• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.232-239
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• 2001

For the purpose of providing the basic data on the improved fishing gear and the man power saving, which contribute to enhance fishing efficiency of set net in the coast of Jeju Island, this study analyzed the catch of two fishing place for the past 3 years in order to compare the fishing efficiency between rectngular set net and pound net, which have been used for fishing with being attached to the set net fishing place in coast of Jeiu Island, Thereby the result is as follows ; 1. When using pound net, the total amount of catch during 1997 to 1999 was 2 times more than that of when using rectangular set net. 2. When using Pound net, the catch of squid, mackerel, rabbit fish and Yellow tail during 1997 to 1999 was 1.8 times more than that of when using rectangular set net.. 3. In case of rectangular set net, CPUE marked 10.1㎏ with horse amckerel, 20.5㎏ with squid, 18.0㎏ with rabbit fish and 2.2㎏ with Yellow tail, and in case of pound net, CPUE marked 57.5 ㎏ with horse mackerel, 30.0㎏ with squid, 25.0 with rabbit fish and 4.7㎏ with yellow tail, and on the whole CPUE of poind net marked higher. 4. In case of rectangular set net, the catch ratio for fishing operation marked 64% with horse mackerel, 79% with squid, 39% with rabbit fish and 14% with yellow tail, and in case of pound net, the catch ratio fishing operation marked 18% with horse mackerel, 85% with souid 40% with rabbit fish and 14% with yellow tail, and accordingly it showed the result that the catch ratio for fishing operation was higher with the case of rectangular set net, but higher with the case of pound net.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.163-163
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• 2003

The study area, Kwangneung Experiment Forest (KEF) is located on the west-central portion of Korean peninsula and belongs to a cool-temperate broadleaved forest zone. At the old-growth deciduous forest near Soribong-peak (533.1m) in KEF, we have established a permanent plot and a flux tower, and the site was registered as a KLTER site and also a KoFlux site. In this study, we aimed to present basic ecological characteristics and synthetic data of carbon budgets and flows, and some monitoring data which are essential for providing important parameters and validation data for the forest dynamics models or biogeochemical dynamics models to predict or interpolate spatially the changes in forest ecosystem structure and function. We made a stemmap of trees in 1 ha plot and analyzed forest stand structure and physical and chemical soil characteristics, and estimated carbon budgets by forest components (tree biomass, soils, litter and so on). Dominant tree species were Quercus serrata and Carpinus laxiflora, and accompanied by Q. aliena, Carpinus cordata, and so on. As a result of a field survey of the plot, density of the trees larger than 2cm in DBH was 1,473 trees per ha, total biomass 261.2 tons/ha, and basal area 28.0 m2/ha. Parent rock type is granite gneiss. Soil type is brown forest soil (alfisols in USDA system), and the depth is from 38 to 66cm. Soil texture is loam or sandy loam, and its pH was from 4.2 to 5.0 in the surface layer, and from 4.8 to 5.2 in the subsurface layer. Seasonal changes in LAI were measured by hemispherical photography at the l.2m height, and the maximum was 3.65. And the spatial distributions of volumetric soil moisture contents and LAIs of the plot were measured. Litterfall was collected in circular littertraps (collecting area： 0.25m2) and mass loss rates and nutrient release patterns in decomposing litter were estimated using the litterbag technique employing 30cm30cm nylon bags with l.5mm mesh size. Total annual litterfall was 5,627 kg/ha/year and leaf litter accounted for 61% of the litterfall. The leaf litter quantity was highest in Quercus serrata, followed by Carpinus laxiflora and C. cordata, etc. Mass loss from decomposing leaf litter was more rapid in C. laxiflora and C. cordata than in Q. serrata litter. About 77% of C. laxiflora and 84% of C. cordata litter disappeared, while about 48% in Q. serrata litter lost over two years. The carbon pool in living tree biomass including below ground biomass was 136 tons C/ha, and 5.6 tons C/ha is stored in the litter layer, and about 92.0 tons C/ha in the soil to the 30cm in depth. Totally more than about 233.6 tons C/ha was stored in DK site. And then we have drawn a schematic diagram of carbon budgets and flows in each compartment of the KEF site.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.6
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• pp.45-52
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• 2019

