• Journal of Korean Society of Environmental Engineers
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• v.32 no.9
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• pp.894-899
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• 2010

We coordinated the experiments with ozone pretreatment and two-phase anaerobic digestion using solid-liquid separation to raise the efficiency of sludge volume reduction and obtained the following results. The pre-treatment with ozone reduced the solid concentration in the average of TSS $8.3{\pm}2.0%$ TSS and $9.2{\pm}}2.8%$ VSS. Of the organic material, TCOD decreased $5.1{\pm}2.4%$, but SCOD showed $72{\pm}6.5%$ increased, which was due to destruction of the cell wall and dissolution of icell media by the powerful oxidative stress of ozone. During the two-phase anaerobic digestion process, we achieved the reduction of $21.5{\pm}3.4%$ TSS, $20.2{\pm}8.4%$ VSS, $32.1{\pm}7.9%$ TCOD and $22.1{\pm}7.2%$ SCOD in average. The maximum methane gas production were 177.6 mL per g TSS, 210.8 mL per g VSS, 127.0 mL per g TCOD and 1452.0 mL per g SCOD, respectively. Solid material reduction through the two-phase anaerobic digestion and MLE (Modified Ludzack-Ettinger) processes were 93.8% of TSS and 92.0% of VSS. We concluded that suggested two-phase anaerobic digestion and MLE process could achieve the reasonable production of biogas and a maximum reduction of the sludge volume.

• Wind and Structures
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• v.16 no.4
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• pp.301-322
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• 2013

Recent major post-hurricane damage assessments in the United States have reported that the most common damages result from the loss of building roof coverings and subsequent wind driven rain intrusion. In an effort to look further into this problem, this paper presents a full-scale (Wall of Wind --WoW--) investigation of external and underneath wind pressures on roof tiles installed on a low-rise building model with various gable roofs. The optimal dimensions for the low-rise building that was tested with the WOW are 2.74 m (9 ft) long, 2.13 m (7 ft) wide, and 2.13 m (7 ft) high. The building is tested with interchangeable gable roofs at three different slopes (2:12; 5:12 and 7:12). The field tiles of these gable roofs are considered with three different tile profiles namely high (HP), medium (MP), and low profiles (LP) in accordance with Florida practice. For the ridge, two different types namely rounded and three-sided tiles were considered. The effect of weather block on the "underneath" pressure that develops between the tiles and the roof deck was also examined. These tests revealed the following: high pressure coefficients for the ridge tile compared to the field tiles, including those located at the corners; considerably higher pressure on the gable end ridge tiles compared to ridge tiles at the middle of the ridge line; and marginally higher pressure on barrel type tiles compared to the three-sided ridge tiles. The weather blocking of clay tiles, while useful in preventing water intrusion, it doesn't have significant effect on the wind loads of the field tiles. The case with weather blocking produces positive mean underneath pressure on the field tiles on the windward side thus reducing the net pressures on the windward surface of the roof. On the leeward side, reductions in net pressure to a non-significant level were observed due to the opposite direction of the internal and external pressures. The effect of the weather blocking on the external pressure on the ridge tile was negligible.

• Journal of the Korean association of regional geographers
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• v.3 no.1
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• pp.155-163
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• 1997

The Mongolian ger is ideally suited to the mongol's steppe climate and the nomadic way of life. This is a multipurpose dwelling which can be easily collapsed, transported to another place and put up again fully preserving its original shape. The pastoral nomadic ger has two key components: the wooden framework and the felt cover. The wooden parts are the walls(khana), the long poles(un), the smoke escape(toono) and its supports(bagana). One wall consists of 10-15 branches of willow tree. each about 1.5m high bound together in a way making it possible to fold it for transportation and then unfold it like an accordion. The unfolded walls are connected to form a circle. The long poles(un) are fastened to the upper part of the walls, with the other end passed through the toono hole, the only sky window and smoke escape through it from the ger. The toono is propped up by two posts, called bagana. All this forms the wooden framework of the ger, which is covered with felt. When the herders fire up their metal stoves, the temperature inside the ger becomes quite comfortable. Because the nomads live in a climate where there is only one growing season in a year, they do not make long migrations to new pastures. Livestock subsist on standing vegetation for eight months of the year. The basic pasture migration strategy is to leave enough standing vegetation at the end of the growing season in September to suffice until the new growth appears the following May. Mongolians use a type of compressed tea leaf that is called "brick" tea in English because it is rock solid and roughly the shape of a brick. And they consume a larger percent(88%) of fat from animal products such as meat, milk, butter, and cheese than any other people in the world. Milk products made from the milk of sheep, yak, and goats are major foods in the nomad's diet, but they are produced mainly in summer when all the animals are lactating. Mongolians made their special nomadic food culture on the steppe.

