• Journal of the Korean Geotechnical Society
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• v.18 no.6
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• pp.83-101
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• 2002

Elastic waves provide an important information about the soil mass in the near-surface. Soil properties in relation to elastic wave parameters are clarified to facilitate the application of geophysical technique to soil characterization. As an example, experiments are performed to gain further insight into the behavior of unsaturated particulate materials using bender elements. The small strain stiffness is continuously measured on specimens subjected to drying, and changes in stiffness are related to changes in interparticle forces such as capillarity, bonding due to ion sharing, buttress effect due to fine migration, and cementation due to salt precipitation. The rate of menisci regeneration is studied after a perturbation as well. Finally, several phenomena associated with the evolution of capillary forces during drying are identified.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.555-560
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• 2000

Anthocyanin pigments of purple-fleshed sweet potato (Ipomoea batatas) were extracted with methanol containing 1% HCL and purified with Amberlite IRC-50 cation exchange resin column chromatography. ndividual pigments were isolated by paper chromatography. Among the four bands obtained by paper chromatography, three major bands were identified to be pure pigments by HPLC system. Two pigments were identified through the analysis of acyl moiety, sugar moiety, alkaline degradation products of aglycone, Rf value of paper chromatogram and retention time of HPLC. The anthocyanin pigments of purple-fleshed weet potato seemed to be composed of peonidin-3-diglucoside-5-glucoside acylated with caffeic or ferulic acids.

• Magazine of the Korean Society of Agricultural Engineers
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• v.25 no.4
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• pp.12-17
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• 1983

20년전(年前)에 모로코에서 경지정리(耕地整理)와 관개조직(灌漑組織)의 배치(配置)에 관(關)한 모델이 개발(開發)되어 널리 사용(使用)되고 있다. '합리적(合理的) 배치법(配置法)'이라고 이름이 붙은 이 방법(方法)은 토지소유규모(土地所有規模)가 영세(零細)하고 여러가지 밭작물(作物)을 재배(栽培)하는 지역(地域)에서 현대적(現代的)인 농사법(農事法)과 윤환급수(輪環給水)를 하는데 적합(適合)한 방법(方法)이다. '합리적(合理的) 배치법(配置法)'은 다음 두가지의 다른 관개배치법(灌漑配置法)을 결합(結合)시킨 것이다. (1) 현대적(現代的) 집단농사(集團農事), 특(特)히 집단(集團) 경운(耕耘)을 주(主)로 한 농경기술자적(農耕技術者的)인 방법(方法), (2) 관개수로(灌漑水路), 배수로(排水路), 농도등(農道等)을 포함(包含)한 영구적(永久的) 포장관개조직(圃場灌漑組織)을 가진 관개공학기술자적(灌漑工學技術者的)인 방법(方法). 합리적(合理的) 배치법(配置法)은 분산(分散)된 여러개의 작은 필지를 통합(統合)하여 관개(灌漑)에 적합(適合)한 크기로 만드는데 관계(關係)되는 여러가지 요인(要因)을 다루어야 하며 필지의 크기, 지표(地表) 또는 스프링클러등의 관개방법, 작물(作物)의 종류(種類), 윤작(輪作), 농업(農業)의 기계화등(機械化等)이 이에 속(屬)한다. 이 방법(方法)을 적용(適用)한 지구(地區)에서 나타난 이점(利點)으로는 관개효율(灌漑效率)의 증가(增加), 수량(收量)의 증가(增加), 토지이용률(土地利用率)의 증가(增加), 현대적(現代的) 농사법(農事法)의 적용(適用) 증가등(增加等)이 있다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.6
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• pp.528-537
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• 2002

In this paper, the extended FDTD is used for the analysis of microwave circuits including active elements. Lumped elements such as R, L, C which are inserted into a microstrip line are analyzed with the FDTD lumped element modeling. Parasitic capacitance and inductance could be obtained using network modeling and so it is sure that FDTD lumped element modeling makes it possible to get more accurate data which include parasite components. Moreover, a balanced mixer using two diodes that are modeled by an extended FDTD is designed and the more exact characteristic of the mixer is acquired than in current circuit simulator.

