• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.153-161
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• 2000

This study was carried out to examine the drift of Gammarus sobaegensis by acid stress as pH depression in Oweol creek from April 1996 to October 1996. The behavioral drifting was revealed to the characteristics of G. sobaegensis that is tend to increase as acid stress. And, tolerance level of G. sobaegensis to pH depression was different among the size classes. Individuals belong to small to medium size classes were weak in lower pH. Pattern of response in G. sobaegensis has a lower tolerance to acid stress at below pH 4.0 than above pH 5.0 in the artificial channel and show the possibility as an effective aquatic ecotoxicity test organism. The result of analysis of variance, water temperature (F-ratio : 66.596, p< 0.0005) and the size classes (F-ratio : 71.386, p< 0.0005) except pH level (F-ratio : 353.415, p<0.0005) were showed to the major factor for drift behavior by acid depression. [Gammarus, pH, Drift, Acid stress, Ecotoxicity test].

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.1
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• pp.29-36
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• 2009

In this paper, the design and implementation of LNA and down-mixer using 90 nm CMOS process are presented for 60 GHz band WPAN receiver. In order to extract characteristics of the transistor used to design each elements under the optimum bias conditions, the S-parameter of the manufactured cascode topology was measured and the effect of the RF pad was removed. Measured results of 3-stages cascode type LNA the gain of 25 dB and noise figure of 7 dB. Balanced type down-mixer with a balun at LO input port shows the conversion gain of 12.5 dB within IF frequency($8.5{\sim}11.5\;GHz$) and input PldB of -7 dBm. The size and power consumption of LNA and down-mixer are $0.8{\times}0.6\;mm^2$, 43 mW and $0.85{\times}0.85\;mm^2$, 1.2 mW, respectively.

• Journal of Advanced Navigation Technology
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• v.20 no.4
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• pp.344-351
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• 2016

In the present study, a dual-band multiple-input-multiple-output (MIMO) antenna covering WLAN frequency bands of 2.4 GHz (2.4 ~ 2.484 GHz) and 5 GHz (5.15 ~ 5.825 GHz) is newly presented to avoid use of decoupling structure for increasing isolation. The antenna consists of two L-shaped slots with n-shaped slots etched on the floating ground plane surrounded by open ended L-shaped slots which are placed in the left and right corner of PCB respectively. The proposed antenna is designed and fabricated on one side of FR4 substrate with dielectric constant of 4.3, thickness of 1.6 mm, and size of $50{\times}50mm2$. It has been observed that the measured impedance bandwidths ($S_{11}{\leq}-10dB$) are 0.3 GHz (2.28 ~ 2.58 GHz) in 2.4 GHz frequency band and 0.89 GHz (5.11 ~ 6 GHz) in 5 GHz frequency band respectively. In addition, It has been observed that the whole efficiency are more than 80 % in the whole operating frequency band and envelope correlation coefficient of the antenna is less than 0.05 as a very small value in spite of nothing of the decoupling structure.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.2
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• pp.103-116
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• 2017

In this paper, we present the design and implementation of a large-scale qualitative spatial reasoner, which can derive new qualitative spatial knowledge representing both topological and directional relationships between two arbitrary spatial objects in efficient way using Aparch Spark SQL. Apache Spark SQL is well known as a distributed parallel programming environment which provides both efficient join operations and query processing functions over a variety of data in Hadoop cluster computer systems. In our spatial reasoner, the overall reasoning process is divided into 6 jobs such as knowledge encoding, inverse reasoning, equal reasoning, transitive reasoning, relation refining, knowledge decoding, and then the execution order over the reasoning jobs is determined in consideration of both logical causal relationships and computational efficiency. The knowledge encoding job reduces the size of knowledge base to reason over by transforming the input knowledge of XML/RDF form into one of more precise form. Repeat of the transitive reasoning job and the relation refining job usually consumes most of computational time and storage for the overall reasoning process. In order to improve the jobs, our reasoner finds out the minimal disjunctive relations for qualitative spatial reasoning, and then, based upon them, it not only reduces the composition table to be used for the transitive reasoning job, but also optimizes the relation refining job. Through experiments using a large-scale benchmarking spatial knowledge base, the proposed reasoner showed high performance and scalability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.629-637
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• 2016

