• 반도체디스플레이기술학회지
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• 제21권4호
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• pp.99-105
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• 2022

Public attention to the indoor environment of underground subway stations, which is a representative multi-use facility, has been increasing along with the increase in indoor activities. In underground stations, fine iron oxide, which affects the health of users, is generated because of the friction between wheels and rails. Among particulate pollutant reduction technologies, plants have been considered as a non-chemical air purification method, and their effects in reducing certain chemical species have been identified in previous studies. The present study aimed to derive the total quantitative and qualitative reduction effects of a bio-filter system comprising air purifying plants, installed in an underground subway station. The experiment proceeded in two ways. First, PM(particulate matter) reduction effect by vegetation biofilter was monitored with the IAQ(indoor air quality) station. In addition, chemical speciation analysis conducted on the samples collected from the experimental and control areas where plants and irrigation using SEM-EDS(scanning electron microscopy-energy dispersive X-ray spectroscopy). This study confirmed the effect of the vegetation bio-filter system in reducing the accumulation of particulate pollutants and transition and other metals that are harmful to the human body.

• 한국해양공학회지
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• 제37권1호
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• pp.20-30
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• 2023

Modeling a nonlinear ocean wave is one of the primary concerns in ocean engineering and naval architecture to perform an accurate numerical study of wave-structure interactions. The high-order spectral (HOS) method, which can simulate nonlinear waves accurately and efficiently, was investigated to see its capability for nonlinear wave generation. An open-source (distributed under the terms of GPLv3) project named "HOS-ocean" was used in the present study. A parametric study on the "HOS-ocean" was performed with three-hour simulations of long-crested ocean waves. The considered sea conditions ranged from sea state 3 to sea state 7. One hundred simulations with fixed computational parameters but different random seeds were conducted to obtain representative results. The influences of HOS computational parameters were investigated using spectral analysis and the distribution of wave crests. The probability distributions of the wave crest were compared with the Rayleigh (first-order), Forristall (second-order), and Huang (empirical formula) distributions. The results verified that the HOS method could simulate the nonlinearity of ocean waves. A set of HOS computational parameters was suggested for the long-crested irregular wave simulation in sea states 3 to 7.

• 한국환경생태학회지
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• 제18권2호
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• pp.107-123
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• 2004

백두대간 덕유산지역 일대에 분포하는 식물상을 조사한 결과 91과 243속 353종 53변종 5품종 총 411종류가 확인되었다. 개비자나무, 생강나무, 대팻집나무 및 노각나무 등이 나타나 남부아구로 볼 수 있으나 거제수나무, 사스래나무, 처녀치마 및 금강애기나리 등 중부아구 식물도 확인되었으며, 해발 1,000m 이상인 곳에는 고산식물이 많이 분포하였다. 산림청이 지정한 희귀 및 멸종위기종은 솔나리와 산작약, 그리고 구상나무, 금강애기나리, 말나리, 뻐꾹나리, 누른종덩굴, 등대시호, 흰참꽃 및 꽃창포 등으로 총 10종이 확인되었다. 환경부지정 보호 야생 동ㆍ식물에 포함되어 있는 종은 솔나리 1종이 확인되었다. 한국특산식물종은 개비자나무, 구상나무, 일월비비추, 죽대, 뻐꾹나리 등 12과 21속 20종 1품종 1변종으로 총 22종류가 확인되었다.

• 한국전통조경학회지
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• 제38권3호
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• pp.35-49
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• 2020