As international criteria and standards are required in the fields of design and construction, landscape performance must also be considered not only for the value of the landscape but also for providing quality assurance and sustainability. Given the lack of research on landscape performance, the present research was purposed to analyze the importance of potential assessment categories and items using an analytical network process. A list of assessment items, which is composed of 20 items and 6 categories, was derived through a literature review and a preliminary survey of 11 landscape professionals. An ANP model was established and a survey was conducted among 30 landscape practitioners to determine the weight of priorities considering the criteria. The results of ANP showed that the categories of site selection, preservation and health, and convenience had high priorities while materials had the lowest importance score. For the assessment items, a monitoring plan was the highest importance, followed by cultural/ historic preservation, management cost reduction, and natural ground areas. Despite the difficulties in quantifying landscape achievements, most respondents agreed that there needs to be an evaluation system for landscape performance in order to assure the quality and sustainability of landscape development. More research and discussion are needed to develop an assessment system for landscape performance that is applicable to Korean context.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.607-613
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• 2006

For the reasonable use of low grade-shallow geothermal energy by Standing Column Well(SCW) system, the basic requirements are depth-wise increase of earth temperature like $2^{\circ}C$ per every 100m depth, sufficient amount of groundwater production being about 10 to 30% of the design flow rate of GSHP with good water quality and moderate temperature, and non-collapsing of borehole wall during reinjection of circulating water into the SCW. A closed loop type-vertical ground heat exchanger(GHEX) with $100{\sim}150m$ deep can supply geothermal energy of 2 to 3 RT but a SCW with $400{\sim}500m$ deep can provide $30{\sim}40RT$ being equivalent to 10 to 15 numbers of GHEX as well requires smaller space. Being considered as an alternative of vertical GHEX, many numbers of SCW have been widely constructed in whole country without any account for site specific hydrogeologic and geothermal characteristics. When those are designed and constructed under the base of insufficient knowledges of hydrgeothermal properties of the relevant specific site as our current situations, a bad reputation will be created and it will hamper a rational utilization of geothermal energy using SCW in the near future. This paper is prepared for providing a guideline of SCW design comportable to our hydrogeothermal system.

• School Mathematics
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• v.17 no.3
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• pp.377-390
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• 2015

This study attempts to analyse mathematical thinking and attitude of students related to mathematization in the problem solving process and provide implication of teachers' roles. For this, this study analyses mathematical thinking and attitude by dividing the process of solving problems of triangular array into several steps. And it makes a proposal for teachers questioning which can help students according to steps. Therefore this study results students' mathematization needs various steps and compositive mathematical thinking and attitude when students solve even a problem. From the point of view of teachers who attempt to wean students on mathematization, it is necessary for teachers to observe and analyze how students have mathematical thinking and take a stand for mathematics in detail. It also indicates that it is desirable for students who can not move on next step to provide opportunities to learn on their own rather than simply providing students mathematical thinking directly. Students can derive pleasure from the process of solving difficult problems through this opportunity and realize usefulness of mathematics. Finally this experience can build mathematical attitude and prepare the ground to be able to think mathematically.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.16-26
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• 2012

Pseudolites are ground-based transmitters that can be configured to emit GPS-like signals for enhancing the GPS by providing increased accuracy, integrity, and availability. However, a pseudolite (PL) can interfere with GPS satellite signals while it is transmitting or cause saturation to automatic gain control circuit. To solve these problems pulsing scheme is used, which transmits PL signal during a short period of time. In this paper the effect of the number of PL and pulsing scheme on the software GPS L1 and L2C signal acquisition performance is studied for the three pulsing schemes such as static pulsing, sweep pulsing, and pseudo random pulsing. For GPS L1 signal, static pulsing shows the best signal acquisition and tracking performance with one PL, and random pulsing shows the best performance with more than or equal to two PLs. For GPS L2C signal, all three pulsing schemes show the similar signal acquisition and tracking performance, but static pulsing shows a little better performance. For GPS L1 and L2C signals, software GPS receivers can do positioning with up to three PLs.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.457-466
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• 2009

