• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.12
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• pp.1380-1387
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• 2012

The transmit/receive(T/R) module is a key component in the active phased array system. The brick-type T/R module has been widely used and the miniaturization has been an important factor to get the flexibility of the system configuration. For the miniaturization, multi-function chips(MFC) having a common leg configuration are suitable to reduce the number of required MMICs and a high isolation between transmit and receive paths is necessary for the high gain T/R modules. In this work, we propose a bias timing scheme for the compact T/R module and show the optimum timing based on measurements, in order to improve the feed-back path loop problem and the consequent isolation problem of the common leg configuration. We have implemented high power(7 W/channel) and high T/R gain(35 dB transmit and 30 dB receive gains) within the half size($140{\times}80{\times}16mm^3$) of the conventional T/R modules.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.380-387
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• 2005

We report the performance of an open-frame type low-voltage high-current DC-DC converter module developed using an active clamp forward converter circuit and single ended rectifier. The converter module is designed with the specifications of an 3.3V output voltage, 30A output current, 100W output power and 36-75V input voltage. The synchronous rectifier is used to reduce the conduction loss at high current level and constant current control using precision PCB resistance is adapted to enhance the over current protection function in the system configuration. A prototype converter module is successfully implemented within 8mm height and quarter brick size (58x37mm) and recorded an $95W/in^3$ power density, 90.6$\%$ efficiency and 0.07$\%$ voltage regulation for the entire Input voltage range, thereby demonstrating its application potentials to future telecommunication electronics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5789-5794
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• 2015

Recently, thin and light-weight production technologies are needed in IT industry in accordance with increase of the smart phones and mobile PC products. In order to make light and high rigidity products, engineering plastic and aluminum materials are frequently used in products appearance and frame hat support structure. Especially aluminum extrusion and CNC Brick processes are widely used for high strength and high rigidity technology. But extrusion method has constraints to apply exterior design and CNC Brick process has relatively high production cost and low speed of manufacturing. In this research, a new process method is introduced in order to reduce material cost and to improve manufacturing speed dramatically. Plate forging process means basically that thickening of local wall area thickness after deform exterior shape by deep drawing and bending process. Therefore, it is possible to minimize the waste of material and the manufacturing time. In this study the process of plate forging is designed using finite element program AFDEX-2D and the thickness and the width of initial deformed blank. And it is verified as a sample which is a part of laptop developed through the proposed plate forging method.

• Earthquakes and Structures
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• v.22 no.2
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• pp.121-135
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• 2022

Many public buildings such as schools, hospitals, etc., where partial infill walls are present in reinforced concrete (RC) structures, have undergone undesirable damage/failure attributed to captive column effect during a moderate to severe earthquake shaking. Often, the situation gets worsened when these RC frames are non-ductile in nature, thus reducing the deformable capability of the frame. Also, in many parts of the Indian subcontinent, it is mandatory to use fly-ash bricks for construction so as to reduce the burden on the disposal of fly-ash produced at thermal power plants. In some scenario, when the non-ductile RC frame, partially infilled by fly-ash bricks, suffers major structural damage, the challenge remains on how to retrofit and restore it. Thus, in this study, two full-scale one-bay, one-story non-ductile RC frame models, namely, bare frame and RC partially infilled frame with fly-ash bricks in 50% of its opening area are considered. In the previous experiments, these models were subjected to slow-cyclic displacement-controlled loading to replicate damage due to a moderate earthquake. Now, in this study these damaged frames were retrofitted and an experimental investigation was performed on the retrofitted specimens to examine the effectiveness of the proposed retrofitting scheme. A hybrid retrofitting technique combining epoxy injection grouting with an innovative and easy-to-implement steel jacketing technique was proposed. This proposed retrofitting method has ensured proper confinement of damaged concrete. The retrofitted models were subjected to the same slow cyclic displacement-controlled loading which was used to damage the frames. The experimental study concluded that the hybrid retrofitting technique was quite effective in enhancing and regaining various seismic performance parameters such as, lateral strength and lateral stiffness of partially fly-ash brick infilled RC frame. Thus, the steel jacketing retrofitting scheme along with the epoxy injection grouting can be relied on for possible repair of the structural members which are damaged due to the captive column effect during the seismic shaking.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.441-448
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• 2023

