• 한국토양비료학회지
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• 제19권3호
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• pp.251-268
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• 1986

Selecting a site for the safe disposal of radioactive waste requires the evaluation of a wide range of geologic, mineralogic, hydrologic, and physicochemical properties. Although highly diverse, these properties are in fact interrelated. Site requirements are also diverse because they are influenced by the nature of the radionuclides in the waste, for example, their half-lives, specific energy, and chemistry. A fundamental consideration in site selection is the mineralogy of the host rock, and one of the most ubiquitous mineral groups is clay minerals. Clays and clay minerals as in situ lithologic components and engineered barriers may playa significant role in retarding the migration of radionuclides. Their high sorptivity, longevity (stability), low permeability, and other physical factors should make them a very effective retainer of most radionuclides in nuclear wastes. There are, however, some unanswered questions. For example, how will their longevity and physicochemical properties be influenced by such factors as radionuclide concentration, radiation intensity, elevated temperatures, changes in redox condition, pH, and formation fluids for extended periods of time? Understanding of mechanisms affecting clay mineral-radionuclide interactions under prevailing geochemical conditions is important; however, the utilization of experimental geochemical information related to physicochemical properties of clays and clay-bearing materials with geohydrologic models presents a uniquely challenging problem in that many assessments have to be based on model predictions rather than on experiments. These are high-priority research investigations that need to be addressed before complete reliance for disposal area performance is made on clays and clay minerals.

• 한국환경과학회지
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• 제31권5호
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• pp.389-404
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• 2022

The purpose of this study is to evaluate the vegetation recovery status of Mudeungsan National Park Jungmeorijae, Jeungsimsa district restoration site, and the Shimwon Valley ecological landscape restoration site in Jirisan National Park. Compared to the control plots, the Jungmeorijae restoration site was analyzed to have height growth of about 73.5%, the average species diversity index of about 75.2%. and the average similarity index was recovered to 7.75%. In the case of the restoration site in Jeungsimsa district, the height growth compared to the control plots was about 69.2%, the average species diversity index was about 55.0%. and the average similarity index was recovered to 25.65%. In the case of the Shimwon Valley ecological landscape restoration area, the height growth compared to the control plots was about 32.6%, the average species diversity index about 176.7%. and the average similarity index was recovered to 0.85%. The restoration site of the Jeungsimsa district was planted with relatively large trees during restoration work, and it took a relatively long time(20 years). Also, the site had less limiting factors due to the low elevation, allowing the degree of vegetation recovery to be higher than that of other sites.

• 한국산업보건학회지
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• 제17권2호
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• pp.111-119
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• 2007

Firemen are directly exposed to various harmful chemicals, physical factors and mental stress during rescue and fire-fighting. In fire extinguishing, unstable posture, poisonous gas, dust, high temperature and heavy equipments are possible hazardous factors. The alertness for emergency, shift work, job strain and stress are also possibly hazardous. Therefore, this study aimed to investigate the prevalence of musculo-skeletal symptoms and job stress and to determine risk factors in firemen. This study was carried out in a group of 226 firemen in Busan City, Korea. Standardized Nordic Questionnaire was used to investigate the prevalence of musculo-skeletal symptoms and Psycho-social Well-being Index (abbreviated PWI) was used to investigate the prevalence of job stress. General and occupational characteristics were included education, marital status, alcohol and smoking history, working duration, and work shift system. Body mass index (BMI) scores were calculated by physical examination including height and weight. Concerning musculo-skeletal complaints, the commonest site was neck, and shoulder, lower back, upper back were the next. Complaint site above one area of body was about 80%. From multiple logistic regression analysis, working duration was significant variable in musculo-skeletal symptoms. Odds ratio were 15.4 in working duration. About 16.8% was high risk stress group. From multiple logistic regression analysis, shift work and alcohol drinking were significant variables in PWI scores. Odds ratios were 2.25 in shift work. Accordingly, interventions are needed for health promotion of long term and shift worker.

• Spatial Information Research
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• 제11권3호
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• pp.241-249
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• 2003

본 연구의 목적은 GIS 분석기법에 의해 북한의 경제활동에 최적인 산업입지 지역을 분석하기 위한 기초 자료를 제공하는데 있다. 이러한 목적을 달성하기 위해 먼저 남포지역이 사례지역으로 선정되었다. 이는 환경적 요인과 사회문화적 요소에 의해 최적의 입지지역을 구분하기 위함이다. 두 번째로 자연환경 요소인 토지이용 상태와 지형요소가 분석되었다. 토지피복도와 식생지수 분포도가 작성되었고, 고도와 경사도 등을 분석하기 위해 수치고도모형이 작성되었다. 재해영향평가의 수단인 USLE는 산업단지 개발사업 도중의 환경변화를 최소화하는 방안으로 제안되어 본 연구에 적용되었다. 본 연구에서는 GIS와 USLE의 분석에 의해 환경변화를 최소화하는 최적의 산업입지지역 선정 방안을 제안하였다.