This study puts the purpose in providing the scientific basis of dance motion as an artistic expression by analyzing the kinematic variable and the distribution factor of power affecting the motion, which is connected to the turn, right after the arabesque motion according to the existence and non existence of using the arm in the arabesque motion of modern dance. As a result of this study, arabesque turn motion, not using the upper limbs, used more turning force of head and body than the arabesque turn motion, using the upper limbs, and arabesque turn using the upper limbs obtained the turning force, using the right shoulder. The range of the hip joint on the left and the position change of left tiptoe in the Arabesque turn motion using the upper limbs is largely ascended to the vertical axis, while, the position of tiptoe in the Arabesque turn motion, not using the upper limbs is dropped to the lower part of each event. In the replacement of body center, Arabesque turn motion using the upper limbs is moved more to the turning axis than arabesque turn motion not using the upper limbs. As a result of maximum vertical ground reaction force, Arabesque turn motion using the upper limbs appeared to be a lower value than the Arabesque turn motion not using the upper limbs.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.563-573
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• 2017

Coal ash is generated from coal-fired thermal power plants every year. The remaining quantity of coal ash ends up in the landfills except for the recycled portion, and the existing ash pond capacity is limited almost. Currently, the difficulties are faced in building a new ash treatment plant because of the concerns about the environmental impacts of landfills at individual plant facilities. In terms of minimizing the environmental impact, the recycling and effective uses of coal ash are recognized as urgent issues to be challenged. Accordingly, this study examines the obstacles in expanding the recycling of the coal ash in South Korea and proposes solutions based on the case study analysis. The analysis results are as follows: 1) specific recycling guidelines and standards are required to be established in accordance with the contact medium (soil, ground water, surface water and sea water) and the chemical. 2) by providing the recognition environmentally safe in recycling the coal ash, transparency in establishing the planning stages and active communication with the community through promotion and research are essentially needed. 3) practical support system is required to encourage the power plant companies to use the coal ash as beneficial use.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.2
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• pp.160-164
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• 1999

Subsurface environments, including the intermediate vadose zone and aquifers, may be contributing to increased atmospheric concentrations of $N_2$O. Denitrification appears to be the major source of $N_2$O in the subsurface environment. In the intermediate vadose zone, the level of denitrifying activity is dependent on the soil morphology, particularly stratified layers within the soil profile, which impede water and solute movement and create conditions favorable for denitrification. Movement of organic C from the soil surface appears to support denitrifying activity by providing an energy source and increasing the consumption of $O_2$. Denitrirication and $N_2$O production have been observed in aquifers but appear to be of greatest significance in shallow unconfined aquifers. The lack of organic C, N $O_2$, or anaerobiosis is often a limiting factor for activity but seems to be site specific. The presence of denitrifying bacteria does not appear to be a major limitation, based on published results, but the ubiquity of denitrifiers in subsurface environments needs to be confirmed. The fate of the $N_2$O produced in subsurface environments is unknown. Transport of $N_2$O by up ward diffusion, by outgassing at contacts with surface waters, and by ground water use need to be quantified to determine the contribution to atmospheric $N_2$O. Contamination of subsurface environment with N $O_3$$^{ }$ and organics has the potential for increasing the contribution to atmospheric $N_2$O by enhancing denitrification .

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.369-374
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• 2015

This study analyzed analyzes the energy performance of six houses in Daejeon completed which were built in 2011. Observed The observed houses, which were all designed and constructed inof the same size and structure, are were highly insulated with triple Low-E coating windows; the insulation level of the walls is was $0.13W/m^2K$ and that of the roof is was $0.10W/m^2K$. As electric houses, all of the energy supplied to the houses, including for cooking, is was supplied by electricity. A and 3~4 kWp of photovoltaic system and a 3~5 kW of ground source heat pump (GSHP) were installed in each house tofor providing provide space heating/and cooling and hot water are installed. We constructed a Web-based remote monitoring system in order to understand energy consumption and the dynamic behavior of the energy system. T, and the results of our metering data analysis of 2013 are as follows. First, the annual residential energy consumption is was 4,400 kWh (${\sigma}=1,209$) and GSHP energy consumption is was 5,182 kWh (${\sigma}=1,164$). Second, residential energy consumption ranked highest in average energy usage, with at 45% of the total, followed by heating with at 30%, hot water supply with at 17% and cooling with at 6%. Third, the average energy independence rate is was 51.8%, the GFA (Gross gross floor area) criteria average energy consumption unit is was $48.7kWh/m^2yr$ (${\sigma}=10.1$), and the net energy consumption unit (except the energy yield of the PV systems) is was $24.7kWh/m^2yr$ (${\sigma}=8.8$).