• 한국군사과학기술학회지
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• 제23권1호
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• pp.52-58
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• 2020

In this paper, a 2-dimensional phase comparison direction finding receiver was designed and fabricated. For 2-D comparison direction finding, direction finding formulas were derived from a uniformly arranged of four antennas. Based on this, a direction finding receiver was designed using Matlab simulink, and the direction finding receiver was fabricated. To analyze the performance of the designed direction finding receiver, the injection direction finding accuracy and simulation results were compared. As a result of the test, the fabricated direction finding receiver showed a maximum of 3° RMS precision, and the result of both tests showed similar trends. Also, it was confirmed that the direction finding accuracy of elevation angle is about 2.7 times better than azimuth angle, and both models performed well within 0.7° RMS at the boresight.

• 연구윤리
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• 제3권1호
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• pp.17-21
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• 2022

Purpose: Research ethics has social implications beyond the issues of personal morality and research integrity. In recent years, research ethics has become a more controversial topic in society. In this study, the concept of the university research ethics curriculum is defined, the current status of the research ethics curriculum is analyzed, and the direction of the university research ethics curriculum development direction is discussed. Research design, data and methodology: The concept of university research ethics education and the current status of research ethics education were examined, and the development direction of the university research ethics curriculum was explored based on the framework . Results: field education to secure university research ethics is still insufficient. In other words, only 12 universities for undergraduate programs and 37 universities for graduate programs included research ethics in their regular curriculum. Conclusions: The occurrence of research misconduct is mainly caused by not recognizing the error or not taking it seriously. In particular, university research misconduct results from a lack of understanding of research ethics, poor research education, a performance-oriented academic climate, and the absence of an institutional system for establishing research ethics.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.911-912
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• 2004

1. Cathodic hydrogen charging considerably reduced the tensile ductility of ODS steels and a 9Cr-2W RMS. The hydrogen embrittlement of ODS steels was strongly affected by specimen sampling orientation, showing significant embrittlement in the T-direction. This comes from the microstructural anisotropy caused by elongated grains of ODS steels in L-direction. 2. The ODS steels contained a higher concentration of hydrogen than 9Cr-2W RMS at the same cathodic charging condition, and the critical hydrogen concentration required to transition from ductile to brittle fracture was in the range of $10{\sim}12$ wppm, which approximately 10 times larger than that of a 9Cr-2W martensitic steel. 3. The ODS steels showed a typical ductile to brittle transition behavior and it strongly depended on the specimen sampling direction, namely L- and T-direction. In T-direction, the SP-DBTT was about 170 L, irrespective of the ODS materials, and L-direction showed a lower SP-DBTT than that of T-direction.

• International Journal of CAD/CAM
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• 제3권1_2호
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• pp.77-83
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• 2003

We propose two algorithms to generate (1) polygonal meshes and (2) developable surface patches far generalized cylinders defined by contours of discrete curves. To solve the contour blending problem of generalized cylinder, the presented algorithms have adopted the algorithm and related properties of LIDM (linear interpolation by direction map) that interpolate geometric shapes based on direction map merging and group scaling operations. Proposed methods are fast to compute and easy to implement.

• 대한조선학회논문집
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• 제50권5호
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• pp.307-313
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• 2013

This paper presents a simulation for passenger ship evacuation considering determination of evacuating direction based on walking direction potential function. In order to determine walking direction of a passenger, his/her position in two dimensional plane was adopted as a design variable, and fixed boundaries such as walls and obstacles were adopted as constraints. To solve this optimum problem, a walking direction potential function was adopted as an objective function. This potential function was configured as a kind of penalty function and it contained two components. One is a potential function concerned with the distance to the destination, and other is a potential function based on the effect of walls and obstacles. To determine evacuating direction, this problem was solved by minimizing the walking direction potential function every unit time during the simulation. The crowd behavior of the passenger consisted of the flock behavior, a form of collective behavior of a large number of interacting passengers with a common group. With the proposed algorithm, the test problems in International Maritime Organization, Maritime Safety Committee/Circulation 1238(IMO MSC/Circ.1238) were implemented and the direction of passengers and total evacuation time was analyzed.