본 연구는 경주시 내 황성공원에 분포하는 관속식물상을 조사·분석하여 도시림의 생태계 관리 및 보전을 위한 기초 자료 제공에 목적이 있다. 2018년 4월부터 2020년 5월까지 관속식물상을 조사한 결과는 총 78과 222속 296종 5아종 18변종 6품종 4잡종 9재배품종 등 338분류군이며, 식재종 110분류군, 자생종 235분류군이 확인되었다. 대표적인 식재종은 맥문동이었다. 희귀식물은 7분류군, 한국특산식물은 5분류군으로 나타났다. 식물구계학적 특정식물은 총 24분류군으로, V등급은 1분류군, IV등급은 4분류군, III등급은 7분류군, II등급은 4분류군, I등급은 8분류군이었다. 귀화식물은 57분류군, 생태계교란식물은 6분류군으로 나타났다. 특히 이팝나무는 우리나라 전통 조경수목을 대표하며, 생태적 가치가 높다. 따라서 이팝나무의 노거수는 개체별로 번호를 부여하여 관리를 해야 할 것이다. 생태계교란식물은 주기적인 방제와 함께 시민단체와 연계하여 작업할 수 있는 프로그램 개발이 필요할 것이다.

• ALGAE
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• 제27권3호
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• pp.189-196
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• 2012

Twelve morphological characters and the biochemical composition of Undaria pinnatifida f. distans sporophytes growing on the rocky shores of Jindo and Wando and on cultivation ropes in Kijang were measured to determine whether each population could be characterized by morphological features and biochemical composition. The goal of this study was to compare phenotypic variations between populations as they relate to environmental conditions. The sporophytes of the Kijang population were two times longer and 19 times heavier than those at Jindo. Sporophylls of the Jindo U. pinnatifida population were significantly smaller in length, width, frill number, and weight than those at Wando and Kijang. Kijang Undaria plants showed the highest contents of total protein, crude fiber, total amino acids, the amount of essential amino acids, the proportion of total unsaturated fatty acids, and eicosapentaenoic acid. However, the Jindo population showed the greatest content of carbohydrates, lipids, and minerals (Zn and Ca) of the three U. pinnatifida populations. In particular, Zn content of Jindo plants was 30 times greater than that of Kijang plants. Thus, the proximate composition, mineral composition, amino acids, and fatty acids of Undaria pinnatifida plants were distinguishable among the three representative Undaria populations evaluated. These results suggest that morphological and biochemical differences of the three U. pinnatifida populations can be attributed to differences in environmental conditions of their habitats.

• 한국환경복원기술학회지
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• 제14권2호
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• pp.47-57
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• 2011

This study monitored forest plant species vulnerable to climate change in Jiri Mountain, one of Korea's representative alpine regions, in order to securely preserve plant genetic resources susceptible to climate change and to utilize the results as basic data for bioclimatology prediction and management on a long-term basis. A majority of indicator plants tended to blossom one week to one month later in 2010 than in 2009. As with the blooming dates, the falling dates of blossoms became later in most species, with the exception for Weigela florida and Oplopanax elatus. Leaf bursting as well fell on later dates in a majority of species excluding Carpinus laxiflora and Cupressus sempervirens, displaying the most obvious differences among the data of analysis of the 2009-2010 physiological cycle changes. It is believed that was due to the fact that temperatures in February, March and April, which affect plants' blossoming and leaf bursting, were lower in 2010 than in 2009 and that cold temperatures in the winter lasted for a longer period in 2010 than in 2009. The dates of leaves being changed to red were similar in 2009 and 2010 by being or later or earlier by several weeks in 2010 than in 2009 without any regularity. Most species' leaves began to fall at similar dates in 2009 and 2010 or at later dates by one to two weeks in 2010 than in 2009. The temperature differences in late 2009 and late 2010 were not so large, resulting in similar dates of falling leaves, and gaps in several indicator plants' physiological cycles without any regularity can be attributed to each individual plant's physiological and environmental characteristics.

• 한국지능시스템학회논문지
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• 제7권3호
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• pp.21-33
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• 1997

본 논문에서는 바람직한 제어 방향의 학습을 통한 퍼지 제어기의 새로운 자기 구성 방법을 제안한다. 기울기 강하법에 기반하여 특성을 모르는 동적 플랜트에 대한 퍼지 제어기를 자기 구성할 때 풀어야할 문제중 하나는 오차를 줄이도록 하는 바람직한 제어입력의 변화방향을 알아내는 것이다. 이 문제를 해결하기 위한 방법으로서, 제어입력에 따른 오차의 변화 방향에 대한 대표 값을 분할된 상태영역에 할당하고, 반복적인 시행을 통해 강화 학습된 이 대표값을 이용하여 퍼지 제어 규칙을 학습하는 방법을 제안하였다. 제안된 자기구성 퍼지제어기는 간단한 구조를 가질 뿐 아니라 설계하기도 쉬운 장점을 갖는다. 제안된 방법의 타당성은 역진자 시스템에 대한 모의 실험을 통하여 검증하였다.

