• Journal of Ecology and Environment
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• v.29 no.6
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• pp.489-494
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• 2006

For the ecosystem conservation and the effective management of naturalized plant species on 261 uninhabited islands distributed in southern and western sea in Korea, we tested the interrelationship between the pattern of distribution and dispersal of the naturalized plant species and the factors of geographical environment of uninhabited islands such as island area, distance from mainland, latitude, longitude, human impacts and habitat diversity. Out of 261 uninhabited islands surveyed, 106 species of the naturalized plants occurred on 229 (87.7%) islands. The naturalized plant species per island averaged 4.6 (SD=4.07) species, and plant species number were higher in southern group (87 species) than in western group (64 species) of islands. Plant species occurred on more than 100 islands were three species : Rumex crispus L. (153 islands), Erigeron annuus Pers. (130 islands), and Conyza canadensis (L.) Cronquist (121 islands), the highest grade '5' of 'degree of naturalization'. The occurrence frequency of 106 naturalized plant species was significantly correlated with island area, distance to mainland, strength of human impacts, and latitude and longitude. Correlation coefficient (r=-0.330) between occurrence frequency and distance from mainland was higher than between occurrence frequency and island area (r=-0.182). The result of path analysis confirmed that plant species number was significantly affected by island area p=0.336) and distance from mainland (p=-0.490), but in this analysis the effect of human impacts on plant species number was very weak (p=0.003). On the basis of these results, strategies on the conservation of ecosystem and the management of naturalized plant species in the uninhabited islands of Korea were discussed.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.5
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• pp.96-103
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• 2009

This paper describes a humanoid robot's intelligent foot with two six-axis force/moment sensors. The developed humanoid robots didn't get the intelligent feet for walking on uneven surface safely. In order to walk on uneven surface safely, the robot should measure the reaction forces and moments applied on the sales of the feet, and they should be controlled with the measured the forces and moments. In this paper, an intelligent foot for a humanoid robot was developed. First, the body of foot was designed to be rotated the toe and the heel to all directions, second, the six-axis force/moment sensors were manufactured, third, the high-speed controller was manufactured using DSP(digital signal processor), fourth, the humanoid robot's intelligent foot was manufactured using the body of foot, two six-axis force/moment sensors and the high-speed controller, finally, the characteristic test of the intelligent foot was carried out. It is thought that the foot could be used for a humanoid robot.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.12
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• pp.78-84
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• 2009

When external force is applied to humanoid robot's head, humanoid robot's neck is rotated to prevent the damage of it. So, robot's neck have to perceive forces (Fx of x-direction, Fy of y-direction and Fz of z-direction) and moments (Mx of x-direction, My of y-direction and Mz of z-direction) using the attached 6-axis force/moment sensor. Thus, in this paper, 6-axis force/moment sensor was developed to sense the forces and moments applied to robot's head. The structure of 6-axis force/moment sensor was modeled newly, and it was designed using FEM software (ANSYS) and manufactured by attaching straingages on the sensing element, finally, the characteristic test of the sensor was carried out. As a result, it is confirmed that interference error is less than 3%. And, it is thought that the sensor can be used to measure the forces and the moments for humanoid robot's head.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.48-55
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• 1992

