• 한국산림과학회지
• /
• 제80권2호
• /
• pp.246-254
• /
• 1991

동립효소(同立酵素) 분석(分析)에 의하여 경상북도(慶尙北道) 영일지역(迎日地域) 한 소나무 집단(集團)의 유전적(遺傳的) 구조(構造)를 산(山)의 남(南)쪽과 북(北)쪽의 소집단(小集團)으로 구분(區分)하여 연구(硏究)하였다. 동립효소(同立酵素) AAT, GDH 및 LAP등 에서 각각 5개, 1개 및 2개의 유전자좌(遺傳子座)가 발견(發見)되였으며 상세(詳細)히 분석(分析)한 6개의 유전자좌(遺傳子座)에는 평균(平均) 3.33개의 유전자(遺傳子)가 있음이 확인(確認)되었다. 6개 유전자좌(遺傳子座)의 average heterozygosity는 양친집단(兩親集團)의 경우(境遇) 0.19였고 차대집단(次代集團)의 경우(境遇)는 0.17이었다. 몇 몇 유전자좌(遺傳子座)에 있어서 남(南)쪽 북(北)쪽 소집단내(小集團內) 및 소집단간(小集團間)에 모계(母系)와 부계간(父系間) 유전자빈도(遺傳子頻度)의 유의차(有意差)가 있었고 남쪽 및 북쪽 소집단간(小集團間)에는 모계(母系) 유전자(遺傳子) 빈도(頻度)에 차이(差異)가 있었다. 이 결과(結果)로 보아 산(山)의 북쪽과 남쪽에 위치(位置)한 소나무 소집단(小集團)에 있어서 교배(交配)가 무작위(無作爲)로 일어나지 않았으며 소집단간(小集團間)에도 자유(自由)롭게 교배(交配)가 이루어지지 않고 있어 이들 소집단(小集團)들은 최소(最小)한 생식집단(生植集團)으로서 부분적(部分的)으로 서로 격리되고 있음이 발견(發見)되었다. 양친(兩親)과 차대집단(次代集團)의 몇몇 유전자형(遺傳子型)들은 Hardy-Weinberg 평형(平衡)을 이루지 못하고 있었다. 이 소나무 집단(集團)의 유전적(遺傳的) 구조(構造)로 보아 현재의 소나무 집단(集團)은 소수(少數)의 양친수(兩親樹)에 의해 형성(形成)된 것으로 생각된다.

• Computers and Concrete
• /
• 제12권2호
• /
• pp.131-149
• /
• 2013

Various types of reinforcement splicing methods have been developed and implemented in reinforced concrete construction projects for achieving the continuity of reinforcements. Due to the complicated reinforcement arrangements and the difficulties in securing bar spacing, the traditional lap splicing method, which has been widely used in reinforced concrete constructions, often shows low constructability and difficulties in quality control. Also, lap spliced regions are likely to be over-reinforced, which may not be desirable in seismic design. On the other hand, mechanical splicing methods can offer simple and clear arrangements of reinforcement. In order to utilize the couplers for the ribbed-deformed bars, however, additional screw processing at the ends of reinforcing bars is typically required, which often lead to performance degradations of reinforced concrete members due to the lack of workmanship in screw processing or in adjusting the length of reinforcing bars. On the contrary, the use of screw-ribbed reinforcements can easily solve these issues on the mechanical splicing methods, because it does not require the screw process on the bar. In this study, the mechanical coupler suitable for the screw-ribbed reinforcements has been developed, in which any gap between the reinforcements and sleeve device can be removed by grouting high-flow inorganic mortar. This study presents the uniaxial tension tests on the screw-ribbed reinforcement with the mechanical sleeve devices and the cyclic loading tests on RC columns with the developed coupler. The test results show that the mechanical sleeve connection developed in this study has an excellent splicing performance, and that it is applicable to reinforced concrete columns with a proper confinement by hoop reinforcement.

