• 한국측량학회지
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• 제18권4호
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• pp.369-378
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• 2000

본 연구는 구조물 안전진단 기초자료인 변위를 GPS를 이용하여 측정하는데 목적이 있으며, 실험대상인 금강 남측 도류제상에 설치한 2점의 변위관측점을 약 1년간 4개월 주기로 4？의 GPS 장비로 측정하여 그 3차원적 정적변위를 측정하였다. 또한, 보다 신뢰성 있는 해안구조물의 변위측정기법을 모색하기 위하여 기준점과 좌표계의 선정에 따른 변위관측정확도와 GPS관측변위의 신뢰성을 점검하는 방안에 대하여 검토하였다.

• 한국정밀공학회지
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• 제17권11호
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• pp.75-80
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• 2000

Recently, there are a great many research for magnetic levitation system. In case electromagnet is operated as the actuator of control system, first of all, we must analysis about an electromagnet. Important parameters of this system are inductance(L) and resistance(R) which are induced from the coil of electromagnet. And attractive force equation is also important. If the load of this system is large, phase delay is caused by self-inductance effect. Because this delay effect cause stability of whole magnetic evitation system to grow worse, a measures to diminish time constant must have been taken. And the linearized attractive force equation which is used at small range of the operating point is compensated to use at larger range, thus the experiment of magnetic levitation system will get a better result.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 추계학술대회 논문집
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• pp.123-124
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• 2015

Recently interest on DC systems has been grown up extensively for more efficient connection with renewable energy. During the operation, there happens DC_link voltage variations. This paper focuses on the DC voltage stabilization applied in stand-alone DC microgrid to improve the system stability by keeping the voltage within limits. Batteries and a variable speed diesel generator cover the shortage of power after all available renewable energy is consumed. Load shedding or power generation reduction should automatically takes place if the maximum tolerable voltage variation is exceeded. PSIM based simulation results are presented to evaluate the performance of the proposed control measures.

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.8-14
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• 2020

Intelligent devices using ICT technology have been introduced in the field of construction machinery to improve productivity and stability. Among the intelligent devices, Machine Guidance is a device that provides real-time posture, location, and work range to drivers by installing various sensors, controllers, and satellite navigation systems on construction machines. Conversely, the efficiency of equipment that requires location information, such as machine guidance, will be greatly reduced in buildings, and tunnels in the GPS blind spots. Thus, the other high-precision positioning technologies are required in the GPS blind spot zone. In this study, we will develop a relative position measurement system that provides precise location information such as construction machinery and robots in a local area where the GPS reception is difficult. A relative position measurement system tracks a marker in the form of a sphere installed on a vehicle by using the image base tracking technology, and measures the distance and direction information to the marker to calculate a position.

• 한국산학기술학회논문지
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• 제16권2호
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• pp.1189-1199
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• 2015

본 연구의 목적은 산부인과 전신마취 수술환자의 불안과 활력징후에 선호음악이 미치는 효과를 검증하는 것이다. 연구 설계는 비동등성 대조군 전후 시차설계이다. 연구기간은 2013년 5월 1일부터 7월 30일까지이며, 대상자는 W대학병원의 산부인과 수술환자로 실험군 21명, 대조군 23명, 총 44명이다. SPSS Win 18.0을 활용하여 Repeated measures ANOVA로 자료를 분석하였다. 연구 결과 선호음악을 제공받은 실험군과 제공받지 않은 대조군 간의 불안은 수술실 입실 시와 마취직전 사이 및 마취 직전과 의식 회복 후(p=.003; p=.011)의 시점에서 유의한 차이를 보였다. 수축기 혈압은 의식 회복 후와 회복실 퇴실 시 사이에 유의한 차이를 보였으며(p=.023), 맥박은 마취 직전과 의식 회복 후 사이에서 유의한 차이가 있었다(p=.016). 향후 선호음악 요법은 산부인과 전신마취 수술환자의 불안 감소 및 안정된 활력징후를 유지를 위한 효과적인 간호중재로 적용될 수 있다.

• 한국기계가공학회지
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• 제14권6호
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• pp.129-135
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• 2015

This paper shows significant methods that improve the lifespan of LED modules as well as efficiently using an aluminum heat-sink for LED module in high power. It proposes a method that raises stability and lifespan to protect LED modules and the power unit when the LED module has been used for a long hours at high temperatures. During the research, we applied a method of pulse-width modulation (PWM) in order to prevent the phenomenon that the entire power of a system is turned off and the lifespan is reduced when the LED nodule reacts to the high temperatures. To protect the LED module and SMPS based on high efficiency, a temperature sensor is attached underneath the circuit board and the sensor measures the temperature of circuit board when the LED module is powered on. The electrical power connected to SMPS is controlled by PWM when the temperature of the LED module reaches a particular temperature.

