• Journal of agriculture & life science
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• v.51 no.1
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• pp.57-67
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• 2017

We conducted this study to investigate vegetation structure and soil conditions of six Viburnum erosum Thunb.(V. erosum) populations which showed high dominance. A total of 68 woody plants were observed to distribute: 13 in tree layer; 38 in subtree layer; and 48 in shrub layer. Based on the Mean Importance Value(MIV), the dominant tree species in the V. erosum populations were as follows in order of: Acer pseudosieboldianum(Pax) Kom., Callicarpa japonica Thunb., Indigofera kirilowii Maxim. ex Palib., Lindera obtusiloba Blume, Prunus sargentii Rehder, Quercus variabilis Blume, Rhododendron mucronulatum Turcz. and Vaccinium oldhamii Miq. In paticular, the species observed in all of the study sites were Quercus serrata Murray and Styrax japonicus Siebold & Zucc. It was found that the presence of V. erosum was positively correlated with that of Albizia julibrissin Durazz. and Symplocos chinensis f. pilosa (Nakai) Ohwi, while negatively correlated with that of Platycarya strobilacea Siebold & Zucc. According to the result, means of species diversity(H'), maxim species diversity(H' max), evenness(J') and dominance(1-J') were measured at 0.887, 1.102, 0.803, and 0.196, respectively. The soil conditions properties of pH value, organic matter content, total nitrogen content, and the amount of available phosphorous indices in the study sites were 4.3, 10.6%, 0.34% and $0.68mg{\cdot}kg^{-1}$, respectively. Meanwhile, the total amount of exchangeable cations of $Ca^{2+}$, $K^+$, and $Mg^{2+}$ were $16.84cmol_c{\cdot}kg^{-1}$, $6.41cmol_c{\cdot}kg^{-1}$, and $4.26cmol_c{\cdot}kg^{-1}$, respectively. Overall, Viburnum erosum Thunb. populations tend to grow in the strongly acid soil, which has great abundance of soil organic matters, a lot of exchangeable cations, and has higher amount available phosphorous than that of nitrogen.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.116.1-116.1
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• 2010

저급 연료원인 오일샌드는 아스팔트와 같은 중질유를 10% 이상 함유한 모래 또는 사암으로서, 겉으로는 시커먼 흙이나 모래처럼 보이나 내부에는 bitumen, 모래(점토) 및 물 등이 광물질 70~80%, bitumen 10~18%, 물 3~5% 정도의 비율로 혼합되어 있는데, 가열 또는 용매 추출 방식으로 오일샌드에 포함되어 있는 bitumen을 분리하여 정제하면 원유를 생산할 수 있으므로 고유가 시대의 대체에너지원으로 세계적인 석유회사들이 개발을 진행하고 있다. 따라서, 본 연구에서는 이러한 저급 연료원인 오일샌드 bitumen의 활용기술 개발을 위하여 기초특성 분석 결과 bitumen과 가장 유사한 특성을 가지는 것으로 파악된 중질잔사유를 대상으로 가스화를 통한 액체연료 전환을 위해 고점도 시료공급장치, 가스화기, 집진장치, 탈황장치, 수성가스 전환장치, 합성가스 압축장치, DME 전환장치 등으로 구성되는 시스템을 구축한 후 시험을 진행하였다.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.185-195
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• 2003

Phytoseiid mites are important predators of spider mites, rust mites and many of insect pests as well. From two-year (2001-2002) survey of apple orchards in Kyoungbuk and Suwon area, 13 species of phytoseiids, 12 species of the genus Amblyseius and one species of the genus Typhlodromus were found. Among them, Amblyseius womersleyi was the most dominant followed by A. rademacheri, A. orientalis, and A. makuwa. Amblyseius rademacheri and A. makuwa were mainly found from ground vegetation. Keys to genera and species were presented with some pictorial details and ecological notes of each species. Further discussion on systematics of the family Phytoseiidae and use in apple IPM were suggested.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.378-381
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• 2001

