscillation of a swirl coaxial injector is defined as pressure and flowrate oscillations by a time-delayed feedback between liquid and gas phase and has strong influences on atomization and mixing processes. Hence the occurrence and effect of the self-oscillation are measured using shadow photography technique, acoustic test and PDPA. The occurrence of self-oscillation largely depends on the injection conditions, such as pressure drop of liquid phase and relative momentum ratio. From the experimental results, self-oscillation occurs when the momentum of gas phase is enough large and the smaller the pressure drop of liquid phase is, the better self-oscillation occurs at the same momentum ratio. The self-oscillation is also affected by injector geometries, increasing the recess length results in the expansion of self-oscillation region and the increase of sound pressure level. The self-oscillation of a swirl coaxial injector accompanies a high intensity scream and this scream may provide harmful disturbances to combustion processes. Self-oscillation leads to strong changes in the drop size distribution and smoothly varies the slope of radial SMD distribution.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.568-574
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• 2000

We have been optimized tungsten(W) plug CMP(chemical mechanical polishing) characteristics using two different kinds of component of slurry and two different kinds of pad which have different hardness. The comparison of oxide film roughness on around W plug after polishing has been carried out. And W plug recess for consumable sets and dishing effect at dense area according to the rate of over-polishing has been investigated. Also the analysis of residue on surface after cleaning have been performed. As a experimental result we have concluded that the consumable set of slurry A and hard pad was good for W plug CMP process. After decreasing the rate of chemical reaction of silica slurry and adding two step buffering we could reduce the expanding of W plug void however we are still recognizing to need a more development for those kinds of CMP consumables.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.101-108
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• 2017

This study attempted to improve the accuracy of streamflow and baseflow prediction of Soil and Water Assessment Tool (SWAT) by applying baselfow recession constants for each sub-watershed. This study set two different scenarios (S1 and S2) to evaluate the impact of application of baseflow recession constants for each sub-watershed on streamflow prediction. In S1, Only the baseflow recession constant obtained from the streamflow station located in the final outlet of study area was applied for whole sub-watersheds. In S2, baseflow recession constants obtained from six different streamflow stations were applied for each sub-watershed. Then, baseflow was separated form the measured streamflow data and the predicted streamflow of S1 and S2 using Web-based Hydrograph Analysis Tool (WHAT). The results showed Nash-Sutcliff efficiency (NSE) and $R^2$ of S2 were a little higher than these of S1 in both streamflow and baseflow prediction results. However, it is important that S2 reflected physical meaning of baseflow recess. Also, recession part of hydrograph in S2 was calibrated better than that of S1 compared to the measured hydrograph.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.219-219
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• 2010

기존의 플로팅 타입의 메모리는 소자의 소형화에 따른 인접 셀 간의 커플링 현상과 전계에 따른 누설전류의 증가 등과 같은 문제가 발생한다. 이에 대한 해결책으로서 전하 저장 층을 폴리실리콘에서 유전체를 사용하는 SONOS 형태의 메모리와 NFGM (Nano-Floating Gate Memory)연구가 되고 있다. 그러나 높은 구동 전압, 느린 쓰기/지우기 속도 그리고 10년의 전하보존에 대한 리텐션 특성을 만족을 시키지 못하는 문제가 있다. 이러한 문제를 해결 하고자 터널베리어를 엔지니어링 하는 TBM (Tunnel Barrier Engineering Memory) 기술에 대한 연구가 활발히 진행 중이다. TBM 기술은 터널 층을 매우 얇은 다층의 유전체를 사용하여 전계에 따른 터널베리어의 민감도를 증가시킴으로써 빠른 쓰기/지우기 동작이 가능하며, 10년의 전하 보존 특성을 만족 시킬 수 있는 차세대 비휘발성 메모리 기술이다. 또한 고유전율 물질을 터널층으로 이용하면 메모리 특성을 향상 시킬 수가 있다. 일반적으로 TBM 기술에는 VARIOT 구조와 CRESTED 구조로 나눠지는데 본 연구에서는 두 구조의 장점을 가지는 Staggered tunnel barrier 구조를 $Si_3N_4$와 HfAlO을 이용하여 디자인 하였다. 이때 HfO2와 Al2O3의 조성비는 3:1의 조성을 갖는다. $Si_3N_4$와 HfAlO을 각각 3 nm로 적층하여 리세스(Recess) 구조의 트랜지스터를 제작하여 차세대 비휘발성 메모리로써의 가능성을 알아보았다.

• Journal of Korean Neurosurgical Society
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• v.56 no.3
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• pp.206-210
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• 2014

Objective : Lumbar spinal stenosis is a common degenerative spine disease that requires surgical intervention. Currently, there is interest in minimally invasive surgery and various technical modifications of decompressive lumbar laminectomy without fusion. The purpose of this study was to present the author's surgical technique and results for decompression of spinal stenosis. Methods : The author performed surgery in 57 patients with lumbar spinal stenosis between 2006 and 2010. Data were gathered retrospectively via outpatient interviews and telephone questionnaires. The operation used in this study was named central decompressive laminoplasty (CDL), which allows thorough decompression of the lumbar spinal canal and proximal two foraminal nerve roots by undercutting the lamina and facet joint. Kyphotic prone positioning on elevated curvature of the frame or occasional use of an interlaminar spreader enables sufficient interlaminar working space. Pain was measured with a visual analogue scale (VAS). Surgical outcome was analyzed with the Oswestry Disability Index (ODI). Data were analyzed preoperatively and six months postoperatively. Results : The interlaminar window provided by this technique allowed for unhindered access to the central canal, lateral recess, and upper/lower foraminal zone, with near-total sparing of the facet joint. The VAS scores and ODI were significantly improved at six-month follow-up compared to preoperative levels (p<0.001, respectively). Excellent pain relief (>75% of initial VAS score) of back/buttock and leg was observed in 75.0% and 76.2% of patients, respectively. Conclusion : CDL is easily applied, allows good field visualization and decompression, maintains stability by sparing ligament and bony structures, and shows excellent early surgical results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.245-250
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• 2004

The objective of the present study is to conduct model combustion tests for various injectors to identify their combustion stability characteristics. Three different double swirl coaxial injectors with variation of a recess number have been tested for the comparative study of stability characteristic and flame structure. Gaseous oxygen and mixture of gaseous methane and propane have been employed for simulating actual propellants used for a fullscale thrust chamber. Upon test results, the direct comparison between various types of injectors can be realized for the selection of the best design among prospective injectors.

• Journal of the Korean Institute of Educational Facilities
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• v.25 no.6
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• pp.21-28
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• 2018

To compare the physical quantity of students circulation along the moving path during recess of a variation type operation middle school, five points were actually observed. The flow coefficient for these points was calculated, and the change in flow coefficient was verified and tracked over time. During the operation of the classroom, the characteristics of crowdedness and congestion time depending on the physical conditions of the frequently moved paths were shown. Even in the same corridor, the difference between the flow coefficient and the congestion time of the corridor facing the open space and the blocked space was noticeably different. As a result, detailed factors such as free walking speed, the degree of freedom of passing and the possibility of collision were also identified. This means that detailed countermeasures for the student's path should be considered first when planning the moving space of a variation type school, and identifying the characteristics of these factors could be used as useful basic materials for developing various models of classroom space.