• 한국환경보건학회지
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• 제20권4호
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• pp.1-9
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• 1994

In order to investigate the regional level of air pollutants at Kangwha island situated on the western coast in Korea, the suspended particulate matter samples were collected by using the low volume air sampler on ten interval from March 1992 to February 1993 and the mass concentration of suspended particulate matter (SPM) and the chemical composition of water-soluble major ionic components in SPM samples were measured. During the sampling period, the average concentration of SPM under diameter 10 $\mu$m was found to be 48 $\mu$g/m$^3$ (+ 12). The seasonal concentration of SPM was showed in order of spring>fall>winter>summer. It was considered that higher concentration on spring than other season was affected by the long-range transport of Yellow sand particulate from China continent and lower concentration on summer by the washout and rainout effect of large rainfall. The content of water-soluble component in SPM samples was founded to be about 31% (14.69 $\mu$g/m$^3$) and 65% was unknown or unanalyzed. The content of cationic component showed in order of NH$_4^+$ (44.6%)>Na$^+$ (21.2%)>K$^+$ (14.7%)>Ca$^{2+}$ (13.6%)>Mg$^{2+}$ (5.9 %) and the content of anionic component SO$_4^{2-}$ (62.5%)>NO$_3^-$ (22.3%)>Cl$^-$ (15.2%), respectively. This fact indicates that ammonium and sulfate ion of water-soluble component in SPM sample were dominant in this region. From the chemical composition of water-soluble component, the most of Na$^+$, Mg$^{2+}$ and Cl$^-$ were originated from seawater source but K$^+$, Ca$^{2+}$ and SO$_4^{2-}$ were originated from other non-marine source. The contribution of seasalt to the composition of precipitation was 23%.

• 천문학회보
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• 제38권1호
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• pp.32.2-32.2
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• 2013

We examine large-scale environmental effects on the formation and the mass growth of dark matter halos. To facilitate this, we constructed dark matter halo merger trees from a cosmological N-body simulation, which enabled us to trace the merger information and the assembly history of individual halos. In fact, since the massive halos are more likely to be distributed in denser regions than in less dense regions (Mo & White, 1996), the large-scale environment dependence of the properties of halos can be partly originated from the halo mass effect. In order to avoid such contamination, caused by the mass dependence of halo properties, we carefully measured the local overdensity as the indicator of large-scale environment, which was calculated to be as independent of halo mass as possible. Small halos (${\sim}10^{11-12}M_{\odot}$), which usually host isolated single galaxies, show a notable difference on the formation time of galaxies depending on their large-scale environments, which reconfirms halo assembly bias (Gao & White, 2007). Furthermore, we investigate how this environmental effect on small halos is correlated with the mass assembly history of galaxies by using our semi-analytic model. We found that assembly bias in small halos does not have significant effects on the formation time or on the star formation history of galaxies residing in those halos except for the individual stellar mass of galaxies at z = 0. On average, isolated galaxies in high-density regions tend to be slightly more massive than those in low-density regions. Although the observational data from the current galaxy surveys is not yet sufficient for testing this prediction, future galaxy surveys will be able to explore these small galaxies more thoroughly.

• Journal of Biosystems Engineering
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• 제5권1호
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• pp.33-42
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• 1980

This study was carried out to investigate the actual environmental paddy storage conditions in conventional Korean farm warehouses. The paddy storage conditions by the locations and sizes of warehouses were figured out. The effectiveness of the small insulated box for storing paddy was also examined. Observations were made at sixteen different warehouses located in Moonsan-Myeon, Jinyandg-gun, Gyungnam Province from July lst to September 28 th, the period which was considered to be the worst for storing grains. The results are as follows ; 1. the average temperatures of rough rice and air inside the warehouse were 0.9 and 0.7$^\circ$ higher than the outside air temperature. 2. The average relative humidity in warehouses was 1.5percent higher than that of the atomosphere. This fact resulted in the increased moisture content of grains. Therefore, the ventilation for equalizing the relative humidity of inside and outside of warehouses was required. 3. The dry matter of stored rough rice was decreased by 1.1 percent in average druing the observation period. In order to reduce the dry matter loss, application of new grain storing method ;hermetic storage or filling inert gas storage, was highly recommended. 4. Environmental conditions for storing rough rice in a warehouse located in a sloping site are, in general , better than those of a warehouse located in a flat site. But as far as the dry matter of rough rice was concerned, above situation is not always satisfactory. Because it is fairly frequent to observe the higher rate of moisture absorption by grains stored in a warehouse located in a sloping site. 5. Environmental conditions for storing rough rice in a large-scale warehouse were better than those in a small size warehouse. Therefore, it is advisible for farmers to store their grins in the large-scale warehouses commonly used by villagers. 6. It was undesirable to store rough in a insulated box.

