• Journal of Korean Society of Forest Science
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• v.74 no.1
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• pp.67-81
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• 1986

To investigate the stand structure of the stocked broad-leaved forests in Korea, 1,000 plots, allocated by systematic sampling method, were interpreted on the aerial photographs accompanied with ground survey. Total area of the stocked broad-leaved forests except Jeju island was 818,286ha and the percentage to total forest area was 12.7%. Total stock volume of the stocked broad-leaved forests was $38,890,779m^3$ and the percentage to total stocked forest volume was 27.4%. Mean number of trees per ha was 947 trees/ha, basal area was $11.17m^3/ha$, DBH was 11.30cm, tree height was 7.65m, stock volume was $44.96m^3/ha$, and current annual volume increment was $3.64m^3/ha$ in total land. The 64.7, 79.8 and 52.7 percent of the stocked broad-leaved forest area were distributed at elevations of 300-900m, in slope degree of above 25, and in northern aspect, respectively. Standfactors were apt to get better with the increase of distance from the car road way and the village, and with the increase of elevation belt.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.2
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• pp.67-77
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• 2015

The purpose of this paper is to draw historic valuable resources to conserve through the analysis about the preservation status of historic urban environment in Suwon Hwaseong Fortress. As for the conservation of urban environment, it is important to protect the resources showing historical continuity and to manage the resources remaining characteristics of place, the analysis of the preservation status is focused on the perspective of preservation of physical form and land use. This paper makes progress through three phases. First, in order to understand urban environment in Hwaseong Fortress overall, it compares land registration original map in 1911 to current map in 2014 by the four items of topography, water environment, streets and sites. Next, changes of four items in urban environment have been reviewed further by the research of maps, relative literatures, field survey and interview, and are classified according to the criteria of preservation-partially preservation-disappearance. After analysing preservation status, valuable urban historic cultural resources are drawn separately by being preserved continually and by being preserved partially but remaining characteristics of place. As a result, natural factors of topography and waterway and urban factor of streets are remained considerably preserved. And even if these factors are changed, the ground environment features support to understand historic urban context. Second, as preservation of topography, water environment, streets and sites are closely related to each other, integrated conservation frameworks are needed to enhance urban historic landscape. Third, modern historic resources in Hwaseong are remained unchanged and thus it is necessary to understand urban historic environment by the layers of various times besides Joseon Dynasty period. Fourth, historic sites and streets which had been preserved through urban development process are destroyed by recent historic cultural restoration policies, therefore urban historic resources worthy of conservation should be treated prudently.

• Journal of Radiation Protection and Research
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• v.39 no.3
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• pp.127-133
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• 2014

North Korea's uranium enrichment facility is a matter of international concern. It is of particular alarming to South Korea with regard to the security and safety of the country. This situation requires continuous monitoring of the DPRK and emergency preparedness on the part of the ROK. To assess the detectability of an undeclared uranium enrichment plant in North Korea, uranium concentrations in the air at both a short and a long distance from the enrichment facility were estimated. $UF_6$ source terms were determined by using existing information on North Korean facility and data from the operation experience of enrichment plants from other countries. Using the calculated source terms, two atmospheric dispersion models (Gaussian Plume Model and HYSPLIT models) and meteorological data were used to estimate the uranium particle concentrations from the Yongbyon enrichment facility. A maximum uranium concentration and its location are dependent upon the meteorological conditions and the height of the UF6 release point. This study showed that the maximum uranium concentration around the enrichment facility was about $1.0{\times}10^{-7}g{\cdot}m^{-3}$. The location of the maximum concentration was within about 0.4 km of the facility. It has been assumed that the uranium sample of about a few micrograms (${\mu}g$) could be obtained; and that few micrograms of uranium can be easily measured with current measurement instruments. On the contrary, a uranium concentration at a distance of more than 100 kilometers from the enrichment facility was estimated to be about $1.0{\times}10^{-13}{\sim}1.0{\times}10^{-15}g{\cdot}m^{-3}$, which is less than back-ground level. Therefore, based on the results of our paper, an air sample taken within the vicinity of the Yongbyon enrichment facility could be used to determine as to whether or not North Korea is carrying out an undeclared nuclear program. However, the air samples taken at a longer distance of a few hundred kilometers would prove difficult in detecting a clandestine nuclear activities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.2021-2031
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• 2013