• Journal of the Korean association of regional geographers
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• v.13 no.2
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• pp.156-170
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• 2007

The commerce and industry of Busan was developed because of good geographical conditions with harbor. After passing its settling-down and diffusing time, Busan has grown in the trade city. Busan has lost the competitive power of the port city since 2000, because of the weakness of its economic power which is caused by the secession of manufacturing industry and the decrease of resident population and foreign tourist. In order to overcome these weaknesses, it is necessary for Busan to take the innovative strategy for the activation of marine tourism. This goal can be achieved by the strong quality of the port city, the coastal terrain, the traditional industry and the international traffic. The aim of this paper is to explore the Innovative Strategy for the activation of marine tourism in Busan and to suggest the following proposal. First, the government must decide the base of marine tourism under the geography viewpoint of the coast and sea, and develope tourism resources after analyzing the identity of marine tourism base. Second, the core part along the selected bases of marine tourism must be constructed the tourism terminal as the landmark of Busan in order to concentrate foreign tourist. Third, after each base of marine tourism must become the resort for tourists, they are able to experience the activity of marine tourism in this resort. Therefore, each base must be specialized. Fourth, each base must be connected with the route of marine tourism Fifth, in order to overcome the off-season of marine tourism, winter tourism goods such as skates, skis, artificial sea-bathing pool, artificial swimming beach, artificial sled, artificial rock wall of coast, hot spring resort of salt water are required to be developed in the center of marine tourism base.

• Journal of Conservation Science
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• v.34 no.1
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• pp.11-21
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• 2018

The result of the study on the origin and preservation status of the 'Gongju Junghakdong old missionary house', the Registered Cultural Property No. 233, reveals that the building was approved on October 23, 1921, and missionary Alice H. Sharp was living in the building until her retirement from her missionary life of 39 years in Korea in 1939. In order to review internal and external preservation status of the building, condition of wood material, the composition of the window, the damage of the wall, and the leaning of the building were examined. In particular, in the case of window facilities, it is necessary to restore it to the original upper and lower sliding window. As a result of investigation of the preservation status of the external facilities, it is necessary to restore the original shape of the staircase and a deck of the building on south western side and the well. In addition, the results of the non-destructive diagnosis of the ground revealed that the building was built on uneven surface layer of 2-5 m thickness and the boundary between the surface layer and the upper part of the weathered rock is inclined following geomorphology. This phenomenon shows that when the water content of the ground increases in the rainy season, the bearing capacity of the ground is lowered, and there is a possibility of uneven subsidence. Especially, landslides may occur in case of heavy rain. Therefore, it is desirable to install a masonry facility at the southwest boundary of the site, and it is recommended to install a drainage facility to ensure rapid drainage.

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.1-7
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• 2007

Backgound: It has been shown that the endothelium of cardiac valves and adjacent great vessels have a reduced immune reaction compared to other vessels. We investigated the clinical feasibility of using immunologically untreated xenogenic valves, in a pig-to-goat pulmonary valve conduit implantation model. Material and Method: Porcine pulmonary valve conduits were prepared without specific immunologic treatment and implanted into the right ventricular outflow tract of goats while undergoing cardiopulmonary bypass. Two goats each were assigned to the following observation time intervals: one day, one week, three months, six months and twelve months. Echo-cardiographic examinations were performed prior to sacrifice of the goat to evaluate pulmonary valve function. After the xenograft specimens were retrieved, histological changes were evaluated microscopically. Result: Ten of the twelve animals survived the predetermined observation time intervals. Aneurysmal dilatations, of the anterior wall of the implanted pulmonary artery, were observed at each of three and twelve month-survival animals. A variable degree of pulmonary valve regurgitation was observed on echocardiography. However, valve stenosis, thrombotic occlusion and vegetation were not seen. Microscopically, the nuclei of the donor tissue disappeared as a result of pyknosis and karyolysis; however the three components of the implanted xenografts (the pulmonary artery, the valve and the infundibulum) were gradually replaced by host cells over time, while maintaining their structural integrity. Conclusion: Immunologically untreated xenogenic pulmonary valve conduits were replaced by host cells with few observed clinical problems in a pig to goat pulmonary valve implantation model. Therefore, they might be an alternative bioprosthesis option.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.252-262
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• 2019

Following the earthquake in Gyeongju (2016) and Pohang (2017), South Korea is no longer a safe place for earthquakes. Accordingly, the need for shelters suitable for disaster environments is increasing. In this study, a lightweight composite panel was used to produce post-disaster housing for refugees to compensate for the disadvantages of existing evacuation facilities. For this purpose, an evaluation of structural performance and thermal environment for post-disaster housing for refugees composed of lightweight composite panels was performed. To assess the structural performance, a lateral loading test was conducted on a system made of lightweight composite panels. The specimens consisted of two types, which differed according to the bonding method, as a variable. In addition, the seismic and wind loads were calculated in accordance with KBC 2016 and compared with the experimental results. Regarding the energy performance, optimization of south-facing window planning and window-wall ratio and solar heat gain coefficient were analyzed to minimize heating, cooling, and lighting energy. As a result, the specimens composed of lightweight composite panels will perform sufficiently safely for lateral loads and the optimized window planning will lead to a low-energy operation.

