• 대한물리치료과학회지
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• 제11권1호
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• pp.28-35
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• 2004

The purpose of the present study was to investigate the effectiveness of silver spike point (SSP) low frequency electrical stimulation on glomerular filtration rate (GFR), specifically, such as diuretic action in 24 hour urine and in plasma analysis from normal volunteer. The current of 1 Hz continue type (CT) of SSP low frequency electrical stimulation significantly decreased in plasma creatine from normal volunteer. However, the urine creatinine clearance (Ccr) was significantly increased by SSP low frequency electrical stimulation in normal volunteer. These results suggest that the SSP low frequency electrical stimulation, especially current of 1 Hz continue type, significantly regulates urine creatinine clearance and glomerular filtration rate from normal volunteer. Therefore, the SSP low frequency electrical stimulation is a good regulator through a diuretic action of hypertension.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.143-145
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• 2015

A mesoscale channel was designed to observe the flame stabilization at low strain rate conditions (< $10s^{-1}$). At this condition, the behavior of partially premixed flame was explored by changing a channel size and the oxygen ratio in the oxidant. In this work, experiment is conducted for propane case and it was compared with methane case of previous one. Conclusively, it can be observed that the strain rate of flame extinction and starting point of oscillation were varied with oxygen ratio. Moreover we can understand the effects of enhanced oxygen ratio of oxidant and flame behavior at low strain rate conditions.

• 정보와 통신
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• 제11권8호
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• pp.60-77
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• 1994

This paper presents a survey of video coding schemes which use wavelet transform for the videophone on very low bit rate commun ication chan nel( ego 10 Kbps Public Service Telephone Network). Firstly, we introduce the standardization efforts to make the low bit rate videophone architecture and the typical application of low bit rate video coding scheme. Secondly, we summarize the several requirements on videophone, delay, encoder/decoder complexity, low bitrate, and progressive transmission capability. Third, we review the basic theory of wavelet transform without much mathematics. We compare the wavelet transform with short-time fourier transform and subband filters. Fourth, we summarize the video coding schemes proposed so far, and evaluate them with Ule requirements. Lastly, we conclude with fu¬ture research directions.

• 전기전자학회논문지
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• 제2권2호
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• pp.233-238
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• 1998

본 논문에서는 G.726 ADPCM 음성방식을 기존의 단일 압축을 대신 16Kbps 와 40Kbps의 두 가지 압축율을 사용한 가변 압축방식에 의한 음성 코딩 방식을 다루었다. 음성의 묵음 또는 소 신호 부분은 음질의 향상보다는 데이터 비트 수를 줄이기 위한 저 전송 16Kbps 압축율을 적용하였고 임계값 이상의 대 신호 부분은 음질을 향상하기 위하여 40Kbps의 압축율을 적용하여 모든 신호를 단일 압축율로 코팅하는 방식에 비하여 전체적으로 압축율을 높여 전송 비트 수를 줄이면서 음질을 저하시키지 않도록 하였다. 분 논문에서는 시뮬레이션을 통하여 여러 가지의 임계값에 의한 가변 압축 코딩 방식에 대하여 압축율과 음질의 관계 를 다루었다. 또한 고정된 임계값에 대하여 입력 음성의 크기를 여러 가지로 변동하여 주변 배경잡음과 포화에 의한 음질의 저하를 고찰하여 가변 율에 의한 음성의 코딩방식에서 임계값과 입력의 크기가 음질 및 압축율에 미치는 영향을 다루었다. 각 시뮬레이션의 경우에 대하여 실지 음성의 원음에 대한 음질의 충실 도를 임의의 집단에 대하여 비교하여 음질의 충실 도를 확인하였다. 추후의 연구를 통하여 DSP에 의한 실시간 처리 시스템의 구현을 하고자 한다.

• Journal of Welding and Joining
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• 제15권2호
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• pp.72-80
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• 1997

The spatter generation rate of GMA welding with $CO_2$ gas shielding was measured with the change of welding conditions such as wire feeding rate and welding voltage and then the results were analized with the accompanying changes in metal transfer mode and in bead geometry. The spatter generation rate (SGR) was relatively low not only wit the short circuit transfer but with the truely globular transfer mode. However, the SGR resulted with the mixed mode were consistantly high. The resultant wave pattern of mixed mode was due to the coexistance of short-circuit and globular transfer and characterized by the frequent appearance of instantaneous short circuit. Considering the result of SGR and that of bead geometry, it could be concluded that when the wire feeding rate (or welding current) was either low or high, the optimum bead shape could be obtained along with the low spatter generation. However, in the middle range of wire feeding rate, the optimum bead shape was only obtained in the mixed mode condition resulting in the high spatter generation.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.113-118
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• 2002

Wave overtopping is one of the most important hydraulic responses of breakwater because it significantly affects its functional efficiency, the safety of transit and mooring on the rear side, wave transmission in the sheltered area, rear side armor stones and to some extent, the structural safety itself. The hydrodynamic characteristics of low crest breakwater by the overtopping rate can be summarized as follows: 1. It is better to use maximum overtopping rate than to use mean overtopping rate for design of coastal structures. 2. Maximum overtopping rate was increase with wave steepness (between 0.01 and 0.02). 3. Overtopping rate is decreased when relation length of berm was over wave length.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.240-245
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• 2000

