• Journal of Advanced Marine Engineering and Technology
• /
• 제24권1호
• /
• pp.127-133
• /
• 2000

A numerical study of the flow of incompressible fluid in a polar cavity is presented. Irregular grids is proposed by applying the interior division principle to the variables on polar coordinate grid formation. Stability analysis and the pressure correction method of SOLA algorithms were discussed in detail on cylindrical coordinates. The results present that unsteady flow behavior appears over $Re=3{\times}10^4$ on polar cavities but nearly steady state at $Re=10^4$. Furthermore, with increasing Reynolds numbers, vortices behaviors indicate more complicated flow phenomena and more severe temporal fluctuation of total kinetic energy and time variation of velocity components at arbitrary pick-up points are detected in case of $Re=5{\times}10^4$.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1076-1079
• /
• 2003

The vector field histogram(VFH) uses a two-dimensional Cartesian histogram grid as a world model. The VFH method subsequently employs a two-stage data-reduction process in order to compute the desired control commands for the vehicle. In the first stage the histogram grid is reduced to a one dimensional polar histogram that is constructed around the robot's momentary location. Each sector in the polar histogram contains a value representing the polar obstacle density in that direction. In the second stage, the algorithm selects the most suitable sector from among all polar histogram sectors with a low polar obstacle density, and the steering of the robot is aligned with that direction. We applied this algorithm to our simulation program and tested..

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
• /
• pp.7-10
• /
• 2003

In this paper, we present a new echo kernel, which is a modification of polar echo kernel. to improve the detection performance and robustness against attacks. Polar echo kernel may take advantage of large detection margin from the polarity of inserted echo signal, but its poor frequency response in low frequency band degrades sound quality. To solve this problem, we applied bipolar echo pulses to the polar echo kernel. Using the proposed echo kernel the distributions of autocepstrum peaks fur data ‘0’ and ‘1’ are located more distant and improvement of detection performance is achieved. It also makes the low frequency band flat so that the timbre difference in the polar echo kernel can be removed to reproduce the imperceptible sound qualify. Informal listening tests as well as robustness test against attacks were performed to evaluate the proposed echo kernel. Experimental results demonstrated the superiority of the proposed echo kernel to both conventional unipolar and polar echo kernels

• Mycobiology
• /
• 제37권3호
• /
• pp.240-242
• /
• 2009

An improved procedure for preparing PCR cloning vectors was developed. This procedure includes the incorporation of adapters to create XcmI restriction enzyme sites in pBluescript II SK(+) vectors, digestion with XcmI followed by further digestion of the small fragment produced by XcmI digestion with additional enzymes, and purification with PCR purification kits. Using this procedure, PCR cloning vectors with high ligation efficiencies and low blue or false-positive colonies were obtained.

• Bulletin of the Korean Chemical Society
• /
• 제33권7호
• /
• pp.2411-2414
• /
• 2012

• 한국환경과학회지
• /
• 제12권9호
• /
• pp.943-948
• /
• 2003

Variation of the polar front in the East Sea is studied using temperature and dissolved oxygen data obtained from Japan Meteorological Agency from 1972 to 1999. Variation of the polar front in the East Sea has a close relation to the variation of the Tsushima Warm Current (TWC). When the TWC spreads widely in the East Sea, polar front moves northward. The spatial variation of the polar front is greater in the southwestern area of the East Sea and the northern area of Tsugaru Strait where the variation of the TWC's distribution area is greater than those in others of the East Sea. Hence, in the southeastern area of the East Sea, that is, between near Noto peninsula and Tsugaru Strait, the spatial variation of the polar front is not so wide as in the southwestern area because the flow of TWC is stable.

• 한국해양생명과학회지
• /
• 제7권2호
• /
• pp.74-85
• /
• 2022

Organisms constituting a large proportion of marine ecosystems, ranging from bacteria to fish, exhibit fluorescence and bioluminescence. A variety of marine organisms utilize these biochemically generated light sources for feeding, reproduction, communication, and defense. Since the discovery of green fluorescent protein and the luciferin-luciferase system more than a century ago, numerous studies have been conducted to characterize their function and regulatory mechanism. The unique properties of fluorescent and bioluminescent proteins offer great potential for their use in a broad range of applications. This short review briefly describes the functions and characteristics of fluorescent and bioluminescent proteins, in addition to summarizing the recent status of their applications.

• 한국군사과학기술학회지
• /
• 제27권4호
• /
• pp.485-494
• /
• 2024

In this paper, polar converting logic of bank-to-turn with skidding is provided for small size UAV. In general, original polar converting logic has problems of singularity, safety and flight data analysis when acceleration commands diverge at the end of terminal guidance. To solve those problems, new methodology of polar converting logic of bank-to-turn with skidding is presented. It can easily solve singularity problem, increase safety and provide intuition of data analysis. Simulation and flight results are presented to verify proposed polar converting logic for bank-to-turn with skidding method.

• 한국제4기학회지
• /
• 제21권2호
• /
• pp.64-67
• /
• 2007

• 한국항해항만학회지
• /
• 제38권1호
• /
• pp.59-64
• /
• 2014

지구온난화로 인해 극지방의 해빙속도가 빠르게 증가하고 있으며, 이러한 환경변화로 북극항로에 대한 관심은 북극해 주변국뿐만 아니라, 먼 이웃국가들에게까지 확산되고 있다. 과거 극지역을 항해하는 선박에 대한 설계 및 운용과 관련된 선급 규칙은 주로 북극해에 인접한 러시아, 노르웨이, 핀란드에 의해서 주로 개정되어 왔다. 그러나 국제해사기구(IMO)에서는 극지해역을 운항하는 선박에 대한 안전성을 확보하기 위해, 강제규정인 극지방운항선박 안전코드(Polar Code)를 제정하기로 결정하였으며, 현재 2014년에 개발을 완료할 예정이다. 본 논문은 이러한 극지방운항선박 안전코드의 제정 현황을 파악하고, 앞으로 극지방운항선박 안전코드의 제정을 위한 우리나라의 각 기관의 역할 및 시사점 대해 분석하고자 한다.