Due to the rapid economic growth within the nation, the quality of life of individuals have improved dramatically. The scope of living activities of individuals have also extended, resulting in a rapidly increasing demand for automobiles. The number of vehicles registered in Korea is rapidly increasing and will reach 188.71 million as of December 2012. Compared to the registered residents of 50.94 million provided by the Ministry of Public Administration and Security, the registered population reflects about 4 people per every automobile. Due to the high demands for vehicles, the demands for parking lots in collective housing and businesses are also increasing. In reality, the current state of expansion of parking lots are underground, due to the limited available space on ground level. Specifically, the slope of a parking lot cannot exceed 17% linear slope and 14% curved slope according to the 'parking lot laws', however studies show that the driver feels at risk for safety when stopped on the parking ramp while driving in the parking lot. This study seeks to examine the suitability of parking lot ramps, concerning the safety aspects of the driver. First, the ramp type was categorized as linear or curved, then test drives were performed based on variations of slopes, slant distances, directions and points. A survey was administered to the driver after the completion of the test drive, in order to element design for an ideal ramp. In the case of curved ramp, the results of the estimate suggests a counterclockwise, slope at a maximum of 12% incline. The maximum slope for a linear ramp was analyzed to be between 13~14%, suggesting that slope greater than 15% need to be eliminated. In conclusion, it is anticipated that the element design parking ramp reported in this study will help to serve as a reference for future parking lot related guidelines, and provide cost effective traffic safety mechanisms in future parking lot businesses to follow.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.2
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• pp.70-77
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• 2008

In this study, to establish countermeasure from marine casualties as a basic study fur long-term prediction of topographical change around Jinudo in the Nakdong river estuary, spatio-temporal topographical change monitoring was carried out. Also, in order to estimate the deposition variations concerning SS (Suspended Solid) flux which moved at St.S1 during neap and spring tide, respectively. From the topographical monitoring, it was found that the annual mean ground level and deposition rate were 141 mm and 0.36 mm/day and all parts except the northern part of Jinudo had the active topographical changes and a tendency to annually deposit. From vertical distribution of SS net fluxes, $SS_{LH}$ (latitudinal SS net flux) during spring tide overall flows average 28 $kg/m^2/hr$ (eastward), and $SS_{LV}$ (longitudinal SS net flux) flows average 11.1 $kg/m^2/hr$ (northward). And, $SS_{LH}$ overall flows average 4.8 $kg/m^2/hr$ (eastward), and $SS_{LV}$ flows average 1.5 $kg/m^2/hr$ (northward) during neap tide similar with spring tide. The depth averaged values of the latitudinal and longitudinal SS net fluxes during spring tide were approximately 6 times higher than those during neap tide. As result of, it was considered that topographical change of southern part of Jinudo was affected by resuspension of bottom sediments due to strong current in bottom layer during flood flow.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.2
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• pp.156-163
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• 2002

In order to development the construction and dimension of fishing gear for gizzard shad coastal purse seine, first of all investigated to the sinking speed and underwater geometry of net, behaviour of fish school to the net during the fishing operation In the field. The results obtained are summarized as follows; 1. Average sinking speed of net was 13cm/sec in bunt, 9.0cm/sec and 9.5cm/sec in 170m and 280m of center, 4.9cm/sec in end wing side, therefore was fastest in start of shooting and decreased gradually during the shooting process. 2. The most of leadline was reached in bottom from the shooting immediately to hauling time and the mean depth of timber bar used equipment for the escaping prevention of fish school was within the 2.7m. 3. The fish school of gizzard shad was appearanced higher density and remained to the most time in bottom than the surface and repeated to vortical movement, and its tendency to distinct in rapid time of tide current. 4. Behaviour of fish school in the net was showed to the vortical movement by sinking and rising immediately with the shooting of net and then divide with the two shape to follow round the wall of net and no patterns straightly movement in the net, and tendency easily catched in fish school of the wall of net. 5. Escaping of fish school in the gap of wing side was to busy after that seting the timber bar, therefore its function for escaping prevention of fish school was very lowed. 6. Escaping behaviour of fish school was differenced with the depth of fishing ground, the above 20m escaped to busy through the below in ledline because the sinking speed of fish school is fast than the net.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.2
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• pp.2262-2275
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• 1971

