• 반도체디스플레이기술학회지
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• 제7권1호
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• pp.11-16
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• 2008

Confocal scanning microscopy is a widely used technique for three dimensional measurements because it is characterized by high resolution, high SNR and depth discrimination. Generally an image is generated by moving one optical probe that satisfies the confocal condition on the specimen. Measurement speed is limited by movement speed of the optical probe; scanning speed. To improve measurement speed we increase the number of optical probes. Specimen region to scan is divided by optical probes. Multi-point information each optical probe points to can be obtained simultaneously. Therefore image acquisition speed is increased in proportion to the number of optical probes. And multiple optical probes from red, green and blue laser sources can be used for color imaging and image quality, i.e., contrast, is improved by adding color information by this way. To conclude, this technique contributes to the improvement of measurement speed and image quality.

• 천문학논총
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• 제30권2호
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• pp.629-631
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• 2015

In this proceedings, preliminary results of the KVN Source-Frequency Phase-Referencing (SFPR) observation of 3C 66A and 3C 66B are presented. The motivation of this work is to measure the core-shift of these 2 sources and study the temporal evolution of the jet opacity. Two more sources were observed as secondary reference calibrators and each source was observed at 22, 43, and 86 GHz simultaneously. Our preliminary results show that after using the observations at the lower frequency to calibrate those at the higher frequency of the same source, the residual visibility phases for each source at the higher frequencies became more aligned, and the coherence time became much longer; also, the residual phases for different sources, within 10 degrees angular separations, follow similar trends. After reference to the nearby calibrator, the SFPRed maps were obtained as well as the astrometric measurements, i.e. the combined coreshift. The measurements were found to be affected by structural blending effects because of the large beamsize of KVN, but this can be corrected with higher resolution maps (e.g. KAVA maps).

• 한국음향학회지
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• 제32권3호
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• pp.237-246
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• 2013

본 논문에서는 캐비테이션 터널에서의 소음계측용 청음기 배열 설계를 위한 최적화 기법을 제안하였다. 제안된 최적설계 기법은 배열 설계인자 및 목적함수 정의 그리고 최적화 알고리즘 적용 등의 내용으로 구성되어 있다. 설계인자 정의는 원형배열, 나선배열, 다중나선배열을 대상으로 하였다. 목적함수는 주엽의 빔폭과 최대 부엽 크기를 동시에 고려할 수 있도록 정의하였다. 최적화 알고리즘으로는 광역 최적화 기법의 일종인 VFSR 기법을 적용하였다. 최적 설계기법을 각 배열에 적용 후 도출된 최적 배열을 대상으로 최대 부엽크기 및 주엽의 빔폭을 분석하였다. 끝으로 캐비테이션 터널 내부의 다중반사를 고려한 빔형성 결과 평가를 통해 본 기법의 유용성을 확인하였다.

• 한국측량학회지
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• 제22권3호
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• pp.217-223
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• 2004

실시간 측위 정확도 향상을 위해 많은 방법들이 수행되고 있다. 그 중에 하나가 위상 데이터를 처리함으로써 정밀한 위치 해를 제공해 주는 Inverted RTK(Real-time kinematic)이다. Inverted RTK 측위를 위해서는 최소 1～2분 정도의 1Hz 관측 데이터와 부가적으로 여러 상시 관측소 및 통신 시스템 그리고 데이터 프로세싱 서버가 필요하다. 실시간 응용을 위해서 L1 코드와 반송파 위상 데이터가 동시에 사용되었으며 모호 정수 추정을 위해 칼만 필터를 사용하였다. 또한 이중 차분된 참 모호 정수는 FARA(Fast Ambiguity Resolution Approach)를 이용하여 결정하였다. 본 연구에서는 다양한 기선에 대한 필드 테스트 수행 결과를 제시하였다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2005년도 추계학술대회 논문집
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• pp.301-306
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• 2005

The purpose of this study is to make clear the cross-ventilation effect by floor plan type in apartment house during summer. The questionnaire survey was carried out during the 26$^{th}$ of August ${\sim}$ the 4$^{th}$ of September 2004. The respondents were 174 residents living in two subject apartment estates. One subject estate (we call A estate) was consisted apartment houses having cross-ventilation floor plan. The other subject estate (we cail B estate) was constructed apartment houses having ordinary floor plan. The field measurements of indoor thermal elements reflecting natural cooling effect by cross-ventilation were carried out at A house in A estate and at B house in B estate. The measurements in two subject houses were taken on simultaneously the 27$^{th}$ of August. The residents living in A apartment estate planed cross-ventilation type show positive responses on thermal sensation and airflow sensation. The averages indoor temperature and air velocity in the A house were 0.9 $^{\circ}$C lower and 0.29 m/s higher than the B house. Therefore, it was found that indoor thermal environment during summer in the house having cross-ventilation floor plan maintained more comfortable than the house having ordinary floor plan by natural cooling effect of cross-ventilation.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2005년도 춘계학술발표대회 논문집
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• pp.267-270
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• 2005