This study examined the purchasing behavior and satisfaction of people with convenience store PB foods. The factors affecting the purchasing behavior and the overall satisfaction with the convenience store PB foods were examined. This study first found that the purchasing motivation of PB foods is the cheaper price than NB foods. Second, age is a statistically effective variable for the visit frequency at the convenience store and gender and age are effective variables for the purchase frequency of PB foods. Third, there is a statistically positive correlation of convenience store brand preference with the PB food brand preference for 6 food categories. Next, in terms of the attribute-level satisfaction, the most satisfied areas are diverse food groups and diverse food taste and the least satisfied areas is price. This is followed by taste and design/packaging influence overall satisfaction. From this analysis, the following suggestions were drawn. First, because consumers are likely to be matched convenience store brand preference and PB food brand preference, advertising is necessary to ensure that the consumers continue to visit the convenience store. Second, product improvement by increasing the quality should be designed to motivate the major consumer group of people in their 20s and 30s. Finally, to boost PB food satisfaction, the industry should improve the taste and design/packaging.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.489-494
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• 1993

The amount of maize being imported from other countries to meet the national demand are increasing every year. Regardless of the usage whether it is for silage or for human consumption, amount of seeds for farmers are ever being increased. In order to solve the problems arising from the seed import, a program for developing waxy hybrids with high quality was set up at the College of Agr., Chungnam National University. The main breeding targets for high quality waxy hybrids are focused on the pericarp thickness. In order to obtain basic information needed for developing hybrids with thin pericarp, six inbred lines all derived from open pollinated Korean waxy lines were diallel crossed. Results obtained indicate that waxy hybrids with thin pericarp can be developed by choosing proper parental lines. Of the six inbreds, Jewon inbred had utmost thin pericarp compared with other lines. Hybrids crossed with Jewon showed also thinner pericarp than other hybrids. However, Danyang which has thick pericarp showed thicker pericarp in hybrid combinations. Variance due to general combining abilities was greater than the variance due to the specific combining abilities, indicating that additive gene effects are more important. The pericarp thickness of waxy hybrid endosperm varied with the parts of pericarp. The germinal side of the pericarp is comparatively thinner than the abgerminal side. The upper part (crown) has thicker pericaip than lower part (tip) of the kernel.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.173-176
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• 1996

정보통신기술은 현재 및 미래의 생활양식, 사회모습, 정치/경제/문화등에 이르기까지 모든 분양에 미치는 파급효과가 크기 때문에, 정보통신 기술개발에 관한 의사결정에 있어서는 기술 정책적인 고려가 반드시 필요하다. 그러나, 그 동안 정보통신 기술개발에 관한 의사결정에서 국가 차원의 정책적 고려가 매우 미흡하였다. 본 연구에서는 정보통신 분야에서의 기술정책에 대한 체계적 접근을 시도하였다. 본 연구의 결과는 세부분으로 구성되어 있다. 첫째, 정보통신 분야 기술정책의 체계를 제시하였다. 기존의 관련자료와 기술개발 전문가 및 정책 입안자들과의 면담을 거쳐 본 연구에서는 정보통신 기술정책에 포함되어야 할 주요내용을 1. 비전 및 우선순, 2. 산업조직및 하부구조, 3. 기술확보, 관리및 활용, 4. 정부 역할 및 정책 추진 기본 체계, 5. 국가 기술혁신시스템의 구축등 5개 부문으로 구분하고 각 부문별로 우리나라 정책현황과 문제점, 개선방안을 검토하였다. 둘째, 정보통신 기술개발에 관한 의사결정에서 고려해야 할 사항들을 정리하여 3단계 기술정책 수립모형을 개발하였다. 1단계에서는 검토대상사업이 정보통신 기술정책의 기본 지침과 일치하는지 확인하고, 2단계에서는 검토대상사업이 정보통신 기술정책의 내용상 우선순위에 부합하는지 검토한다. 3단계에서는 구체적인 기술정책지표에 의해 검토대상사업을 항목별로 검토하고 종합평가하여 최종의사결정을 한다. 여러 기술정책지표 항목들에 대해 가중치를 주어 평점모형(Scoring Model)을 통해 종합지표를 산출할 수도 있다. 셋째, 본 연구에서 제시한 3단계 기술정책 의사결정과정 모형을 CDMA 개발의 타당성을 검증하였다., (4) 교수-학생간의 인간적인 관계, (5) 숙제 및 과제물과 같은 5가지의 요인으로 구성되어진 것으로 분석되었다. 특히 한국학생을 대상으로 하여 AHP를 이용하여 각 요인들의 수업효과에 대한 상대적 가중치를 조사하였다. 특이한 결과는, 미국학생의 경우 수업준비 및 강의 방법이 상대적으로 중시된 반면, 한국학생들은 미국학생들이 비교적 덜 중시하는 교수-학생간의 인간적인 관계가 수업효과를 높이는데 가장 큰 기여를 하는 것으로 나타났다. 본 연구는 한국 문화의 특징이라 할 수 있는 교수-학생간의 인간적인 관계가 중시되는 교육환경하에서, 정보화 사회의 한 수업형태인 재택수업을 외국(특히 미국)의 방법을 그대로 따라 실시할 경우, 많은 부작용이 있을 수 있다는 것을 암시하며, 따라서 우리 교육문화에 맞는 재택수업 형태의 개발이 시급함을 제시한다고 하겠다.column density of HCaN is (1-3):n1014cm-2. Column density at distant position from MD5 is larger than that in the (:entral region. We have deduced that this hot-core has a mass of 10sR1 which i:s about an order of magnitude larger those obtained by previous studies.previous studies.업순서들의 상관관계를 고려하여 보다 개선된 해를 구하기 위한 연구가 요구된다. 또한, 준비작업비용을 발생시키는 작업장의 작업순서결정에 대해서도 연구를 행하여, 보완작업비용과 준비비용을 고려한 GMMAL 작업순서문

