• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.4
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• pp.71-77
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• 2010

To utilize modified pulp fibers in papermaking system, it is necessary to evaluate the interaction between modified fibers and papermaking additives. Fluorescent whitening agent (FWA) is an important additive which has been widely used for production of writing and printing paper. We modified pulp fiber surface by Layer-by-Layer multilayering of polyelectrolytes, and investigated the interaction between these fibers and FWA used in internal addition or surface treatment. Pulp fiber with cationic surface charge showed a good affinity to internal FWA. For FWA in surface sizing agent, whiteness and brightness of paper was dependent on pickup weight and polyelectrolyte type. Pulp fibers with C-starch/PSS multilayer showed better optical properties than poly-DADMAC/PSS treatment. It indicated that polyelectrolyte type in Layer-by-Layer multilayering as well as a good affinity to FWA is important to get better whiteness and brightness.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.22-28
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• 2012

We report a focal-length tunable liquid lens based on thermopneumatically driven fluidic pressure. The fluidic pressure is generated by deformation of an elastomeric diaphragm induced by thermopneumaticity from a laterally integrated microheater sealed within an air chamber. The pressure is transmitted by a confined liquid to a lens diaphragm through an internal fluid channel. The liquid filling under the lens diaphragm functions as a liquid lens for dynamic focusing with properties depending on the curvature of the deformed diaphragm. The diaphragm area of the air chamber is designed five times larger than that of the lens cavity to yield high focal-length tunability by amplified deflection of the lens diaphragm. With our method, we achieved excellent focal-length tunability from infinity (without an input current) to 4 mm (with an input current of 12 mA) with a lens aperture diameter of 2 mm.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.48-48
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• 2018

본 연구는 경남 함양군 삼봉산의 관속식물을 조사한 후 식물상 현황과 특정식물종 및 귀화식물 등을 정리하였으며, 차후 식물상의 보호 관리에 있어 기초 자료로 활용하고자 실시하였다. 삼봉산은 전북 남원시 산내면 중황리, 인월면 상우리와 경남 함양군 마천면 구양리, 함양읍, 죽림리가 접하는 지역으로 남쪽으로는 국립공원 지리산의 연봉이 길게 늘어서 있고 북쪽으로는 광주대구 고속도로 건너 함양군의 백운산과 괘관산 등 1,000m가 넘는 산이 많은 지역내에 위치하고 있다. 삼봉산지역에 자생하는 관속식물은 총 80개과 182개속 254개 종이 생육하는 것으로 나타났다. 삼봉산 지역의 특정식물종은 식물구계학적 특정식물 V등급인 승마 Cimicifuga heracleifolia Kom.)와 IV등급인 도깨비부채(Rodgersia podophylla A.Gray), 점현호색 (Corydalis maculata B.U.Oh & Y.S.Kim), 솔붓꽃 (Iris ruthenica KerGawl.), 산복사나무 [Prunus davidiana (Carriere) Franch.] 등이 분포하는 것으로 확인되었다. 조사결과 가흥지역에서 환경부 멸종위기종은에 해당하는 분류군은 없었으며 특정식물종 V등급에 해당되는 승마와 IV등급에 해당되는 4개 분류군이 확인되었다. 국립공원지리산 근처의 1,000m이상의 산지임에도 전체적으로 50년 전부터이루어진 조림과 능선 바로 아래까지 경작지가 존재하는 등 식생의 파괴가 심하여 전체적인 관속식물의 다양성은 낮은 것으로 확인되었다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.10
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• pp.710-717
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• 2007

Electric and telecommunication industries are constantly striving towards miniaturization of electronic devices. Miniaturization of chips creates extra space on PCBs that can be populated with additional components, which decreases the heat transfer surface area and generates very high heat flux. Even though an air-cooling technology for telecommunication equipment has been developed in accordance with rapid growth in electrical industry, it is confronted with the limitation of cooling capacity due to the rapid increase of heat density. In this study, liquid-cooling heat exchangers with MPCM slurries were designed and tested by varying geometry and operating conditions. The liquid-cooling heat exchangers with 4-paths showed higher cooling performance than the others. The cooling performance of liquid cooling heat exchanger with MPCM slurries was more enhanced than that of the air cooling system. It's performance was also slightly superior to that of the water cooling system at the inlet temperature of $19^{\circ}C$.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.02a
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• pp.109-112
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• 2008