• The Journal of Korean Academy of Prosthodontics
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• v.19 no.1
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• pp.61-73
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• 1981

The effects of the opaque porcelain firing temperature, the bonding agent and the degassing prior to the opaque firing On the bond strength were investigated by means of the tensile shear stIe$. The diffusional behaviours at the interface of the porcelain and the alloy, and .the microstructures of the ceramic and metal composite were studied for understanding the bonding mechanism. The results obtained in this experiment were summarizd as follow; 1. With no application of bonding agent, the tensile shear strength of the specimen firing at $1840^{\circ}F$ was higher than that of the specimen firing at $1760^{\circ}F$. 2. The highest bond strength was obtained by application of bonding agent without degassing prior to the opaque firing. 3. Application of bonding agent after the degassing showed the lowest bond strength. 4. The greater number of pores were observed at the firing temperature of $1840^{\circ}F$ than that of $1760^{\circ}F$ in the porcelain and the interface respectively.

• Journal of Haehwa Medicine
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• v.19 no.1
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• pp.1-7
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• 2010

Melasma is a common disorder that causes dark colored patches. It generally causes brown spots on the face, especially on the forehead, cheeks, and upper lips. The pattern of patches has bilateral symmetry in yellowish-brown to gray-brown colors. It is much more common in women than in men. Melasma is considered to be caused by environmental and physical constitutional factors and often occurs when a woman's hormone changes by pregnancy or the use of oral contraceptive pills. It is important to combine oriental medicine and Sasang constitutional medicine for treatment of Melasma. Normal treatment of Melasma includes warming oneself, removal of the emotional stress factors, and good nutrition.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.18-26
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• 1992

This paper describes a design model for conceptual design of ship. Existing design models have some problems. For example, operating environment of batch versions can not reflect design procedure of real world truely and reliability of results are not high because means of performance estimation are based only on empirical formula. To improve these problems of existing design models, a new design model has been developed. The new model consists of interactive environment with databases of main engine and existing ship data. To develop user-oriented system, graphic user interface(GUI) is adapted.

• Journal of Digital Convergence
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• v.17 no.12
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• pp.481-488
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• 2019

A change request in design education is a phenomenon manifested by changes in the value of the industry and market demands. Changes in external requirements and internal values that affect the design industry today are shifting from consumer-centered design to stakeholder-centered design. At the center of these changes, design education should be transformed into an educational mechanism that conforms to the characteristics of each field and design specialization should coincide with the direction of the capitalist market. Design specialization must realize the policy of education in economic value first, and should be changed to a design process that enhances rationality and efficiency from the previous apprenticeship education.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.3
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• pp.19-28
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• 2000

In general the data such as thrust, pressure, temperature and combustion time are measured in developing the propulsion system of solid rocket motor through static firing test. But in the case of personal surface to air missile there are required a severe safety specifications in order to eliminate gunner hazard from the exhaust plume of motors. The safety requirements lead to the design of separation device and safety igniter device. The dynamic firing test for the designed two devices should be conducted under the flight environmental conditions to verify the requirements compliance. In this study the technique for dynamic firing test of propulsion system of personal surface to air missile is proposed and the method to design the dynamic test bench is also studied.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1A
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• pp.18-26
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• 2009

Various relay technologies have been considered in wireless communication systems to enlarge the coverage and to enhance the system throughput. However, the coverage is limited by its modulation levels and additional time slot(s) is required for relaying. In the paper, by applying the hierarchical modulation to two-relay systems, two-hop relaying can be implemented instead of three hops, and both throughput and coverage can be enhanced. Throughout simulation analysis, the coverage extension is evaluated for different modulation levels and the total throughput is increased by up to two times.