자연초원(natural grassland)은 연간 강수량이 $250\sim1000mm$, 기온이 $0\sim26^{\circ}C$인 지역에서 형성되는 기후극상의 식생으로써 초본식물, 특히 벼과식물이 우점되어 있다. 이 자연초원은 세계에 널리 분포되어 있는데 지역에 따라 온대초원 열대초원, steppe, prairie, pampa등으로, 식물의 초고에 따라 장초형 초원 단초형초원으로 분류한다. 한국에는 연간 강수량이 많고 연평균기온이 높아서 기후 극상의 자연초원은 성립되지 못하고 식생천이의 도중상으로 소규모의 초본식물군락이 나타난다. 이들은 주로 방치된 경작지나 경작지주변의 인간간섭이 많은곳, 해수나 강물의 영향으로 나무가 생장할 수 없는 곳에 식생천이의 도중상으로 나타나거나, 산림이 산불이나 벌목으로 파괴된 곳에서 제2차천이의 과정으로 초본식물군락이 출현하는데 이것을 야초지(native grassland)라고 한다. 특히 야초지에 가축을 사육할 목적으로 목초를 재배하여 이용할 때는 초지라고 한다. 한국의 야초지식생을 구성하는 주요 우점초종은 억새, 새, 솔새, 잔디, 갈대, 쑥 등이며 건조하고 기온이 높은 여름에는 C-4형 식물이, 수분이 많고 서늘한 봄과 가을에는 C-3형 식물이 높은 생산성을 나타낸다. 야초지는 지표면을 피복하여 바람이나 빗물에 의한 토양침식을 방지할 뿐만아니라 초식동물의 먹이를 생산하고 자연경관을 아름답게 가꾸어 주는 중요한 역활을 하고 있으나 공장부지 주택지 농업용지등으로 개발되어 없어지고 관리가 이루어지지 않아 황폐화 되고 있다. 야초지를 효과적으로 보전하고 이용하기 위해서는 생장이 빠르고 생산성이 높은 우수한 목초를 재배하는 것이 바람직한데 그 방법으로는 겉뿌림초지조성법, 제경법, 시비법이 이용된다.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.181-187
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• 2006

In recent years the number of patients waiting for organ transplantation has greatly outpaced the supply of human organs available, which leads to a renewed interest in pig-to-human xenotransplantation as an alternative. However, one of the biggest barriers in the xenotransplantation is presence of porcine endogenous retroviruses(PERV) that can infect human cells. In this study, to present a possible solution for this problem we tried to inhibit expression of PERVs using shRNAs(short hairpin RNA) at the level of RNA synthesis and virus release. The shRNA targeting the sequence of PERV A, B type was cloned into pSIREN-RetroQ vector under the control of polymerase-III U6-RNA gene promoter. Quantitative real-time PCR was performed to detect my alterations in mRNA production of PERV A, B targeted by the shRNA in each done. Depending on the target sequence of the shRNA, the transcription of PERV was decreased to as much as 4% and the number of progeny viruses was reduced to less than 1/200,000. Transgenic pigs producing such shRNAs may result in a highly reduced PERV expression in cells and organs, which is a prerequisite for safe xenotransplantations.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.27-36
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• 2007

This paper describes the development of 6-axis ankle force/moment sensor for the intelligent feet of a humanoid robot. When the robot walks on uneven terrain, the feet should perceive the applied forces Fx, Fy, Fz and moments Mx, My, Mz from the attached 6-axis force/moment sensor on their ankles. Papers have already been published have some disadvantages in the size of the sensor, the rated output and so on. The rated output of each component sensor (6-axis ankle force/moment sensor) is very important to design the 6-axis force/moment sensor for precision measurement. Therefore, each sensor should be designed to get the similar rated output under each rated load. Also, the size of the sensor is very important for mounting to robot's feet. Therefore, the diameter should be below 100 mm and the height should be below 40mm. In this paper, first, the structure of a 6-axis ankle force/moment sensor was modeled for a humanoid robot's feet newly, Second, the equations to predict the strains on the sensing elements was derived, third, the size of the sensing elements was designed by using the equations, then, the sensor was fabricated by attaching straingages on the sensing elements, finally, the characteristic test of the developed sensor was carried out. The rated outputs from the derived equations agree well with the results from the experiments. The interference error of the sensor is less than 2.94%.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.263-269
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• 2015