Penicillium spp. are frequently found in meju, a Korean traditional fermented soybean brick. We isolated and identified 96 Penicillium spp. from 22 traditional meju, and their β-tubulin genes were sequenced for the genetic and taxonomic study. Penicillium Section Viridicata was the most commonly isolated group. Notably, we also isolated and identified Penicillium roqueforti, a crucial industrial strain employed in the fermentation of blue cheese. Additionally, certain strains exhibited relatively high protease and γ-glutamyl transpeptidase activities, suggesting that they might contribute to the development of kokumi flavor during meju fermentation. Interestingly, all eight Penicillium spp., including P. roqueforti, were found to possess both types of MAT1 genes. This intriguing finding suggests the feasibility of strain improvement through mating, thereby offering opportunities for industrial applications. Therefore, these studies pave the way for a deeper exploration of Penicillium's role in meju fermentation, potentially leading to the development of starters for producing plant-based cheese-flavored condiments.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.178-185
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• 2000

A set of tests were accomplished in order to get better insight of the basic material properties of masonry made of normal concrete brick and different type of mortar compositions. Three different types of test were performed. Masonry unit and prism were tested by compressive strength test, Masonry wallets were tested by compressive strength test. Masonry wallets were tested in diagonally under tension. A significant influence of different mortar compositions on compression strength of masonry prism was observed, The tests have shown that for diagonal compression three different mode of failure were possible : tension crack along the loaded diagonal sliding along a mortar joint and combined sliding and diagonal crack according to the adhesive strength of a mortar.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.341-345
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• 2006

zArchitect Kim lung-up used free-curved lines as his architectural language. We can categorize his language into 'overlapped curved lines' and 'juxtaposed circles.' We found that his language was expressed well when he applied a specific material, for example, overlapped curved lines - concrete and juxtaposed circles - brick. Furthermore, using the plasticity of concrete, he built roofs and columns in a curved form. He also created reliefs on the walls out of the characteristics of bricks. It can be evidence that he considered forms and characteristics of materials to design buildings. This research mainly focuses on his design method to use free-curved lines with specific materials based on the analyses of forms and materials applied in his architecture buildings and art works

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.293-298
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• 2002

Recycling of coal combustion by-product(Ash) are becoming more improtant in the utilization business as a result of the increased use of NOx reduction technologies at coal-fired power plants. current disposal methods of these by-products create not only a loss of profit for the power industry, but also environmental concerns that breed negative public opinion. This research made concrete crecast block using coal ash artificial aggregate for environmental-friendly products and compared strength special quality of this block with existent common use brick and analyzed application possibility in situ with a reserve experiment that measured strength property and manufactured method to handle coal ash produced in Bo-ryung thermoelectric power plant.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.437-439
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• 2002

Tangible user interfaces have attracted strong attention in the HCI(Human and Computer Interface) community for their ability to take advantage of skills humans develop in the real world. We are developing "tangible media aided design system" which employs physical objects i.e., brick as interfacing media for 3D graphic modeling. This system is targeting for persons who are afraid of experiencing 3D graphic modeling and virtual space, or have a sense of reluctance in approaching to them. Our approach suggests the easiest way for people to experience computer system and virtual space carefree while developing and improving their space sense. This work is one of initial explorations of media aided design system using tangible user interfaces.

• Proceedings of the Costume Culture Conference
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• 2000.09b
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• pp.1-10
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• 2000

최근 우리나라에서도 인터넷 사용인구가 1000만 명을 넘고 인터넷 비지니스에 대한 일반인과 기업들의 관심이 본격화되고 있다. 이처럼 인터넷 비지니스가 활발하게 전개되면서, 인터넷 비즈니스의 고객만족과 이를 위한 고객지향 마케팅 활동이 중요시되게 되었다. 즉 인터넷을 이용하여 어떻게 하면 고객만족을 달성할 수 있으며, 또한 인터넷 비즈니스에 적합한 마케팅 전략을 어떻게 수립할 수 있는가가 인터넷 비즈니스의 경영자에게 중요한문제로 제기되고 있다. 인터넷 비즈니스에서는 오프라인의 전통적인 기업(블릭 앤 모터:Brick and Motar)보다 고객만족이 훨씬 중요하다. 이처럼 중요한 고객 만족 수준을 높이기 위하여는 마케팅 활동이 고객지향 관점에서 이루어져야 한다. 따라서 본 논문에서는 인터넷 비즈니스의 마케팅이 고객지향 관점에서 어떻게 이루어져야 하는가를 마케팅의 기본과정에 따라 살펴본다. 구체적으로 본 논문은 인터넷 비즈니스의 특성과 성공요인, 인터넷 마케팅과 전통적 마케팅의 차이, 인터넷 비즈니스의 시장 세분화 및 표적 고객 선정, 그리고 인터넷 비즈니스의 마케팅 믹스 전략을 고객지향 관점에서 살펴본다. 그리고 마지막 장에는 인터넷 비즈니스의 고객지향 마케팅을 패션 비즈니스에 적용하여 인터넷 비즈니스의 앞으로 나아갈 방향을 제시해 본다.