본 논문에서는 MPEG-4 HE-AAC의 SBR 부호기의 효율을 개선하기 위해 예측 SBR(Predictive-SBR)을 제안한다. SBR 부호기는 주부호기(core encoder)와 결합하여 적은 비트량으로 고주파 성분을 복원할 수 있게 한다. 본 논문에서는 SBR 데이터의 약 70%를 차지하는 포락선 정보를 부호화하는 방법을 개선하여 효율성을 높이고자 한다. 기존 SBR은 포락선 정보의 전송을 위해 다음과 같은 방법을 이용한다. 먼저 고주파 대역의 에너지를 스케일팩터 밴드 단위로 계산한다. 다음으로, 전송정보량의 감소를 위해 델타 코딩 방식을 이용하여 에너지 정보를 부호화한다. 본 논문에서는 SBR의 포락선 정보를 효과적으로 감축하기 위하여 고주파 대역의 에너지를 예측하는 방법을 이용한다. SBR 부호기의 입력 데이터가 SBR 복호기의 입력데이터와 동일하다는 가정 하에 선형 회귀(linear-regression) 기법을 이용하여 고주파 대역의 에너지를 추정한다. 그 후에 추정된 에너지와 원래의 고주파 대역 에너지의 오차를 델타 코딩을 이용하여 부호화한다. 정보를 전송할 때는 고주파 대역 에너지의 델타 코드와 예측 SBR에서 계산한 오차의 델타 코드 중 부호화에 필요한 비트량이 적은 방식을 선택하여 부호화하도록 한다. 그 결과 약 10% 정도의 정보량 감축 효과를 얻을 수 있다.

• 한국해양학회지
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• v.10 no.2
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• pp.51-56
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• 1975

Continued to the previous papers, the present investigation is carried out to clarify cesium-137 activities and potassium contents among 54 samples of edible marine algae collected along the coast of Korea during September, 1973 and April, 1974. The potassium contents are variable, 1.5-29.6%, and 11.36% on an average, while most of the members contain them about 10-16% generally. Among the algal phyla, they are 13.49% in green, 10.82% in brown and 16.46% in red algae, respectively. Cesium-137 activities are variable, 0.19-8.13 pCi$\^$137/ Cs/g K, and 2.35 pCi$\^$137/Cs/g K on an average in the samples investigated. Among the algal phyla they are 4.35 in green, 2.17 in brown and 0.89 pCi $\^$137/Cs/g K in red algae, respectively. Green algae contain especially higher activities compared with the other two groups. The brown alga, Myelophycus caespitosus shows the highest activities, 8.13 pCi$\^$137/Cs/g K, among the members investigated. Considering the concentration factor, this plant would be an indicator plant of cesium-137 among the marine algae along the coast of Korea.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.116-123
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• 2006

During the last two decades, many researchers investigated influences of stress triaxiality on ductile fracture for various specimens and structures. With respect to a transferability issue, the local approach reflecting micro-mechanical specifics is one of effective methods to predict constraint effects. In this paper, the applicability of the local approach was examined through a series of finite element analyses incorporating modified GTN (Gurson-Tvergaard-Needleman) and Rousselier models as well as fracture toughness tests. To achieve this goal, fracture resistance (J-R) curves of several types of compact tension (CT) specimens with various crack length, with various thickness and with/without 20% side- grooves were estimated. Then. the constraint effects were examined by comparing the numerically estimated J-R curves with experimentally determined ones. The assessment results showed that the damage models might be used as useful tool for fracture toughness estimation and both the crack length and thickness effects should be considered for realistic structural integrity evaluation.

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.380-387
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• 2008

This paper presents a karaoke system employing a vocal region detection algorithm based on the vocal characteristics. In the proposed system, an input song is classified into vocal and instrumental regions using the vocal region detection algorithm. Then, a vocal removal method is applied only to the vocal region. To detect vocal region, a classification algorithm is designed based on the vocal characteristics in the TICFT (twice iterated composite Fourier transform) domain. For vocal removal, vocal components are extracted from a band pass filtered vocal region and they are subtracted from the original song, yielding a vocal removed song. The performance of the proposed method is measured on four different songs.

• Journal of the Korean Society of Costume
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• v.46
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• pp.31-48
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• 1999

The purpose of this study is to offer fundamental data for classification of somatotype for boys of elementary school age. The subject were 458 elementary school boys aged from 7 to 12 living in Pusan. Data were collected by 56 anthropometric 11 photoraphic measurements and 41 body indices. 56 anthropometric measurements were analyzed by ANOVA and method of Duncan-test as Multiple Range Test among 6 grade groups and then total 108 measurments were analyzed by statistical data processing. The results are as followings: 1, In Duncan-test boys were significantly different in most of height and length items but were not significantly different in main items for clothing construction among 1.2/3.4/5.6 grades so that the period of elementary school age were divided with 3 periods. 2. According to increase school age most of item's means increased gradually and personal difference for each items increased too. In case of height and length items the items of lower half were greater than the items of upper half in personal difference and depth items were greater than the breadth items in personal difference. And weight and angle items were very great personal difference is specially.

• Journal of Information Technology Services
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• v.11 no.sup
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• pp.41-50
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• 2012

With the recent advances in smart grid technologies and the increasing dissemination of smart meters, the power usage of each time unit can be detected in modern smart building environments. Thus, the utility company can adopt different price of electricity at each time slot considering the peak time. Korea government also announces the smart-grid roadmap that includes a law for realtime price of electricity. In this paper, we propose an efficient power scheduling scheme for smart buildings that adopt smart meters and real-time pricing of electricity. Our scheme dynamically changes the power mode of each consumer device according to the change of power rates. Specifically, we analyze the electricity demands and prices at each time, and then perform real-time power scheduling of consumer devices based on collaboration of each device. Experimental results show that the proposed scheme reduces the electricity charge of a smart building by up to 36.4%.