• Journal of the Korean GEO-environmental Society
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• v.8 no.5
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• pp.5-14
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• 2007

The quantity of noxious wastes generated by the growth in industrialization and population in all over the world and its potential hazards in subsurface environments are becoming increasingly significant. The extraction of the contaminant from the soil and movement of the water are restricted due to the low permeability and adsorption characteristics of the reclaimed soils. Incorporated technique with PVDs have been used for dewatering from fine-grained soils for the purpose of ground improvement by means of soil flushing and soil vapor extraction systems. This paper is to evaluate several key parameters that affected to the performance of the PVDs specifically with regard to: well resistance of PVD, zone of influence, and smear effects. In the feasibility of contaminant remediation was evaluated in pilot-scale laboratory experiments. Well resistance is affected on the vertical discharge capacity of the PVDs under the various vacuum pressures. The discharge capacity increases consistently in areal extents with higher applied vacuum up to a limiting vacuum pressure. The head values for each piezometer at different vacuum pressures show that the largest head loss occurs within 14 cm of the PVD. Air flow rates and head losses were measured for the PVD placed in the model test box and the gas permeability of the silty soils was calculated. Increasing the equivalent diameter results in a decrease in the calculated gas permeability. It is concluded that the gas permeability determined over the 1,500 to 2,000 $cm^3/s$ flow rates are the most accurate values which yields gas permeability of about 3.152 Darcy.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.3
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• pp.333-341
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• 2014

Since distribution and preservation of cultural artifacts in the submarine sediments are directly affected by not only ocean currents and tides, but also their composition, it is very important to investigate geological characteristics of sediments and ocean-sediment interactions for maritime archaeological survey. Physical properties of submarine sediments, which are collected by grab sampler and vibro-corer, are analyzed in order to investigate effects of submarine environment on development of maritime archaeological survey techniques. Result of physical property analysis showed that bulk density, shear strength, and magnetic susceptibility increase with depth, while water contents and porosity decrease with depth. Since the magnetic susceptibility of bedrock is about 40 times that of submarine sediments, it might impact greatly on the response of magnetic survey. Physical properties of sediments with depth and sediment classification by Folk's ternary diagram indicate that submarine sediment mainly consists of silt, and cultural artifacts can not penetrate no deeper than 1.5 m in sediments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.246-258
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• 1988

Semi-quantitative analysis of $less-than-2{\mu}m$ clay minerals in thirty-nine superficial sediments from the Chinju Bay, southern coast of Korea, was made to reveal the distribution, provenance and dispersal pattern of fine-grained sediments. Additional nine samples were also taken from the Choryang Cheon (a river draining the kaolin-rich Hadong area) to investigate the influence of river a discharge. Grain size analysis for the Chinju Bay sediment samples was performed simultaneously as an aid to understand the sediment types and depositional environments. Except for the northeastern part, clayey mud predominates the entire bay. Average relative abundance of the four major clay minerals, I. I., illite, kaolinite, chlorite and smectite, is $55.1\%,\;23\%,\;21.5\%\;and\;0.4\%$, respectively. Although illite dominant clay mineral, the average content is about $10\~20\%$ tourer than that of the nearby continental shelf area. On the contrary, kaolinite content in the bay is about $10\%$ higher than that of the shelf area. Recent clay minerals of the Chinju Bay are mainly derived from the nearby inland area through numerous rivers and streams. Transport from shelf area, however. also seems to be important.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.393-397
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• 2006

Thuja koraiensis Nak. is a short and creeping evergreen shrub which reaches about 3 m in height and only occurs in the northeast China and in high mountains over the Korea. It's designated as a rare and endangered tree species in Korea and DD (data deficient) in Red List Category & Criteria of IUCN. This study was carried out to develop the propagation technique by cutting for conservation of genetic resources of T. koraiensis. The rooting responses of branch cuttings, obtained from hard (May) and semi-hard wood shots (August) to three plant growth regulators (PGRs), namely, IAA, IBA, and NAA applied at various concentrations (0, 100, 500, 1000, 2000, and 3000 mg/l) were examined in sand and mixed soil media. Percentage of rooting showed significant difference between cutting time, among kinds and among concentration of PGRs. The optimum cutting time was April to May in hardwood cutting. The application of IAA 1000 mg/l and NAA 500mg/l were effective in callus formation and rooting of cutting. Relatively, rooting of cutting of the control taken in May was above 93%.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.243-251
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• 2005

This study was carried out to evaluate precipitation, geological and topographical factors from the landslide area occurred in Maeri, Sangdong-myeon, Gimhaesi, Gyeongsangnam-do. The landslide was affected by geo-topographical factors. Talus which is infiltrated easily by runoff was widely distributed in the landslide area. Concave areas on back- and toe-slope were built up colluvial materials and weathered soils. The colluvial materials were consisted of less weathered pebbles and stones (diameter: 10~100 cm) which are easily infiltrated during rainfall events. Also the landslide was mainly affected by an ascending of ground water table which is low in summit and high in toe-slope due to geo-topographical characteristics of the landslide area. The most important reason of the landslide was a lacking of drainage system of ground water despite the high infiltration rates of ground water in talus area during rainfall events.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.251-257
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• 2001