Digital watermarking is imperceptible and statistically undetectable information embeds into digital data. Most information in digital audio watermarking schemes have used binary random sequences. The embedded binary random sequence distorts and modifies the original data while it plays a vital role in security. In this paper, a binary random sequence to improve imperceptibility in perceptual region of the human auditory system is proposed. The basic idea of this work is a modification of a binary random sequence according to the frequency analysis of adjacent binary digits that have different signs in the sequence. The canonical signed digit code (CSDC) is also applied to modify a general binary random sequence and the pair-matching function between original and its modified version. In our experiment, frequency characteristics of the proposed binary random sequence was evaluated and analyzed by Bark scale representation of frequency and frequency gains.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.175-179
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• 2005

본 연구는 2002년 10월부터 2003년 9월까지 경상북도 봉화군 운곡천을 대상으로 수달의 배설물 및 배설지 등의 흔적조사를 통해 얻은 GPS좌표를 중심으로 하여 수치지도 및 현장조사에서 얻은 정보를 Arc/view를 이용해 수달의 최적 서식지분석에 이용하였다. 분석결과 수달의 서식지 이용에는 먹이자원인 어류의 종다양도와 풍부도가 깊은 연관을 맺고 있으며 식생 등의 서식환경이 밀접한 연관을 맺고 있음을 확인하였다 또한, 밀집된 주거지 등 인간의 간섭은 수달의 서식지 이용에 교란요인으로 작용한다는 것을 알 수 있었다. 본 연구는 수달의 보전 및 관리를 위한 적합 서식지를 선정하기 위해 GIS기법의 활용에 대한 적용 가능성을 평가하였다.

• Information and Communications Magazine
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• v.27 no.11
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• pp.36-43
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• 2010

현재 통신시장은 과거보다 치열한 무한경쟁시대에 돌입하고 있다. 스마트 폰의 등장으로 통신사와 비통신사와의 경계는 무너졌고, 사용자는 더 이상 획일화된 통신서비스를 원하지 않는다. 이러한 현상은 사업 분야의 다양성을 유도하게 되었고 사업자들은 사활을 걸고 신규 서비스 창출을 추진 중에 있다. 사물지능통신(M2M)은 이러한 통신 산업의 구조 변화와 맞물려 집중적으로 관심을 받고 있다. 사람이 중심이 아닌 사물이 중심이 되는 통신, 인간의 간섭이 더 이상 필요 없고, 적시적소에 서비스가 찾아가는 통신서비스 이것이 사물지능통신(M2M)이다. 이미 해외에서는 관련 산업의 중요성을 인식하고 이에 대한 다양한 관련서비스들이 추진하고 있다. 그러나 국내의 경우에는 중요성은 인식되는 반면 사업화 단계에 있어서는 아직 초기단계 있다. 본 논문에서는 이러한 점을 고려하여 현재까지 사물지능통신(M2M)에 대한 국내외 현황을 분석하고 이에 대한 발전 전망을 고찰을 한다. 이를 위해서 국내외 관련정책 현황 및 사업화 현황, 그리고 표준화 현황을 분석하고 이를 통해 사물지능통신(M2M)의 미래를 전망을 전망한다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.231-236
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• 1999

외부의 자극에 따른 인간 감성 변화의 실체를 파악하고자 심리학, 생리학, 의공학 등의 분야에서 많은 연구가 이루어져 왔다. 본 논문은 fMRI의 기본 원리와 지금까지 저자들의 fMRI 연구 내용을 중심으로 감성 변화의 측정에 이용 또는 응용 가능성이 있는 실험 결과들에 대해서 서술하고자 한다. 먼저 자극강도에 따른 해당피질에서의 활성화 영역의 분석을 통해 외부 자극과 반응 영역간의 정량적인 측정이 가능하다는 것을 보였다. 둘째로 시간축 신호의 해석을 통해 감성 변화의 추이를 관찰할 수 있다는 것을 보였다. 마지막으로 간섭요인 (소음)이 뇌기능에 미치는 영향에 대한 분석을 통해 감성의 변화가 이의의 뇌기능 수행에 미치는 영향을 유추해 보았다.