• Wind and Structures
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• 제18권4호
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• pp.423-441
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• 2014

The high frequency base balance (HFBB) technique is a convenient and relatively fast wind tunnel testing technique for predicting wind-induced forces for tall building design. While modern tall building design has seen a number architecturally remarkable buildings constructed recently, the characteristics of those buildings are significantly different to those that were common when the HFBB technique was originally developed. In particular, the prediction of generalized forces for buildings with 3-dimensional mode shapes has a number of inherent uncertainties and challenges that need to be overcome to accurately predict building loads and responses. As an alternative to the more conventional application of general mode shape correction factors, an analysis methodology, referred to as the linear-mode-shape (LMS) method, has been recently developed to allow better estimates of the generalized forces by establishing a new set of centers at which the translational mode shapes are linear. The LMS method was initially evaluated and compared with the methods using mode shape correction factors for a rectangular building, which was wind tunnel tested in isolation in an open terrain for five incident wind angles at $22.5^{\circ}$ increments from $0^{\circ}$ to $90^{\circ}$. The results demonstrated that the LMS method provides more accurate predictions of the wind-induced loads and building responses than the application of mode shape correction factors. The LMS method was subsequently applied to a tall building project in Hong Kong. The building considered in the current study is located in a heavily developed business district and surrounded by tall buildings and mixed terrain. The HFBB results validated the versatility of the LMS method for the structural design of an actual tall building subjected to the varied wind characteristics caused by the surroundings. In comparison, the application of mode shape correction factors in the HFBB analysis did not directly take into account the influence of the site specific characteristics on the actual wind loads, hence their estimates of the building responses have a higher variability.

• Asian Journal of Atmospheric Environment
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• 제8권3호
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• pp.126-139
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• 2014

In order to estimate the influence of sources on $PM_{2.5}$ in the industrial area of Japan, we carried out a source analysis using chemical component data of $PM_{2.5}$. $PM_{2.5}$ samples were collected intermittently at an industrial area in Japan from July 2010 to November 2012. Water soluble ions ($Cl^-$, $NO_3{^-}$, $SO{_4}^{2-}$, $Na^+$,$NH_4{^+}$, $K^+$, $Mg^{2+}$, $Ca^{2+}$), elements (Al, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Sb, Pb), and carbonaceous species (OC, EC) of the $PM_{2.5}$ (a total of 198 samples) were analyzed. Positive Matrix Factorization (PMF) model was applied to the data of those chemical components to identify the source of $PM_{2.5}$. At this observation site, nine factors were extracted. The major contributors of $PM_{2.5}$ were secondary sulfate 1, in which loading factors of $SO{_4}^{2-}$ and $NH_4{^+}$ were large (percentage source contribution: 20.9%), traffic, in which loading factors of OC (organic carbon) and EC (elemental carbon) were large (20.8%), secondary sulfate 2, in which loading factors of K and $SO{_4}^{2-}$ were large (8.0%), steel mills (7.8%), secondary chloride and nitrate (7.0%), soil (5.0%), heavy oil combustion (3.8%), sea salt (3.8%), and coal combustion (2.3%). The conditional probability function (CPF) and the potential source contribution function (PSCF) were carried out to examine the influence of a regional source and a broad-based source, respectively. CPF results supported local source influences such as steel mills, sea salt, traffic, coal combustion, and heavy oil combustion. PSCF results suggested that ships in the East China Sea, an industrial area of the east coastal region of China, and an active volcano in the Kyushu region of Japan were potential regional sources of secondary sulfate 1. Secondary sulfate 2 was affected by the burning of biomass fields and by coal combustion in Chinese urban areas such as Beijing, Hebei, and western Inner Mongolia. Source characterization using continuous data from one site showed a potential source representing fossil fuel combustion is affected both by regional and broad-based sources.

• 한국환경과학회지
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• 제13권5호
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• pp.479-488
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• 2004

Five sediment cores from the tidal flat of artificial Lake Shihwa are analyzed in terms of sedimentology and geochemistry to evaluate the heavy metal contamination and redox condition of surficial sediment following the Shihwa seawall construction. The variability of concentrations of various elements depends on the depositional environment, and reflects the various redox conditions and sediment provenances. The amounts of Ti and Al and their ratio of Ti/ Al with respect to Li clearly indicate that there is an anthropogenic contribution to the surficial sediment. The high concentrations of heavy metals suggest an anthropogenic contribution at ST. 34 and ST. 22. Concentrations of most elements (Cr, Cu, Zn and Pb) are higher near the Shihwa-Banwol industrial complex than in the central part of Lake Shihwa. Concentrations of heavy metal in surficial sediment near the Shihwa-Banwol industrial complex are two to eight times higher than in the center of Lake Shihwa. Enrichment factors (EF), which are normalized by the unpolluted shale, suggests a significant metallic contamination near the Shihwa-Banwol industrial complex (SBIC). The redox condition is divided into two anoxic and mixed oxi $c_oxic zones based on the carbon:sulfur (C/S) ratios of organic matter and elemental relationships. Correlations among geochemical elements Mn, U and Mo are significantly different from site to site, and may therefore be an indicator of the spatial redox condition. Controlling factors for switching anoxic/oxic conditions are thought to be water depth and the differences in industrial effluent supply. The variations of the Cu/Mn ratio in the sediments confirms above mentioned spatial differences of a redox condition in part, and therefore shows a location-dependence redox condition in sediments at four other sites. The redox condition of the surficial sediment characteristics of the Shihwa Lake are controlled by its geographic location and water depth.th.