• Applied Biological Chemistry
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• v.36 no.6
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• pp.434-439
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• 1993

To investigate the effects of neutral salts on the foaming properties of sodium caseinate, turbidity, surface tension, absolute viscosity, foaming ability and foam stability of the caseinate solutions(5%, w/v) with added NaF, $Na_2SO_4$, NaCl, $NaNO_3$, and NaSCN at concentrations of 0.1, 0.5, 1.0, 1.5 and 2.0 M were examined. NaCl and $NaNO_3$ improved the foaming ability compared to sodium caseinate without salt, and also $Na_2SO_4$ and NaF did the foaming ability at the concentrations of 0.1M and 0.5M, while NaSCN did not improve the foaming ability. For foaming ability optimal concentrations of the salts were 0.5, 1.5, and 1.0 M in $Na_2SO_4$, NaCl, and NaSCN, respectively. Additions of $Na_2SO_4$, NaF and $NaNO_3$ at 0.5 M concentrations improved the foam stability of sodium caseinate by 825%, 615%, and 53% compared to control, while those of NaSCN reduced foam stability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.171-179
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• 2017

The purpose of this study was to examine the effect of the actor and partner effects of the parental sex-role attitude on the parent-child relationship by using the Actor-Partner Interdependence Model (APIM). Specifically, this study focused on the examination of the actor and partner effects of the parental sex-role attitude in married couples with immigrant women who have children under 5 years old. For the analyses, a total of 5,531 couples who participated in the National Survey on Multi-cultural Families were included and the major findings are as follows. First, the couple's sex-role attitude had a statistically significant actor effect on the parent-child relationship. Parents who were more conscious of gender equality displayed a better parent-child relationship and this effect was greater in the case of the father's attitude than the mother's. Second, the father's sex-role attitude had a statistically significant partner effect on the mother-child relationship, whereas the mother's attitude did not. Third, the couple's actor effects were greater than their partner effects and this means that the personal sex-role attitude has a greater impact on the parent-child relationship than the partners' attitude. The implication and limitations derived from these empirical-scientific database results and related studies in educational program of gender equality attitude for multi-cultural families.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.433-452
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• 2018

The shield tunneling method can minimize surface settlements by preventing the deformation of tunnel face and tunnel intrados due to tunnel excavation. For this purpose, it is very important to control the operating conditions of shield TBM. The face pressure and backfill pressure for tail void grouting should be the most important and immediate measure not only to restrain surface settlement, but also to influence the effective stress and pore water pressure around the circumstance of tunnel during excavation. The reaction of the ground to the application of face pressure and backfill pressure relies on the stiffness and permeability of ground. Especially, the reaction of saturated clayey ground formations, which shows the time-dependent deformation, is different from the permeable ground. Hence, in this paper it was investigated how the TBM operating conditions, ground stiffness, and permeability impact on the surface settlement of saturated clayey ground. For this purpose, a series of parametric studies were carried out by means of the stress-pore water pressure coupled FE analysis. The results show that the settlement of soft clayey ground is divided into the immediate settlement and consolidation settlement. Especially, the consolidation settlement depends on the ground stiffness and permeability. In addition, the existence of critical face pressure and backfill pressure was identified. The face pressure and backfill pressure above the critical value may cause an unexpected increase in the ground settlement.