• Advances in concrete construction
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• 제16권2호
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• pp.79-89
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• 2023

The occurrence of unexpected horizontal offset in the instrument or target will result in accumulated horizontal deviation in segment alignment with traditional short-line match method. A geometry control method, the four-point method, is developed for precast segmental bridges to avoid the influences of unexpected horizontal offset. The concept of the four-point method is elucidated. Furthermore, the detailed instruments and instructions are introduced. Finally, the four-point method is validated through a practical engineering application. According to the survey data, after short-line match precast construction, the vertical deviations on both sides vary between -5 mm and 5 mm in almost all segments, and the horizontal deviations vary between -4 mm and 4 mm in all segments. Without on-site adjustment, the maximum vertical and horizontal closure gaps are 12.3 and 26.1 mm, respectively. The four-point method is suggested to alleviate the issues associated with relatively poor soil conditions in casting yard.

• 조명전기설비학회논문지
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• 제25권6호
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• pp.35-41
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• 2011

In order to design effectively the grounding system, it is very important to determine the optimum soil resistivity at the desired location of the connection to earth. This paper deals with the reasonable methods of measuring the soil resistivity where grounding electrodes are buried. The soil resistivity at three test sites with different resistivity of soil were measured as functions of the spacing between the test probes in the Wenner's four-point method and the length of test ground rod in the three-point method. In the case of the three-point method, the length of test ground rod of 2-10[m] in length was appropriate in two-layered soil structure. In the length range of 2-10[m], the results measured by the three-point method using the test ground rod with the length corresponding to the spacing between the test probes of the Wenner's four-point method are in good agreement with the data obtained from the Wenner's four-point method.

• 전기학회논문지P
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• 제59권4호
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• pp.423-427
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• 2010

Portable sheet resistance-measuring instrument using the dual-configuration Four-Point Probe method is developed for the purpose of precisely measuring the sheet resistance of conducting thin films. While single-configuration Four-Point Probe method has disadvantages of applying sample size, shape and thickness corrections for a probe spacing, the developed instrument has advantages of no such corrections, little edge effects and measuring simply and accurately the sheet resistance between $0.2\Omega/sq$ and $2k\Omega/sq$.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1045-1046
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• 2011

• 비파괴검사학회지
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• 제21권5호
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• pp.532-541
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• 2001

재료의 노화에 의한 강도 및 인성 감소치를 정량적으로 평가하는 비파괴적 기법의 개발이 시도되고 있으며 전기비저항법도 그 중의 하나이다. 본 연구에서는 전기비저항법의 열화도 평가에의 적용성을 살펴보기 위해 먼저 6종 10 가지의 비자성 금속을 측정시료로 선택하여 직류 two-point probe법(혹은 2탐침법)으로 전기비저항을 계산한 결과와 비접촉식 와전류 방법으로 전기비저항을 측정한 결과를 서로 비교하였다. 또한, 1Cr-1Mo-0.25V강에 대하여 비파괴적 측정 방법인 four-point probe 방법(혹은 4탐침법)을 사용하여 얻은 결과와 기존의 2탐침법을 사용하여 얻은 결과를 서로 비교하여 현장에서의 4탐침 기술의 적용 가능성을 살펴보았다. 1Cr-1Mo-0.25V강에 대하여 2탐침법으로 구한 비저항 값과 4탐침법으로 구한 비저항 측정값의 차이는 0.6%였다. 따라서 4탐침법을 사용하여 현장에서 금속소재의 열화도의 비파괴적 평가가 가능하다고 사료된다.

• 전기학회논문지
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• 제60권7호
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• pp.1434-1437
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• 2011

Precision measurement of silicon wafer resistivity has been using single-configuration Four-Point Probe(FPP) method. This FPP method have to applying sample size, shape and thickness correction factor for a probe pin spacing to precision measurement of silicon wafer. The deference for resistivity measurement values applied correction factor and not applied correction factor was about 1.0 % deviation. The sample size, shape and thickness correction factor for a probe pin spacing have an effects on precision measurement for resistivity of silicon wafer.

• 조명전기설비학회논문지
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• 제20권5호
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• pp.1-8
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• 2006

일반적으로 공동주택의 조도를 측정하여 공간의 평균조도를 분석할 때 KS 5점법과 IES 4점법의 조도측정 및 평균조도 산출방법을 적용한다. 이 측정 방법들은 각각 측정점이 달라 평균값에 차이가 발생하기 때문에 정확한 분석을 위하여 공간의 특성과 재실자들의 활동을 고려하여 선택적으로 적용되어야 한다. 그래서 본 연구에서는 측정된 조도값과 시뮬레이션값을 비교함으로써 평균조도 산출법을 객관적으로 평가하였다. KS 5점법은 조명기구의 직하부 조도를 최대한으로 고려한 측정법으로 국부조도 평가에 적합하며, IES 4점법은 공간의 최대 및 최소 조도값의 배제를 통해 평균적 개념에 더욱 접근한 방법이라 할 수 있다.

• 대한수학회지
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• 제43권6호
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• pp.1253-1268
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• 2006

We develop the upper and lower solutions method for the four point problem relative to second order differential equations in order to obtain the existence of solution.

• 한국재료학회지
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• 제12권6호
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• pp.508-512
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• 2002

$2000{\AA}-SiO_2/Si(100)$ and $560{\AA}-Si_3N_4/Si(100)$ wafers, which are 10 cm in diameter, were directly bonded using a rapid thermal annealing method. We fixed the anneal time of 30 second and varied the anneal temperatures from 600 to $1200^{\circ}C$. The bond strength of bonded wafer pairs at given anneal temperature were evaluated by a razor blade crack opening method and a four-point bonding method, respectively. The results clearly slow that the four-point bending method is more suitable for evaluating the small bond strength of 80~430 mJ/$\m^2$ compared to the razor blade crack opening method, which shows no anneal temperature dependence in small bond strength.

• Journal of Acupuncture Research
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• 제17권4호
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• pp.18-27
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• 2000

There is a acupuncture method which make a difference according to the four seasons, according to body region or depth in skin. We call it Acupuncture follow the four seasons(四時刺法). In several chapters of Huangdineijing(黃帝內經) introduced Acupuncture follow the four seasons. Acupuncture follow the four seasons has two kinds of acupuncture method that is to acupuncture at body region and to acupuncture at five Su points(五兪穴). To use five Su points(五兪穴) according to Yongchu(靈樞) disagree with Nanjing(難經). In Yongchu(靈樞), the five phases property disagree with five Su points(五兪穴), but in Nanjing(難經) the five phases property agree with five Su points(五兪穴). Even if we can acupuncture the same point, there will be the different effect according as what is the purpose of doing acupuncture, and when we do acupuncture. That is to say, we can use apucupuncture for the purpose of prevention in Yongchu(靈樞), and for the purpose of healing the disease in Nanjing(難經). Therefore, because we select the point on the base of meridian Kis origin which spring out, we have to acupuncture Chong point(井穴) in winter according to Yongchu(靈樞). Because we select the point on the base of meridian Kis origin which flowing, we have to acupuncture Chong point(井穴) in spring according to Nanjing(難經). And in the base of five phases' property, the purpose of selecting five Su points(五兪穴) is the prevention according to Yongchu(靈樞), and the healing according to Nanjing(難經). So even though we acupuncture the exactly same Chong point(井穴), we can expect the effect that acupuncture method supply Ki for liver in winter. and the effect that it extract pathogenic Ki(邪氣) from the liver in spring.