• 천문학논총
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• 제30권2호
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• pp.331-333
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• 2015

Gravitational interactions - mergers and fly-by encounters - between galaxies play a key role as the drivers of their evolution. Here we perform a cosmological N-body simulation using the tree-particle-mesh code GOTPM, and attempt to separate out the effects of mergers and fly-bys between dark matter halos. Once close pair halos are identified by the halo finding algorithm PSB, they are classified into mergers ($E_{12}$ < 0) and fly-by encounters ($E_{12}$ > 0) based on the total energy ($E_{12}$) between two halos. The fly-by and merger fractions as functions of redshift, halo masses, and ambient environments are calculated and the result shows the following.(1) Among Milky-way sized halos ($0.33-2.0{\times}10^{12}h^{-1}M{\odot}$), $5.37{\pm}0.03%$ have experienced major fly-bys and $7.98{\pm}0.04%$ have undergone major mergers since z ~ 1; (2) Among dwarf halos ($0.1-0.33{\times}10^{12}h^{-1}M{\odot}$), $6.42{\pm}0.02%$ went through major fly-bys and $9.51{\pm}0.03%$ experienced major mergers since z ~ 1; (3) Milky-way sized halos in the cluster environment experienced fly-bys (mergers) 4-11(1.5-1.7) times more frequently than those in the field since z ~ 1; and (4) Approaching z = 0, the fly-by fraction decreases sharply with the merger fraction remaining constant, implying that the empirical pair/merger fractions (that decrease from z ~ 1) are in fact driven by the fly-bys, not by the mergers themselves.

• 대한환경공학회지
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• 제27권11호
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• pp.1141-1145
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• 2005

접촉부와 간헐포기부로 구성된 접촉조 결합형 연속회분식반응조를 질소제거를 위해 제안하고 실험적으로 연구하였다. 짧은 체류시간의 접촉반응을 통해 활성슬러지 플록에 유기물질이 생물흡착되지만 불완전 대사가 진행된다는데 근거를 두고 있다. 결과적으로 실하수의 경우 유입 유기물질의 61.2%가 접촉반응 30분 만에 흡착되었다. 유기물질의 비흡착량은 22.3 mg SCOD/g MLVSS였으며, 이는 후속되는 공정에서 탈질효율의 향상에 기여하였다. 연속운전을 통한 전체적인 처리효율은 TCOD/TKN 비가 6이하의 낮은 조건에서도 SCOD 및 T-N 제거율이 각 86%와 60%를 유지하였다.

• 한국광물학회지
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• 제15권3호
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• pp.195-204
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• 2002