In the batch culture experiments, the addition of $MnSO_4$, was examined in flask culture, and then the optimal amounts of $MnSO_4$ was investigated in 2.5- L jar-fermenter. As a results, 0.005% $MnSO_4$ was found to enhance the ARA yield of 1.14- fold. Also the addition of $KH_2PO_4_4$ was investigated in 2.5-L jar-fermenter and the ARA yield was enhanced 1.20-fold. Fed batch culture study shown a relatively high productivity of cell mass (62.1 g/L) and ARA content (12.0 g/L) when 14% ammonia solution were alternatively used to control the pH and nitrogen source in the cultivation period.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.4
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• pp.549-559
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• 1999

An experimental study was peformed to measure the viscosity of microencapsulated PCM slurries as the functions of its concentration and temperature, and also influence to its fluid dynamics. For the viscosity measurement, a rotary type viscometer, which was equipped with temperature control system, was adopted. The slurry was mixed with water and Sodium Lauryl Sulphate as a surfactant by which its suspended particles were dispersed well without the segregation of particles during the experiment. The viscosity was increased as the concentration of MicroPCM particle added. The surfactant increased 5% of the viscosity over the working fluid without particles. Experiments were proceeded by changing parameters such as PCM particles'concentration as well as the temperature of working fluid. As a result, a model to the functions of temperature for the working fluid and its particle concentration is proposed. The proposed model, for which its standard deviation shows 0.8068, is agreed well with the reference's data. The pressure drop was measured by U-tube manometer, and then the friction factor was obtained. It was noted that the pressure drop was not influenced by the state of PCM phase, that is solid or liquid in its core materials at their same concentration. On the other hand, it was described that the pressure drop of the slurry was much increased over the working fluid without particles. A friction factor was placed on a straight line in all working fluids of the laminar flow regardless of existing particles as we expected.

• Transactions of Materials Processing
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• v.23 no.1
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• pp.41-48
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• 2014

The light guide plate has become the major component for the backlight module in general information technology products (e.g. mobile phones, monitors, etc.). High speed injection molding has been adopted for thin walled LGP giving advantages such as weight, shape, size, and reduction in production costs. In the current study, the rheological characteristics of high liquidity plastic resin PC(HL8000) were measured using a capillary rheometer to improve the reliability of the numerical analysis for high speed injection molding. With the measured viscosity and PVT of PC(HL8000), numerical analysis of injection molding was conducted using the simulation software(Moldflow). Filling time and deflection were predicted and compared with those of traditional PC resins(H3000, H4000). The results show that PC(HL8000) has significantly different rheological characteristics during high speed injection molding. Hence proper properties of the resin should be used to improve the accuracy of numerical predictions.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.365-372
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• 2006

신제품 개발 과정에 있어 시장 요인과 기술 요인의 통합적 설계가 강조되면서 마케팅 영역(marketing domain)과 제조 영역(manufacturing domain)의 경계면(interface) 사이의 의견을 균형 있게 조정, 수렴해 주는 경계 시스템(interface system)에 대한 연구의 중요성이 커지고 있다. 본 연구에서는 이러한 배경을 토대로 각 영역(domain)에서 대표되는 신제품 파라미터 설계 방법인 컨조인트 분석과 다구찌 방법을 비교함으로써 두 영역의 신제품 개발 관점을 대비시키고 나아가 신제품 파라미터 설계를 위한 통합적 해결방안(integrated solution)을 제시한다. 그리고 도출된 방법론을 자동차 운전석 내부 설계 사례에 예시적으로 적용함으로써 유용성을 검증한다. 본 연구에서 제시된 방법론의 핵심적 특성과 차별적 의의는 기존의 연구들처럼 두 방법론을 선택하여 사용하는 것이 아니라 순차적으로 결합한 새로운 프로세스를 사용함으로 두 영역에서 발생하는 상충 관계(trade off)를 해결하여 고객의 효용도와 품질의 강건함이란 목적을 동시에 만족시키는 설계가 가능하다는데 있다. 나아가 신제품 개발 목표와 기업의 전략에 따라 분석의 순서와 설계수준의 크기를 조정할 수 있는 신축성을 확보할 수 있다는 점도 제시할 수 있다.