• 로봇학회논문지
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• 제9권4호
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• pp.206-215
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• 2014

Acoustic signal is crucial for the autonomous navigation of underwater vehicles. For this purpose, this paper presents a method of acoustic source localization. The proposed method is based on the probabilistic estimation of time delay of acoustic signals received by two hydrophones. Using Bayesian update process, the proposed method can provide reliable estimation of direction angle of the acoustic source. The acquired direction information is used to estimate the location of the acoustic source. By accumulating direction information from various vehicle locations, the acoustic source localization is achieved using extended Kalman filter. The proposed method can provide a reliable estimation of the direction and location of the acoustic source, even under for a noisy acoustic signal. Experimental results demonstrate the performance of the proposed acoustic source localization method in a real sea environment.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 초전도 자성체 연구회
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• pp.50-54
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• 2003

The output characteristics of thin film NiO/NiFe bilayered magnetoresistive device have been measured as a function of the direction of external magnetic field. Each layer was fabricated by rf magnetron sputtering method, and especially, the under layer, NiO, was fabricated under the in-situmagnetic field of about 1000Oe. The magnetoresistive devices were designed with the angle of 45degree between the direction of current of the device pattern and the induces magnetic field in the NiO film layer. The output of the devices had a good linearity when the devices were placed on the external magnetic field perpendicular to induced field direction and also 45 degree with the currenr path direction.

• 한국군사과학기술학회지
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• 제18권4호
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• pp.469-477
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• 2015

In this study, the characteristics of main wind direction, vertical temperature and wind speed profile near the Moseulpo airfield for HALE UAV(High Altitude Long Endurance Unmaned Aerial Vehicle) is investigated. The results are summarized as follows, main wind direction is governed by air mass according to season and local wind such as land-sea breeze. The directions of landing and take-off of HALE UAV will be selected as the south-east direction in June ~ August, north-west direction in October ~ March, and south-east direction at daytime in April ~ May, September. Annual variation of temperature at 100 hPa showed that temperature in summer season is lower than winter season. On the other hands, wind speed at 250 hPa in winter season is higher than summer season. The threshold values of temperature and wind speed for HALE UAV flight are $-75^{\circ}C$ and $90ms^{-1}$, which were determined by 5 % frequency value($1.96{\sigma}$), respectively.

• Carbon letters
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• 제1권2호
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• pp.76-81
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• 2000

Physical properties of artificial graphite electrodes were evaluated along three different directions; circumferential (X), radial (Y), and axial (Z) directions. Four kinds of commercial electrode products were used in this study for the evaluation; pole (AP) and nipple (AN) of manufacturer A, pole (BP) and nipple (BN) of manufacturer B. The mechanical, electrical, and thermal properties in X and Y directions were very similar to each other. In Z direction, however, the mechanical properties, including flexural strength and compressive strength, were higher, and electric resistance and thermal expansion were much lower than those in the other directions. The microstructures observed by optical microscope and scanning electron microscope revealed that the differences in properties by the measuring direction were caused by the preferential alignment of needle cokes along the Z direction. When comparing the properties of the electrode samples in the same direction, the mechanical properties mainly depended on the bulk density or porosity of the samples as well as preferential alignment of needle cokes.

• 교육녹색환경연구
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• 제8권1호
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• pp.34-46
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• 2009

The purpose of this study was to analyze the school location decision direction for land use planning of public land development. And this research proposed the school location decision direction for urban amenity. So this research present the implication on urban planning and design for architecture, park-school complex. This study perform the relationship with land use planning out side environment of school land. This research proved the fact that the school land relationship with the park, the other school land etc. And this result will be used in decision-making-process of land use planning, public land development construction, urban design and city policy.