광물조성과 노출표면적(exposed surface area)은 토양풍화속도 계산모델에 영향을 미치는 중요한 요인들이다. PROFILE 등 기존의 풍화속도 계산모델에서는 입도분석자료에 기초한 기하학적 계산값이나 $N_2$-BET 비표면적 등을 그대로 노출표면적으로 적용하고 있다. 그러나, 토양은 광물과 유기물의 혼합체로써 노출표면적을 정확히 구하기는 상당히 어려운 것이 사실이다. 본 연구에서는 유기물의 영향에 의한 토양광물의 노출표면적변화를 토양 깊이에 따른 peroxidation 전후의 N2-BET 비표면적값을 통해 살펴보고, 토양칼럼실험을 이용하여 풍화속도의 차이를 살펴보았다. 실험결과 peroxidation 후의 $N_2$-BET 비표면적은 1.68~4.87 $m^2$/g의 범위에서 증가하였으며, 깊이에 따라 증가하는 범위가 감소하는 경향을 보여주었다 이는 부식산 등 토양표면에 농집되어 존재하는 다양한 형태의 유기산 등이 광물의 노출표면적을 감소시키고 있다는 것을 의미한다고 할 수 있다 기존의 토양풍화속도 모델에서 토양광물 노출표면적변화 계산에 있어서 광물-유기산간의 결합에 의한 영향을 결합세기 측면에서 고려하고 정량화 하는 것이 향후과제라고 생각된다.

• 한국항해학회지
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• 제25권3호
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• pp.283-296
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• 2001

As a matter of fact, the document which has been developed to resolve the obvious conflicts between the interests of buyer and seller is the bill of lading. The bill of lading provides the seller with some security against default by the buyer and the buyer with some assurance of performance of the seller before the buyer is required to make payment. So to speak, the B/L provides some extent protection for both seller and buyer. This is a study on the construction of Liner Bill of Lading(Code name : CONLINEBILL) adopted by BIMCO(The Baltic and International Maritime Conference) and is using a basic bill of lading in the liner ships operation. In this study, the writer makes a wider and deeper study of rights of rights and obligations of Contract Parties by means of the rules of construction, specially focusing the Carriers liability under Carriage of Goods by Sea Act 1971(COGSA 1971), Hague-Visby Rules and Korea Commercial Law.

• The Korean Journal of Ecology
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• 제10권3호
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• pp.151-159
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• 1987

Relationships between soil factors and the growth of annual ring of Pinus densiflora grown on stony mountain were investigated at two sites of the different parent rocks: the one was formed by granite at Mt. Gwanag, Seoul and the other feldspar porphyry at Mt. Bipa, Daegu. The growth of annual ring was influenced by the physical factors of soil, such as soil depth, field caacity and water content of soil, rather than by the KDICical factors, such as total nitrogen, potassium, and calcium of soil. Of the soil factors affecting the growth of annual ring, soil depth, field capacity, water content of soil and organic matter closely interrelated with each other. All of these factors influenced water content of soil which might affect the water potential of Pinus densiflora leaves. In fact, the leaf water potential, affecting as the main factor for the growth of annual ring, of the pine grown in a deep soil was higher than that of the pine in a shallow soil.

• 상하수도학회지
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• 제19권6호
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• pp.728-737
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• 2005

Water quality of the Hwanggujicheon is poor because of the rapid housing and development in the large area of the basin. Establishment of water quality management strategy, based on the pollution sources survey and pollutant loads estimation, has to be established for the preservation of the stream water quality of the region. In this study, waste load allocation model to achieve the water quality goal of the stream and the optimization of pollutant load reduction, was developed. Nonpoint pollutant loads calculated by runoff model in the previous study are utilized for pollutant loads estimation of the drainage areas in this study. From the application result of the allocation model, water quality goals of the Hwanggujicheon that can be achieved as a matter of fact are BOD 8 mg/L. To achieve these goals, 23% of effluent BOD loads have to be reduced in the basin.

• 한국디지털건축인테리어학회논문집
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• 제4권2호
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• pp.19-25
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• 2004

This study is to furnish basic data for establishing the improvement counterplan of Housing environment and to solve the problem of Housing supply resulting from the continuous increase of population and to examine the historical flowing, the present condition and problems of Housing in Uijeongbu city. Including of the multi-house to the number of Housing, the supply ratio of Housing is 95% in quantity of the Housing in Uijeongbu city in 2004. Now, it is important time in the respect of quality as well as the quantity in supply matter of Housing. In fact, the main viewpoint in housing supply policy has been brought focus into the economic profits more than public interests. As a result of that, the residence environment has been worse. From now on, a Local autonomous entity including the construction authorities and Uijeongbu city authorities must focus on the public interests in solving problems of Housing.