• 동남아시아연구
• /
• 제20권2호
• /
• pp.1-29
• /
• 2010

In 1835, quickly after the Cambodian king Ang Chan died, Vietnamese emperor Minh Mang started to proceed his ambition to grab the territory of Cambodia. As the first step, he stationed big forces led by Truong Minh Giang in Phnom Phen, and appointed the Ang Chan's second daughter, Mei, as the successor of her father but with the humble title of Chan Lap Quan Chu, or the Prefecture sovereign of Cambodia. This article discusses the ways how the Vietnamese leaders manipulated the status of the Cambodian queen with each step of protection, assimilation, and finally a rupture. The author seeks for Vietnamese own theory of annexation in the process. In doing so, the author claims that Vietnamese tough policy of annexation was closely interwoven with the unequal relationship between the Vietnamese emperors and the Cambodian queen, i. e. men and woman. The first chapter discusses how and why the second daughter was chosen, and what in reality the status of the queen was under the protection of Vietnamese general Truong Minh Giang. Second chapter shows how much Mei was bullied by the Vietnamese. She was kidnapped to Vietnam, and was even regarded by the Cambodian people that she became the 'lover' or the 'concubine' of the general Truong Minh Giang. Third chapter deals with Vietnam's retreat forced by the Cambodian resistance together with the Thai intervention, and discusses how much Vietnam tried to maintain its authority over Cambodia through the queen Mei. Cambodia, in the 19th century, was a experimental place for the 'mission of civilization' from the side of Vietnam. Mei was a main character in this period from the beginning to the end. The conclusion of this article stresses that the desire of Vietnam ('civilized') to assimilate Cambodia ('barbarious') was strengthened by the psychology of the male master (Vietnam) to domesticate the female subject (Cambodia). The relationship between Vietnam and Cambodia was not only political but also gender oriented. In this epic, the existence of the queen Mei should be regarded as an important key to understanding of the Vietnamese theory for the annexation of Cambodia.

• 한국지진공학회논문집
• /
• 제10권3호
• /
• pp.47-55
• /
• 2006

본 연구는 도로교의 교각으로 널리 사용되고 있는 2주형 철근 콘크리트 교각의 내진성능과 보강방안을 실험적으로 수행하였다. 실험체는 지름 400mm, 높이 2,000mm인 2주형 원형교각 10기를 제작하였으며, 하중은 $0.1f_{ck}A_g$ 크기의 축방향하중하에서 교축방향과 교축직각방향의 이축 횡방향하중을 교번 반복재하하였다. 실험변수는 심부구속철근비, 주하중방향, 주철근 겹침이음 그리고 보강방안을 선택하였다. 주철근 겹침이음이 있는 교각에 대한 보강방안으로 steel band, steel jacket, 그리고 prestress 강선을 이용하였다. 실험 결과 주하중방향이 교축직각인 실험체가 소성힌지구간이 교각의 상 하부 양측에 발생하면서 주하중 방향이 교축방향인 실험체보다 연성 능력이 우수한 것으로 나타났다. 프리스트레스 강선으로 보강한 실험체는 과보강으로 인한 소성힌지구간의 이동으로 연성도 저하가 나타났으나, steel jacket 및 steel band로 보강한 실험체는 모두 요구연성도를 만족하는 것으로 나타났다. 특히, steel band에 의한 보강방안은 시공성 등을 감안하여 바람직한 철근 콘크리트 교각의 내진 보강방안으로 고려될 수 있다.

• 한국건설순환자원학회논문집
• /
• 제9권3호
• /
• pp.338-347
• /
• 2021

본 논문은 층간 보강재를 보강한 3D 프린팅 콘크리트의 부착강도를 평가하기 위해 수행되었다. 겹침이음 길이에 따라 두 종류의 층간 보강 방법을 고려하였다. 첫 번째 방법은 층간 보강재의 겹침이음을 하지 않았으며, 두 번째 방법은 40mm의 겹침이음을 고려하였다. 또한, 기건양생 조건과 수중양생 조건의 서로 다른 양생 조건을 고려하였다. 실험 변수를 고려하여 3D 프린팅 콘크리트 시편의 압축강도, 쪼갬인장강도 및 휨인장강도를 세가지 하중 방향에서 측정하였다. 압축강도, 쪼갬인장강도 및 휨인장 강도는 하중방향에 영향을 받았다. 특히 3D 프린팅으로 제작한 콘크리트 시편의 층간 부착면에 인장력이 작용하면 쪼갬인장강도 및 휨인장강도가 크게 감소하였다. 그러나 층간 보강재가 보강된 층의 종방향으로 하중이 가해질 때, 프린팅된 시편의 휨인장강도 또는 부착강도는 크게 증가하였다. 또한 기건양생 조건의 휨인장강도 또는 부착강도는 감소하였으며, 기건 양생 조건에 의해 더 많은 공극의 형성을 유발하여 하중에 더 취약해지는 것으로 나타났다.