This experiment was conducted to investigate the effect of chitosan on the growth and yield of fall-planted potatoes. The research was carried out in fall-planted potatoes from August 2000 to Aprial 2001 at the height of 250m above sea level in Jeju Island. Soaking for 30 min. of seed potatoes in 200 times diluted solution of 3% liquid chitosan shortened days to emergence by 4 to 6 days. Stem length, number of stems and number of stolons per plant were 56.5 cm, 4.3, and 19.0, respectively, when seed potatoes were soaked for 30 min. in 200 times diluted solution of 3% liquid chitossan. Total potato yield in this treatment reached 2,963 kg per 10a and was significantly greater than in other treatments. Yield of marketable tubers (greater than 30g) per 10a for treatment of seed potatoes soaking in 200 times diluted solution of 3% liquid chitosan and for treatment of foliage spray with 200 times diluted solution of 3% liquid chitosan plus chitosna power (10 kg per 10a) miximg with soil was 2,761 kg and 2,628 kg, respectively. Contents of Mg, Fe and B were the greatest in the treatment of 30 min. soaking of seed potatoes in 200 times diluted solution of 3% liquid chitosanm. The increased contents of these elements are considered to have caused yield increase as a result of increased chlorophyll content for photosynthesis.

• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.1-7
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• 2001

This experiment was carried out to investigate the effects of shading treatments and harvesting methods on the growth of Eleutherococcus senticosus, which was known as the medicine of anticancer, anti-stress, hepatic detoxification activity, immunoactivity, and tonic. Light transmission ratio and air temperature were decreased as $40{\sim}64%$,$1.9{\sim}2^{\circ}C$, respectively, in 30% to 70% shading net treatment compared to non-shading. Fifty percentage shading net treatment was effective for the growth and yield of Eleutherococcus senticosus. During summer Eleutherococcus senticosus was growing under shading net treatment compared to non-shading. Tunnel type was more effective for growth than vertical type in shading method. 30cm length included 2 to 3 nodes cutting from soil surface was the most effective for branching stem length, plant height and yield as harvesting methods.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.80-89
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• 2017

Researches about NPS(Non-point Pollution Source) reduction have been widely carried out in recent years. A pilot channel-type constructed wetland (wet swale) was constructed in Rongyin area to treat stormwater generated from a green house agro-land of 22.7 ha. From 2006 to 2008, monitoring was conducted to evaluate its performance on the removal effect for organic pollutants as well as nutrients. Totally, sampling trips of 17 rainfall events were made and they covered most types of storm events in Korea. The channel-type constructed wetland have average removal efficiencies of 78.3~92.0%, 56.4~66.1%, 28.2~45.5% and 50.6~66.4% for SS, COD, TN and TP, respectively. According to four methods for estimating the removal efficiency, the average efficiencies of TSS, COD, TN and TP are 86.0%, 60.1%, 30.1% and 53.5%, respectively. From 2006 to 2008, annual efficiency improved due to infiltration potential increase. It was found that most of the pollutants removed in this channel type of wetland was particulate solids bound pollutants, which is assumed fact that it lacks of physico-chemical treatment conditions which are commonly observed in the retention type of constructed wetlands.

• Research in Plant Disease
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• v.14 no.3
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• pp.210-213
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• 2008

The occurrence of Rice stripe virus (RSV) has been confirmed in some parts of South Korea. In the current year, this was observed to be limited in the double cropping zones of the southern region. Earlier, RSV occurred largely in the west coast regions of the country, particularly in Gangwha, Gyeonggi-do in 2001; and Buan, Jeollabuk-do and Seocheon, Chungcheongnam-do in 2007. This study was carried out to determine the nationwide extent of RSV occurrence by investigating RSV infestations in different latitudes and altitudes. Result revealed a recent reported occurrence of RSV in the southern region (Milyang, latitude $35^{\circ}$), a reported occurrence in the northern region (Cheolwon, latitude $38^{\circ}$) in 2005, and in the middle northern region of the east coast (Goseon, latitude $38^{\circ}$) as newly confirmed from this investigation. Results also confirmed the occurrence of RSV in a wide range of altitude from the plains (Milyang, 17 m altitude) to the alpine regions (Jinbu, 576 m) including the middle mountains (Sangju, altitude 285 m). The RSV occurrence in Jinbu in the alpine region and at Goseong and most of the northern end regions were confirmed only this year. The results of the present study confirmed that RSV is a fast-spreading disease in rice plant cultivation regions of the entire country.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.97-105
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• 2009

It is expected that logistics standardization have an great effect on industry and national economy due to cost saving and improving efficiency. Therefore all countries of the world make a strenuous effort to take a lead of logistics standardization Despite such efforts of every country, our country remained a lukewarm attitude about logistics standardization. Especially, our country remained a lukewarm attitude about logistics standardization effect quantify. We have to suggest the necessity of standardization and the effect for carrying out logistics standard. So, this study performed literature review and case study for development of effect valuation method. Also, this study developed effect valuation standard for quantifiable standardization effect and drew the effect valuation standard model. First, the measure of preliminary effectiveness was chosen for MOE selection. As a results, vehicle load ratio, delivery cost, keeping space efficiency warehouse automation ratio, etc. were selected. Then, vehicle/truck load ratio, warehouse keeping efficiency, up unloading hour, packaging cost, consistency transportation ratio were chosen for MOE of pallet standardization.