The purpose of this study was to make clear the indoor environmental efficiency of front balcony 'in apartment houses during winter. The field measurements of indoor environmental elements were carried out at an ordinary house with an existing front balcony and a house renovated the front balcony into the living room. The measurements in two-subject houses were taken on simultaneously the 20$^{th}$ ${\sim}$ 21$^{th}$ of January 2003. As results, the averages indoor temperature in the ordinary house and the renovated house were same as 23.6${\circ}$C, and the averages globe temperature in two houses were same as 23.7${\circ}$C. But, estimated heating time of the renovated house was longer than that of the ordinary house. The daily ranges of indoor temperature and globe temperature in the renovated house were wider than the ordinary house. The daily ranges of indoor temperature and globe temperature in the renovated house was longer than that of the ordinary house. The uniformity ratio range of daylight in the ordinary house were calculated at 1/3.4${\sim}$1/6.2, but those of the renovated house were 1/6${\sim}$1/16.2. Therefore. it was found that indoor temperature, globe temperature and uniformity ratio of daylight in the ordinary house maintained more constant than the renovated house by green house effect and earning effect of front balcony.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2005년도 춘계학술발표대회 논문집
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• pp.212-216
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• 2005

The purpose of this study is to make clear the indoor thermal environmental efficiency of indoor garden in apartment during winter. The questionnaire survey was carried out during the l0th${\sim}$20th of February 2004, respondents consisted of 215 residents living in a subject apartment estate. The field measurements of indoor thermal elements were carried out at A house with indoor garden and at B house without indoor garden. The measurements in two-subject houses were taken on simultaneously the 11th of February. As Results, the residents living in apartments with indoor garden show positive response on air moisture and satisfaction. The daily ranges of indoor temperature and globe temperature in the A house were narrower than the B house. The average relative humidity in the A house was higher and constant than the B house. Therefore, it was seemed that indoor environment during winter in the house with indoor garden maintained more constant or comfortable than the house without indoor garden by earning effect and humidity control effect of plants.

• 한국항만학회지
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• 제14권4호
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• pp.475-479
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• 2000

A possibility of the implementation of a quartz crystal sensor to the determination of chemical oxygen demand is examined by checking the electrochemical behavior of the sensor in a glucose solution. Since the surface of a quartz crystal has to be oxidized, a relatively active metal is coated on the surface of a usual 9 MHz AT-cut crystal. The electrochemical behavior is investigated by measuring the changes of current, resonant frequency and resonant resistance while a constant potential is applied. The crystal is installed in a specially designed container, and a quartz crystal analyzer is utilized to measure the frequency and resistance simultaneously. The variations of the measurements are examined at different concentrations of glucose solution, and a proper relation between the concentrations of glucose solution, and a proper relation between the concentration and the measurements is analyzed. As a result, it is found that a linear relation between the concentration of less than 900 ppm and the peak current when a constant potential of -180 mV (SSCE) is applied. The relation can be utilized for the determination of glucose concentration in sea water, and considering a direct relation between gluose concentration and chemical oxygen demand tells a possibility of the measurement of chemical oxygen demand using quartz crystal oscillators.

• Smart Structures and Systems
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• 제24권2호
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• pp.209-221
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• 2019

The classical Kalman filter (KF) provides a practical and efficient way for state estimation. It is, however, not applicable when the external excitations applied to the structures are unknown. Moreover, it is known the classical KF is only suitable for linear systems and can't handle the nonlinear cases. The aim of this paper is to extend the classical KF approach to circumvent the aforementioned limitations for the joint estimation of structural states and the unknown inputs. On the basis of the scheme of the classical KF, analytical recursive solution of an improved KF approach is derived and presented. A revised form of observation equation is obtained basing on a projection matrix. The structural states and the unknown inputs are then simultaneously estimated with limited measurements in linear or nonlinear systems. The efficiency and accuracy of the proposed approach is verified via a five-story shear building, a simply supported beam, and three sorts of nonlinear hysteretic structures. The shaking table tests of a five-story building structure are also employed for the validation of the robustness of the proposed approach. Numerical and experimental results show that the proposed approach can not only satisfactorily estimate structural states, but also identify unknown loadings with acceptable accuracy for both linear and nonlinear systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권7호
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• pp.2339-2355
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• 2021

In this paper, a joint probabilistic data association algorithm based on loss function (LJPDA) is proposed so that the computation load and accuracy of the multi-target tracking algorithm can be guaranteed simultaneously. Firstly, data association is divided in to three cases based on the relationship among validation gates and the number of measurements in the overlapping area for validation gates. Also the contribution coefficient is employed for evaluating the contribution of a measurement to a target, and the loss function, which reflects the cost of the new proposed data association algorithm, is defined. Moreover, the equation set of optimal contribution coefficient is given by minimizing the loss function, and the optimal contribution coefficient can be attained by using the Newton-Raphson method. In this way, the weighted value of each target can be achieved, and the data association among measurements and tracks can be realized. Finally, we compare performances of LJPDA proposed and joint probabilistic data association (JPDA) algorithm via numerical simulations, and much attention is paid on real-time performance and estimation error. Theoretical analysis and experimental results reveal that the LJPDA algorithm proposed exhibits small estimation error and low computation complexity.