Fourteenes rervoirs maintained by the local land improvement associations in the province of Chullabuk-Do and 20 reservoir maintained by thos in the province of Chullanam-Do, were surveyed in connection with a correction between storage capacity and sediment deposit. In addition to this survey, 3,347 of small reservoir, that lie scattered around in the above-mentioned two provinces were investigated by using existing two provinces were investigated by using existing records pertaining to storage capacity in the office of City and country, respectively. According to this investigation the following comclusions are derived. 1. A sediment deposition rate is high, being about $10.63m^3/ha$ of drainage area, and resulting in the average decreasc of storage capaity by 27.5%. This high rate of deposition coule be mainly attributed to the serve denudation of forests due to disorderly cuttings of trees. Easpecially, in small reservoir, an original average design storage depth of 197mm in irrigation water depth is decreased to about 140mm. 2. An average unit storage depth of 325.6mm as the time of initial construction is decreased to 226mm at present. This phenomena causes a greater shortage irrigation water, since it was assumed that original storage quantity was already in short. 3. Generally speaking, seepage rates through dam abutment intakepipe, etc, are high due to insufficient maintenance and management of reservoir. 4. It is recommended that sediment deposit should be dredged when a reservoir is dry in drought. 5. Farmers usually waste excessive irrigation water. 6. Water saving methods should be practiced by applying only necessary water for growing stage of rice. 7. In are as where water defficiency for irrigation is severe, a soil moisture content should be kept at about 70% by applying water once in several days. 8. Tube wells should be provided so as to exploit ground water and subsurface current below stream bed as much as possible. 9. If an intake weir was constructed, a water collection well should be built for the use in drought. 10. Water conservation should be forced by converting devastated forests contained in the drainage area of reservoir to protected forests so as to take priority of yrefor estation, gully control, the prohibition of disorderly cutting of trees, etc. 11. Collective rice nurseries should be adopted, and it should be recommended that irrigation water for rice nurseries is supplied by farmer themselves. 12. Sediment desposit in reservoir should be thoroughly dreged so as to secure a original design storage capacity. 13. The structure of overflow weir should be automatic so as to freely control flood level and not to increase dam height.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.413-433
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• 1994

Jinhae Bay once was a productive area of fisheries. It is, however, now notorious for its red tides; and oxygen deficient water-masses extensively develop at present in summer. Therefore the shellfish production of the bay has been decreasing and mass mortality often occurs. Under these circumstances, the three-dimensional numerical hydrodynamic and the material cycle models, which were developed by the Institute for Resources and Environment of Japan, were applied to analyze the processes affecting the oxygen depletion and also to evaluate the environment capacity for the reception of pollutant loads without dissolved oxygen depletion. In field surveys, oxygen deficient water-masses were formed with concentrations of below 2.0mg/l at the bottom layer in Masan Bay and the western part of Jinhae Bay during the summer. Current directions, computed by the $M_2$ constituent, were mainly toward the western part of Jinhae Bay during flood flows and in opposite directions during ebb flows. Tidal currents velocities during the ebb tide were stronger than that of the flood tide. The comparision between the simulated and observed tidal ellipses showed fairly good agreement. The residual currents, which were obtained by averaging the simulated tidal currents over 1 tidal cycle, showed the presence of counterclockwise eddies in the central part of Jinhae Bay. Density driven currents were generated southward at surface and northward at the bottom in Masan Bay and Jindong Bay, where the fresh water of rivers entered. The material cycle model was calibrated with the data surveyed in the field of the study area from June to July, 1992. The calibrated results are in fairly good agreement with measured values within relative error of $28\%$. The simulated dissolved oxygen distributions of bottom layer were relatively high with the concentration of $6.0{\sim}8.0mg/l$ at the boundaries, but an oxygen deficient water-masses were formed within the concentration of 2.0mg/l at the inner part of Masan Bay and the western part of Jinhae Bay. The results of sensitivity analyses showed that sediment oxygen demand(SOD) was one of the most important influence on the formation of oxygen depletion. Therefore, to control the oxygen deficient water-masses and to conserve the coastal environment, it is an effective method to reduce the SOD by improving the polluted sediment. As the results of simulations, in Masan Bay, oxygen deficient water-masses recovered to 5.0mg/l when the $50\%$ reduction in input COD loads from Masan basin and $70\%$ reduction in SOD was conducted. In the western part of Jinhae Bay, oxygen deficient water-masses recovered to 5.0mg/l when the $95\%$ reduction in SOD and $90\%$ reduction in culturing ground fecal loads was conducted.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.6
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• pp.449-469
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• 2011