• 한국노년학
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• v.37 no.2
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• pp.497-516
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• 2017

This study explored the meaning and essential structure of the life of 12 older wage earners who are 65 years old or older residing in Seoul. For the in-depth analysis of the qualitative interviews, Giorgi(2012)'s phenomenological research method was used. Results presented a total of 349 meaning units, 35 core meanings, 16 emerging themes, and 6 essential themes. These essential themes consisted of a life tolerating contempt and prejudice, the hungry belly in the later years, a yoke of the subordinate, an unclimbable vertical wall, reviving the hours of youth through working, and labor pride. These six essential themes led to the essential structure of'small happiness that is felt at times out of the weary working life in later years. The research participants felt worn out by the social discrimination and unfair working conditions against older wage earners, but they felt relieved that they were able to work in old age and had a sense of self-esteem through their work. Working was the important tools for older wage earners to experience happiness in later years because it not only relieved their financial burden but also brought a sense of self-esteem and labor pride. Based on the results, we suggested as following: 1) with respect to social discrimination and unfair working conditions against older workers, the whole society should discuss it as the protection of human rights and take legal actions; 2) various service jobs need to be created so that older workers can contribute to the society by utilizing their experiences; and 3) educational programs of computer or internet use must be expanded through which older wage earners can improve their job skills.

• Journal of the Mineralogical Society of Korea
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• v.32 no.2
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• pp.87-102
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• 2019

Pallancata Ag mine is located at the Ayacucho region 520 km southeast of Lima. The geology of mine area consists of mainly Cenozoic volcanic-intrusive rocks, which are composed of tuff, andesitic lava, andesitic tuff, pyroclastic flow, volcano clasts, rhyolite and quartz monzonite. This mine have about 100 quartz veins in tuff filling regional faults orienting NW, NE and EW directions. The Ag grades in quartz veins are from 40 to 1,000 g/t. Quartz veins vary from 0.1 m to 25 m in thickness and extend to about 3,000 m in strike length. Quartz veins show following textures including zonation, cavity, massive, breccia, crustiform, colloform and comb textures. Wallrock alteration features including silicification, sericitization, pyritization, chloritization and argillitization are obvious. The quartz veins contain calcite, chalcedony, adularia, fluorite, rutile, zircon, apatite, Fe oxide, REE mineral, Cr oxide, Al-Si-O mineral, pyrite, sphalerite, chalcopyrite, galena, electrum, proustite-pyrargyrite, pearceite-polybasite and acanthite. The temperature and sulfur fugacity ($f_{s2}$) of the Ag mineralization estimated from the mineral assemblages and mineral compositions are ranging from 118 to $222^{\circ}C$ and from $10^{-20.8}$ to $10^{-13.2}atm$, respectively. The relatively low temperature and sulfur-oxygen fugacities in the hydrothermal fluids during the Ag mineralization in Pallancata might be due to cooling and/or boiling of Ag-bearing fluids by mixing of meteoric water in the relatively shallow hydrothermal environment. The hydrothermal condition may be corresponding to an intermediate sulfidation epithermal mineralization.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.16-24
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• 2021

This experimental study was conducted to evaluate the in-plane and out-of-plane seismic performances of an unreinforced masonry walls (URMs) strengthened with prestressed steel-bar truss systems developed in the present investigation. The truss systems were installed on both faces of the walls. All the wall specimens were subjected to lateral in-plane or out-of-plane cyclic loads at the fixed gravity stress of 0.25 MPa. The seismic performance of the strengthened specimens was compared to that measured in the counterpart URM. When compared with the lateral load-displacement curve of the URM, the strengthened walls exhibited the following improvements: 190% for initial stiffness, 180% for peak strength, 610% for accumulated energy dissipation capacity, and 510% for equivalent damping ratio under the in-plane state; the corresponding improvements under the out-of-plane state were 230% for initial stiffness, 190% for peak strength, 240% for accumulated energy dissipation capacity, and 120% for equivalent damping ratio, respectively. These results indicate that the developed technique is very promising in enhancing the overall seismic performance of URM.