Fatigue crack propagation rates and characteristics of the SA516-60 steel which is used for the low temperature pressure vessels, were studied in the room temperature of $25^{\circ}C$ and low temperature ranges of $10^{\circ}C,\; -10^{\circ}C,\; -30^{\circ}C,\; -50^{\circ}C, \;and\; -70^{\circ}C4 with stress ratio of R=0.05. The obtained experimental results are as follows; 1) In the logarithmic relationship between the fatigue crack propagation rate(da/dN) and stress intensity factor K, the linear relationship was obtained up to da/dN 〉$8\times10^{-3}$/mm/cycle in the same of room temperature, but in low temperature case, the relationship was extended to the range of crack propagation rate. 2) The lower limit stress intensity factor of SA516-60 $\DeltaK_{th}$ was 15.8MPa and in the case of low temperature $-50^{\circ}C\; and\; -70^{\circ}C$, the crack propagation rate da/dN which showed a linear relation, reached rapidly to the $\DeltaK_{th}$/. As the results, the crack propagation rates of $-50^{\circ}C\; and\; -70^{\circ}C$ were lower than that of room temperature and according to the testing temperature the rates were decreased rapidly to the $\DeltaK_{th}$/. 3) On the relationship between the stress intensity factor $\DeltaK$ and the crack propagation cycle, the stress intensity factors of low cycle region was rapidly increased at low temperature, but $\DeltaK$ was increased rapidly at room temperature of high cycle. 4) On the relationship between the fatigue crack propagation rate and cycle, the fatigue crack propagation rate showed higher gradient in the room temperature than the low temperature due to the increment in ductility at low temperature.

• 한국산업보건학회지
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• 제22권2호
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• pp.107-118
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• 2012

Objectives: This study examines the occurrence of disease resulting from low back pain and factors of working environment meaningfully influencing the occurrence of lumbago as well as analyzes '2nd Korean Working Condition Survey (KWCS)' conducted in 2010 so as to establish the prevention and improvement measures. Methods: The analysis method is that it is to compare the prevalence rate of low back pain according to working environment via odds ratio and to implement the test about the factors having the difference in working environment between low back pain group and normal group through weighted t-test. Results: As a result, it indicates that there is a meaningful difference for prevalence rate of low back pain according to age, status in employment and education level which are socio-demographical factors. The analysis in working hours shows that the period of work is a factor raising the prevalence rate of low back pain rather than weekly working hours. The analysis in the work risk factor indicates that the increase in prevalence rate of low back pain takes place to either workers with repetitive movement and continuously standing posture or those with heavy stress and emotional labour. Conclusions: Workers with low back pain have suffered from accident, depression, anxiety disorder and sleep. The factors in which the prevalence rate of low back pain decrease are to provide information on health and safety and working speed, and enough rest.

• 지역사회간호학회지
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• 제9권1호
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• pp.213-222
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• 1998

The prevalence rate of low back pain in nurses is higher than that of other jobs, because there are many more risk factors(for example, standing postures, lifting and carrying heavy loads, transfering patients, changing a patient's position etc.). This investigation is to provide basic data for prevention of low back pain by analyzing the prevalence rate and related factors of low back pain in nurses(esp. operating room staff) in general hospitals. A self-reported questionaire survey was carried out on three hundred and five nurses of three general hospitals in Seoul from June, 1996 to August, 1996. Subjects of the survey were divided into a low back pain group(LBP) and a cotrol group to investigate the association between low back pain and the general characteristics and work related factors of each group. The results were as follows: 1. In the subjects of the survey, the prevalence rate of low back pain was 60.0% for the last year. 2. 73.6% of operating room(OR) staff complained of low back pain. 3. Standing for a long time and working in twisting postures were associated with low back pain, and so were the shift, the type of work, and the frequency of transfering patients. 4. The weight loads which nurses frequently carried were, under 5kg, 5-10kg, 15-20kg, 15-20kg, over 20kg, and all, except for 10-15kg, were associated with LBP. 5. 76.9% of the LBP experienced low back pain within 3 years after starting nursing jobs. 6. Concerning the degrees of low back pain: 75.8% was limited to waist; 18.8% reached the knees; 4.2% reached ankles. In conclusion, the prevalence rate of low back pain in general hospital nurses was associated with the works in operating room and other work related factors, therefore it is necessary to develop on educational program for the prevention of low back pain as well as and to improve working environments.

• 아시안잔디학회지
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• 제13권1호
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• pp.1-20
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• 1999

This study was carried out to investigate the interaction between productivity and light condition and to analyze the material productivity and productive charactaristics under different hours of light in Zoysia japonica. 1. Rate increasement of leaf number and total leaf length was remarkably high at the early growth stage in the control and 9 hour light treatment. The rate gradually decreased as growth proceeded. But 3 hour treatment was very low in the rate from its early growth stage through the whole test period. 2. The increasing rate of leaf area ratio (LAR) in all the experimental plots was remarkably high at the early growth stage after transplanting the grass. The shorter photoperiod resulted remarkable lower increasement of LAR. 3. The rhizome growth rate of the 9 hour photoperiod was high contrast to the 3 hour photoperiod treatment. The increasing rate of node number was also showed similar trend. 4. Chlorophyll content was very high at the 36 days after transplanting and then decreased gradually. Chlorophyll content on 3 hours photoperiod plot severely decreased. The ratio of chlorophyll a to b was decreased significantly at short day treatment. 5. The content of soluble sugar was increased at shorter photoperiod. The highest ratio of sugar content was on August, 28 by HPLC method. Such a result was attributed to accumulation of sugar in spite of low synthesis of ploysacchrides, translocation by low consumption. 6. The increasing rate of standings in all light treatment was high at the early growth stage after transplanting. Short photoperiod treatment by 3hour showed especially low prganic productivity on Zoysia japonica.