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering during 2010. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery, and new and renewable energy. Various topics were presented in the field of general thermal and fluid flow. Research issues mainly focused on the thermal reliability of axial fan and compressor in the field of fluid machinery. Studies on the design of ground source heat pump systems and solar chemical reactors were executed in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (3) Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and CO2 were studied. Performance improvement of refrigeration systems are tried applying various ideas of refrigerant subcooling, dual evaporator with hot gas bypass control and feedforward control. The hybrid solar systems combining the solar collection devices with absorption chillers or compression heat pumps are simulated and studied experimentally as well to improve the understanding and the feasibility for actual applications. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. Various studies on heating and cooling systems, HVAC facilities, indoor air environments and energy resources were carried to improve the maintenance and management of building service equipments. In the field of heating and cooling systems, papers on a transformer cooling system, a combined heat and power, a slab thermal storage and a heat pump were reported. In the field of HVAC facilities, papers on a cooling load, an ondol and a drying were presented. Also, studies on HVAC systems using unutilized indoor air environments and energy resources such as air curtains, bioviolence, cleanrooms, ventilation, district heating, landfill gas were studied. (5) In the field of architectural environment and energy, studies of various purposes were conducted such as indoor environment, building energy, renewable energy and green building. In particular, renewable energy and building energy-related researches have mainly been studied reflecting the global interest. In addition, many researches which related the domestic green building certification of school building were performed to improve the indoor environment of school.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.95-95
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• 2017

Lodging is a serious issue in rice production, because it drastically decreases the biomass production and grain yield. Since the Green Revolution, the lodging resistance has been increased by lowering the moment of above-ground parts due to the short culm by the semi-dwarf gene sd1. However, it has been pointed out that sd1 alone has suppressive effects for biomass production and yield. To increase rice yield, the long-culm and large panicle type varieties with a superior lodging resistance need to be developed. To improve the lodging resistance and yield of these type varieties, it would be effective to identify novel alleles for these traits underlying natural variations in rice and to pyramid these alleles to a single rice variety. In order to perform this strategy, we have developed new rice lines derived from crosses among varieties with superior alleles. At first, TULT-gh-5-5 was selected from a cross between strong culm and high biomass variety Leaf Star and high-yielding variety Takanari, and TUAT-32HB was selected from a cross between high-yielding variety Akenohoshi and Takanari. Then, we developed the super thick-culm and super grain-bearing line, LTAT-29 derived from a cross between TULT-gh-5-5 and TUAT-32HB. In the current study, to identify the QTLs and genes relating to the strong culm and the high yield of LTAT-29, we performed QTL analysis using SNPs markers with $F_2$ population derived from a cross between LTAT-29 and Takanari. LTAT-29 has never lodged throughout the growth period despite it had long culms and heavy panicles. LTAT-29 had a larger outer diameter of the culm and twice the size of the section modulus than Takanari. As a result, the bending moment at breaking of LTAT-29 was significantly larger than that of Takanari. Brown rice yield of LTAT-29 was $9.2t\;ha^{-1}$ about 10% higher than that of Takanari due to the larger number of spikelets per panicle. LTAT-29 had a greater number of secondary branches per panicle. In the $F_2$ population between LTAT-29 and Takanari, we found continuous frequency distributions in the section modulus and the spikelet number per panicle. Two QTLs increased the section modulus by the alleles of LTAT-29 were detected on Chr.1L and Chr.2L. One QTL increased the spikelet number per panicle of Takanari by the allele of LTAT-29 was detected on Chr.1L, and two QTLs increased the number of secondary branches per panicle by the alleles of LTAT-29 were detected on Chr.1L and Chr.4L. It was found that the alleles of these QTLs were the japonica type originated from Leaf Star or Akenohoshi. The novel QTLs for the traits related to super thick-culm and super grain-bearing and their combinations could be utilized for improving the lodging resistance and yield in rice varieties.