• Advances in aircraft and spacecraft science
• /
• 제11권1호
• /
• pp.83-103
• /
• 2024

Adhesive bonding is currently widely used in many industrial fields, particularly in the aeronautics sector. Despite its advantages over mechanical joints such as riveting and welding, adhesive bonding is mostly used for secondary structures due to its low peel strength; especially if it is simultaneously exposed to temperature and humidity; and often presence of bonding defects. In fact, during joint preparation, several types of defects can be introduced into the adhesive layer such as air bubbles, cavities, or cracks, which induce stress concentrations potentially leading to premature failure. Indeed, the presence of defects in the adhesive joint has a significant effect on adhesive stresses, which emphasizes the need for a good surface treatment. The research in this field is aimed at minimizing the stresses in the adhesive joint at its free edges by geometric modifications of the ovelapping part and/or by changing the nature of the substrates. In this study, the finite element method is used to describe the mechanical behavior of bonded joints. Thus, a three-dimensional model is made to analyze the effect of defects in the adhesive joint at areas of high stress concentrations. The analysis consists of estimating the different stresses in an adhesive joint between two 2024-T3 aluminum plates. Two types of single lap joints(SLJ) were analyzed: a standard SLJ and another modified by removing 0.2 mm of material from the thickness of one plate along the overlap length, taking into account several factors such as the applied load, shape, size and position of the defect. The obtained results clearly show that the presence of a bonding defect significantly affects stresses in the adhesive joint, which become important if the joint is subjected to a higher applied load. On the other hand, the geometric modification made to the plate considerably reduces the various stresses in the adhesive joint even in the presence of a bonding defect.

• 한국환경과학회지
• /
• 제15권8호
• /
• pp.745-757
• /
• 2006

We focus on the improvement of accuracy of sea surface wind over complex coastal area doling the warm season. Local Analysis Prediction System (LAPS) was used to improve the initial values in Mesoscale Meteorological model (MM5). During the clear summer days with weak wind speed, sea surface wind simulated with LAPS was compared with the case without LAPS. The results of modeling with LAPS has a good agreement mesoscale circulation such as mountain and valley winds on land and in case of modeling without LAPS, wind speed overestimated over the sea in the daytime. And the results of simulation with LAPS indicated similar wind speed values to observational data over the sea under influence of data assimilation using BUOY, QuikSCAT, and AMEBAS. The present study suggests that MM5 modelling with LAPS showed more improved results than that of without LAPS to simulate sea surface wind over the complex coastal area.

• ETRI Journal
• /
• 제42권2호
• /
• pp.258-271
• /
• 2020

A correlation exists between luminance samples and chrominance samples of a color image. It is beneficial to exploit such interchannel redundancy for color image compression. We propose an algorithm that predicts chrominance components Cb and Cr from the luminance component Y. The prediction model is trained by supervised learning with Laplacian-regularized least squares to minimize the total prediction error. Kernel principal component analysis mapping, which reduces computational complexity, is implemented on the same point set at both the encoder and decoder to ensure that predictions are identical at both the ends without signaling extra location information. In addition, chrominance subsampling and entropy coding for model parameters are adopted to further reduce the bit rate. Finally, luminance information and model parameters are stored for image reconstruction. Experimental results show the performance superiority of the proposed algorithm over its predecessor and JPEG, and even over JPEG-XR. The compensation version with the chrominance difference of the proposed algorithm performs close to and even better than JPEG2000 in some cases.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1997년도 전력전자학술대회 논문집
• /
• pp.45-48
• /
• 1997

The low frequency pulsed MIG welding process of new current waveform control to switch over unit pulse conditions (pulse current, pulse duration) in the fixed cycle was developed and its effect were investigated for aluminium and its alloy. By using this new welding process, the bead appearance having clear ripple pattern, such as TIG welding bead can be obtained and the gap tolerance of lap and butt welding joint can be expanded.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.261-264
• /
• 1993

To reconstruct the real 3-D shape from the 3-D measurement data from the multiple directions, the rconstruction of the object on the basis of the mosaic processing of the 3-D measurement data are proposed. In this method, to conduct the reconstruction, the connection points have to be identified among the over-lap area between adjacent 3-D data. In this study, the simple image matching method is adopted for the identification of connection points, and this method is verified from numerical experiments.