• 대한기계학회논문집A
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• 제29권10호
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• pp.1392-1398
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• 2005

API 581 guideline provides a methodology for calculating the risks of equipments in refinery or petrochemical plant. However, especially in part of the consequence of failure, there is a major limitation of its application to the petrochemical plant directly since only a representative material is considered in calculating the risk while the equipment is composed of numerous materials. The objectives of this paper are to propose an enhanced risk-based inspection (RBI) technique to resolve shortcomings inclusive of the above issue and to assess the risks of typical petrochemical equipments. In this respect, a program incorporating material database was developed to fully incorporate the characteristics of different materials. The proposed RBI program consists of qualitative, semi-quantitative and quantitative risk evaluation modules in which toxic materials as well as representative materials were selected automatically for comparison to those in the current guideline. It has been applied to assess the risks of equipments in ethylene facilities of petrochemical plants. Thereby, more realistic evaluation results were obtained and applicability of the proposed RBI program was proven.

• Nuclear Engineering and Technology
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• 제55권11호
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• pp.4159-4166
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• 2023

Laser decontamination of radioactive surfaces is an innovative technology. Our contribution to improving this technology includes studies on laser beam decontamination with a pulsed laser of an average power of 150 W, equipped with a hand guided working head. Our investigations are focused on metallic surfaces typical in nuclear power plants, such as stainless steel, bright and rusted mild steel, galvanized steel, and painted steel. As typical nuclides of contaminated surfaces we chose Co-60 and Cs-137, the most frequently occurring nuclides in many nuclear plant components; Sr-85 as a representative of Sr-90, the potentially most harmful fission nuclide; and Am-241 as a representative of the minor alpha-radiation emitting actinides. Here, we present our results of decontamination and recovery ratios. Decontamination ratios of 90-100% were achieved on different surfaces.

• Journal of Radiation Protection and Research
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• 제33권4호
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• pp.183-196
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• 2008

원전주변의 주민에 대한방사선량의 대부분을 음식물 섭취에 의한 내부피폭이 차지하고 있다. 그러나 우리나라 원전에 적용하고 있는 음식물 섭취 관련 인자는 1989년 한국원자력연구소가 고리원전 주변지역을 대상으로 수행한 현장조사 결과를 계속 적용하고 있어 최근의 식습관 변화를 적절히 반영하지 못하고 있다. 또한 우리나라는 미국 NRC (Nuclear Regulatory Commission) 에서 적용하고 있는 최대개인에 근거하여 음식물 섭취율을 결정하고 있다. 그러나 최근의 ICRP (International Commission on Radiological Protection) 의 권고 및 유럽의 관련 지침에서는 결정집단 또는 결정집단을 대표하는 개인에 대해 선량을 평가토록 권고하고 있다. 따라서 이러한 식습관의 변화추이나 피폭평가대상에 대한 국제적인 권고기준에 준하는 음식물 섭취율 설정방법에 대한연구가 필요하다. 보건복지가족부에서는 국민건강증진법에 의거 매 3년마다 전국 규모의 국민의 식품 및 영양섭취실태 조사를 실시하고 있다. 따라서 본 연구에서는 이러한 정부조사자료를 활용하여 주기적으로 음식물 섭취량 자료를 갱신할 수 있는 방안을 연구하였다. 보건복지가족부에서 $2001{\sim}2002$년에 수행한 국민영양조사원자료(raw data)를 분석하여 결정집단을 대표하는 개인의 음식물 섭취율을 결정하는데 이용할 수 있는 기초통계량을 제시하고, 또한 현재 국내 원전에서 적용하고 있는 최대개인의 음식물 섭취율을 재설정하였다.