• 대한정형도수물리치료학회지
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• 제15권2호
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• pp.80-87
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• 2009

Purpose: This study was to determine the effects of a early exercise program on the pain, disability and balance after single-level lumbar discectomy. Methods: Forty patients were randomized into experimental(N=20) and control(N=20) groups. Three days after surgery, patients in the experimental group undertook a 4-week exercise program. Assessments were performed in all patients during the week before surgery and at 4 weeks after. The assessment included measures of back and leg pain(VAS), Oswestry disability index(ODI), stability index(SI) and weight distribution index(WDI). Results: At 4 weeks, VAS, ODI, SI, WDI were significantly reduced in both groups(p<.01). Also the experimental group was significantly reduced back and leg pain(VAS), ODI and WDI were better than the control group(p<.05). Conclusion: It seems that early exercise program is more effective in patients who undergo single-level lumbar discectomy.

• 농업과학연구
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• 제49권3호
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• pp.679-690
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• 2022

As the supply and demand of pork has become a significant concern in Korea, controlling it has become a critical challenge for the industry. However, compared to the demand for pork, which has relatively stable consumption, it is not easy to maintain a stable supply. As the preparation of measures for a supply-demand crisis response and supply control in the pig industry has emerged as an important task, it has become necessary to establish a stable supply model and create an appropriate manual. In this study, a pork supply prediction model is constructed using reported data from the pig traceability system. Based on the derived results, a method for determining the supply-demand crisis stage using a statistical approach was proposed. From the results of the analysis, working days, African swine fever, heat wave, and Covid-19 were shown to affect the number of pigs graded in the market. A test of the performance of the model showed that both in-sample error rate and out-sample error rate were between 0.3 - 7.6%, indicating a high level of predictive power. Applying the forecast, the distribution of the confidence interval of the predicted value was established, and the supply crisis stage was identified, evaluating supply-demand conditions.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.75-83
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• 2013

PURPOSE. Maxillofacial silicone elastomer is usually colored intrinsically with color pigments to match skin colors. The purpose of this study was to investigate the color stability of a maxillofacial silicone elastomer, colored with a thermochromic, color changing pigment. MATERIALS AND METHODS. Disc-shaped maxillofacial silicone specimens were prepared and divided into 3 groups: a conventionally colored control group, one group additionally colored with 0.2 wt% thermochromic pigment, and one group with 0.6 wt% thermochromic pigment. Half of the surface of each specimen was covered with an aluminium foil. All of the specimens were exposed to UV radiation in 6 hour cycles over 46 days. In between the UV exposures, half of the specimens were stored in darkness, at room temperature, and the other half was stored in an incubator, at a humidity of 97% and a temperature of $+37^{\circ}C$. Color measurements were made with a spectrophotometer and registered according to the CIELAB $L^*a^*b^*$ color model system. The changes in $L^*$, $a^*$ and $b^*$ values during artificial aging were statistically analyzed by using paired samples t-test and repeated measures ANOVA. P-values <.05 were considered as statistically significant. RESULTS. The UV exposure resulted in visually noticeable and statistically significant color changes in the $L^*$, $a^*$ and $b^*$ values in both of the test groups containing thermochromic pigment. Storage in the incubator lead to statistically significant color changes in the $a^*$ and $b^*$ values of the specimens containing thermochromic pigment, compared to those stored at room temperature. CONCLUSION. The specimens containing thermochromic pigment were very sensitive to UV radiation, and the thermochromic pigment is not suitable, as such, to be used in maxillofacial prostheses.

• PNF and Movement
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• 제16권3호
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• pp.405-414
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• 2018

Purpose: The purpose of this study was to examine test-retest reliability and criterion-related validity of a trunk stability robot when measuring the weight-bearing symmetry static sitting and standing in stroke patients. Methods: For 27 stroke patients, weight-bearing symmetry was assessed twice, 7 days apart. The intraclass correlation coefficient (ICC2,1) and minimal detectable change (MDC) were used to examine the level of agreement between test and retest. The criterion-related validity of weight -bearing symmetry was demonstrated by Spearman correlation of modified Barthel index (MBI), the sit to stand test (STS), the timed up & go Test (TUG), and the function in sitting test (FIST). Results: the test-retest agreements were excellent for the weight-bearing symmetry of static sitting (ICC2,1: 0.90) and standing (ICC2,1: 0.89). It all showed that the acceptable MDC for the weight-bearing symmetry of static sitting and standing was 0.11 and 0.16, respectively (highest possible score<20 %), indicating that the measures had a small and acceptable degree of measurement error. The weight-bearing symmetry of static sitting was significantly correlated with the TUG(r=-0.45) and FIST(r=0.46)(p<0.05); the weight-bearing symmetry of static standing was also significantly correlated with MBI (r=0.65), TUG (r=-0.67), FIST (r=0.61)(p<0.01), and STS (r=-0.47)(p<0.05). Conclusion: The weight-bearing symmetry of static sitting and standing assessed by the trunk stability robot showed highly sufficient test-retest agreement and mild-to-moderate validity. It could also be useful for clinicians and researchers to evaluate balance performance and monitor functional change in stroke patients.