• 한국습지학회지
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• 제15권2호
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• pp.251-264
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• 2013

도요 물떼새들은 만조시에 해안 내륙 휴식지에서 휴식을 취하는데, 휴식지를 선택할 때 여러 가지 요소들을 고려한다. 우리는 도요 물떼새 8종(알락꼬리마도요 Numenius madagascariensis, 청다리도요 Tringa nebularia, 큰뒷부리도요 Limosa lapponica, 개꿩 Pluvialis squatarola, 민물도요 Calidris alpine, 중부리도요 Numenius phaeopus, 마도요 Numenius arquata, 뒷부리도요 Xenus cinereus)을 대상으로 휴식지의 시공간적 이용과 그 이용에 영향을 미치는 요인들을 분석하였다. 휴식지 내 고인 물의 면적과 길이, 기온, 풍속, 종별로 이동시기, 방해정도를 변수로 고려하였다. 시공간적으로, 이용하는 종이 달랐으며 개체수 또한 변동을 거듭하였다. 그리고 도요 물떼새의 휴식지 이용에 영향을 미치는 요인은 종-특이적이었다. 연구지역의 휴식지는 폐장한 새우양식장이었으나 조사 기간 중 염생습지에서 자라는 함초 Salicornia herbacea 농장으로 전환하였다. 휴식지가 필요한 상황에서, 도요 물떼새들의 생태를 기초로 해서 기존 휴식지를 관리할 것을 권한다. 더불어, 여름철 가뭄에는 양식장의 수문을 열어주어 도요 물떼새들이 물을 이용해 체온관리를 할 수 있게 해주고, 만조시 도요 물떼새들이 양식장 안으로 날아 들어올 수 있도록 새들이 휴식지를 찾기 시작하는 만조 전네 시간부터는 농장 작업을 안 할 것을 권한다.

• 한국환경보건학회지
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• 제38권5호
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• pp.407-414
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• 2012

Objectives: This study was performed to assess based on field investigation the distribution characteristics of airborne fungi in an area of Seongdong-gu, Seoul. Methods: Three sites, a living area, forest and traffic site, were selected for evaluation of monthly level of outdoor airborne fungi. An on-site survey was executed between January 2009 and December 2009. During the experimental period, air sampling was performed every month in the afternoon (2:00 pm-5:00 pm) using a cascade impactor. Results: Outdoor airborne fungi measured in Seoul, Korea over one year showed a concentration range from 850CFU $m^{-3}$ to 15,200CFU $m^{-3}$. The mean respirable fraction of outdoor airborne fungi was 67% compared to total concentration. Regardless of measurement site, there was no significant concentration difference in outdoor airborne fungi between periods of yellow dust and non-yellow dust (p>0.05). There was no significant correlation relationship between outdoor airborne fungi and atmospheric factors such as temperature and relative humidity. The predominant genera of airborne fungi identified were Aspergillus, Cladosporium, Paecilomyces and Penicillium. Conclusion: Monthly levels of outdoor airborne fungi were highest in April and November and lowest in August. In seasonal concentration distribution, the autumn showed the highest level of outdoor airborne fungi, followed by spring, summer and winter. In regional concentration distribution, the highest level of outdoor airborne fungi was generally found in the forest, followed by the living area and traffic site.

• 한국환경생태학회지
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• 제18권2호
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• pp.210-220
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• 2004

본 연구의 목적은 미선나무 자생지의 환경특성과 생육특성을 분석함으로써 보전 및 복원의 기초자료 제공을 위한 것이다. 토양의 종류는 사양토, 식양토, 미사질양토이고 화학적 특성간 상관성은 전질소량과 양이온치환용량이 높게 나타났다. 생육특성의 경우 수고와 줄기직경은 I지역에서, 수관폭은 II지역에서, 엽수는 V지역에서, 종자수는 IV지역에서 타 지역에 비해 양호하였다. 생육특성에 대한 상관성에서는 수폭과 줄기직경이 높게 나타났다. 생장특성과 토양의 화학적 특성은 전기전도도와 수고가 높은 상관성을 보였다. 생육특성과 토양의 화학적 특성에 대한 회귀분석 결과, 수고와 전기전도도의 설명력은 약 70.4%. 엽수와 전질소량은 약 70.2%였다. 미선나무 자생지 보전 및 복원을 위해서 광도, 온도, 유전형질 등 다양한 인자들이 고려된 정밀 환경분석이 요구되어진다.