• Electrical & Electronic Materials
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• v.8 no.5
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• pp.587-593
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• 1995

Silicone oils used insulating substances exhibit the both of organic and inorganic properties, and it has many superior characteristics such as the high thermal resistance and low thermal oxidation level when compared to other insulation oils. In order to investigate the dielectric loss due to the increase of viscosity, silicone oils of viscosity 1, 2, 5[cSt] had been chosen as the specimen and experiment has been performed in the temperature range of -70[.deg. C] - 65[.deg. C] and frequency range of 30 - 1*10$\^$5/[Hz]. As a result, the linear decrease of loss at low frequency region in high temperature was due to the influence of applying frequency, whereas the increase of loss at high frequency region was contributed by electrode's resistance. And increasing viscosity, the activation energy increased from 3.77[kcal/mole] to 7.21[kcal/mole]. The dipole moment of specimen was become clear 1.48 - 2.26[debyel in high temperature region(5 - 65[.deg. C]) and 1.05 - 1.80[debye] in low temperature region (-70 - -25[.deg. C])respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.902-907
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• 2007

This study was carried out to find the effect of ${\gamma}$ -irradiation on the physical properties of alginic acid and ${\lambda}$-carrageenan solution. Alginic acid and ${\lambda}$-carrageenan aqueous solution were irradiated with $Co^{60}$ ${\gamma}$ -rays in dosages ranging from 3 to 100 kGy, and then the molecular weight, viscosity and color were measured. The molecular weight of alginic acid and ${\lambda}$-carrageenan solution were decreased as the ${\gamma}$ -irradiation dosage increased. In addition, the viscosity of irradiated alginic acid and ${\lambda}$-carrageenan solution were decreased depending upon the ${\gamma}$ -irradiation dosage, too. The high dosage irradiated alginic acid and ${\lambda}$-carrageenan solution's color were changed to yellow. These results suggest that low dosage of ${\gamma}$ -irradiation from 3 to 20 kGy is a very effective method for producing low-molecular alginic acid and ${\lambda}$-carrageenan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.175-187
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• 1997

Benthic community structure was studied in Chinhae Bay during 3 years from June 1987 to May 1990, based on the samples from 12 stations on the seasonal, bimonthly or monthly basis (lim and Hong, 1994a, b). A total of 287 species was sampled with mean density of $1045.5\;ind./m^2$ and biomass of $98.48g/m^2$ during studyperiods. Of these species, there were 91 species of crustaceans $(31.7\%)$, 88 of polychaetes $(30.7\%)$, 56 of molluscs $(19.5\%)$, 22 of echinoderms and 30 of the micellaneous species. Polychaetes were density-dominant faunal group with a density of $824.7\;ind./m^2$, comprising of $18.6\%$ of the total density of the benthic animals. It was followed by molluscs with $14.62\;ind./m^2$ $($14.4\%\;of\;the\;total\;density)$ crustaceans with $50.5\;ind/m^2\;(4.6\%)$ and echinoderms with $13.4\;ind/m^2\;(4.6\%)$. Molluscs were the biomass-dominant faunal group with a mean biomass of $54.62\;g/m^2$. It was followed by polychaetes with $21.74\;g/m^2$ and echinoderms with $6.66\;g/m^2$. Based on community analysis, species richness, diversity and evenness showed decreasing trends toward the inner bay from outer stations, whereas dominance showed increasing. The three most dominant species Lumbrineris longifolia, Paraprionospio pinnata and Theora fragilis had densities over $40\%$ of the total density of benthic organisms in Chinhae Bay. Seasonal changes of benthic communities in the inner bay were high compared to those of the outer bay. It was mainly due to the occurrence of hypoxic condition in the inner area of the bay. Cluster analysis showed that the benthic community could be divided into four stational groups, that is, Group 1, the innermost area, which received the most heavy anthropogenic effects including seawage and waste water, Group II, the central area of the bay, Group III, the transitional area, Group IV, the mouth pan of the bay exposed to the open sea. The areal groups based on the environmental factors coincided with the zonal groups from the species composition. This fact suggests that the overall spatial distribution of macrobenthos in Chinhae Bay was controlled by the sediment organic carbon content of the bay.