• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.219-226
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• 2010

The stamping process is widely used in fabricating various sheet-parts for vehicle, airplane, and electronic devices due to its low processing cost and high productivity. Recently the use of thin sheets with corrugated structures has rapidly increased for the production of energy devices, e.g., heat exchangers and fuel cells. However, it is very difficult to make corrugated structures directly in the stamping process due to their geometrical complexity. To solve this problem, this paper proposes a multi-step stamping process with a combined heat treatment process: a sequence of the first stamping, heat treatment, and second stamping. By multi-stamping, we obtained successful results in fabricating very thin corrugated structures with thicknesses of $100{\mu}m$; these are applicable as part of a plate-type heat exchanger.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.148-154
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• 2001

The uplift capacity of a pile for improving the wind resistance of the 1-2 W type plastic film pipe on greenhouses was tested using the plane and corrugated piles with various shapes and diameters. First, the resistant uplift capacity was measured by using the uplift loading on plane piles. As the uplift loading on plane piles increased, the resistant uplift capacity also increased until the loading was reached to ultimate uplift capacity. After ultimate uplift capacity was appeared the uplift displacement, the uplift capacity was decreased gradually. Secondly, the resistant uplift capacity was measured by using the uplift loading on corrugated piles. After the uplift capacity was reached the uplift displacement, the uplift capacity was continually increased or decreased. In general, the ultimate uplift capacity was independent of pile shapes, pile diameter length, and embedded pipe depth. However, the ultimate uplift capacity of a corrugated pile was twice more than that of a plane pile without regard to its diameter and embedded depth. The ultimate uplift capacity per unit pile area was increasing in deeper embedded depth. However, the longer a pile diameter was, the less ultimate uplift capacity. The uplift capacity of a plane pile, used in conjunction with the design wind velocity (26.9m.s$^{-1}$ ) of the project area, was unsatisfiable without regard to diameters and embedded depths of piles, while most of corrugated piles were well appeared uplift capacity under various experimental conditions.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.5 s.118
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• pp.66-73
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• 2006

The effects of active packaging on the surface stiffness, mass, volume, density and weight changes of fresh as well as stored eggplant were studied at 11 and $25^{\circ}C$ for 10 days with active packaging material Type 1 and 2 and control. Mass, volume, and surface stiffness of eggplant decreased linearly throughout the storage period regardless of storage conditions; while the mass density showed a reverse trend in the ease of $11^{\circ}C$ storage. Reduction rate of mass, mass density and weight was observed minimum at $25^{\circ}C$ storage temperature with active packaging Type 1. The weight of eggplant decreased at a higher rate in the initial 4 days compared to that in the later period of storage regardless of storage temperature and type of packaging.

• Computational Structural Engineering
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• v.11 no.3
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• pp.165-172
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• 1998

본 연구에서는 종이 충격흡수의 효율적인 기하형상이 연구되었다. 일반적으로 충격흡수재는 골판지, 스폰지, 종이, 고무등으로 제작된다. 에너지 흡수거동에 대한 종이 충격 흡수재의 보강형태, 크기., 재료 특성에 대한 영향이 ABAQUS/Explicit5.5에 의한 유한요소 해석과 미끄럼 충격시험을 통해 연구되었다. 종이 충격 흡수재의 최대 변위는 충격속도에 따라 증가하며, 내부단수에 따라 감소하였다. 충격이력 특성은 내부단수가 7단일 때 5 msee까지 급속히 변형되며, 그 이후에는 영구변형으로 존재한다.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.4
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• pp.93-100
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• 2014

The packaging with environment-friendly materials become more important issue since the concern for the environment and the disposal of waste such as the packaging materials has increased. Although the paper based packaging such as corrugated box are widely used as a typical environment-friendly packaging stuff, the heat insulation properties of paper packaging did not get many attention. In this study, the heat insulation properties of paper were deeply evaluated to improve the functional properties as packaging material of the cold storage goods. The simple device for evaluating the heat insulation of paper product was developed. Subsequently, the changes in the heat insulation depending on the paper structure and the addition of the inorganic fillers were investigated by using the instrument. The higher basis weight and the less beating time resulted in the bulkier structure and the less efficiency of heat transfer. The addition of the perlite powder as a filler resulted in the great increase in the heat insulation, although the addition of the calcium carbonate decreased the heat insulation potential of paper.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.7
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• pp.706-712
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• 2004

This paper presents the design technique of output multiplexer(OMUX) for the Ka-band satellite transponder. Output multiplexer consists of low-pass filter(LPF), channel filter and manifold. Channel filters adopt dual-mode technique in design for mass and volume reduction and frequency response of channel filters is 4-pole elliptic response for high frequency selectivity. w-pass filters are designed to be of 13th order corrugated type for high rejection characteristic over reception band of satellite transponder. After initial design of channel filters and manifold, we optimized only a few design parameters for fast and easy optimization instead of optimizing all the design parameter. Measured results of a realized output umltiplexer for Ka-band satellite transponder show good agreement with the computed ones.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.3
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• pp.1-11
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• 2007

To evaluate the quality of waste paper used for the manufacture of linerboard, the types of papers and foreign materials in compressed waste paper currently used were investigated. The recycled fibers were obtained from printing paper, newspaper, wrapping paper, white coated paperboard and corrugated container. Their fibers were observed by using a microscope, and the mechanical properties of the recycled papers manufactured from the recycled fibers were investigated. The compressed wastepaper was composed of 54% paperboard, 20% printing paper, and 20% newsprint. The content of foreign materials was about 4%, showing higher contents compared to 1% of foreign substances provided by Korea paper manufacturers' association. The types of foreign materials were various, which include vinyls, plastics, metals, woods, styrofoams, and cloths. Sound fibers were generally observed in the recycled fibers of printing papers and wrapping paper. The recycled fibers of white coated board, corrugated container and newsprint showed to be generally damaged. The whiteness of each recycled fiber were highly affected by pulp bleaching and ink-particle mixing conditions. The values of breaking length and burst index were lower than those for corrugating medium and liner board specified in KS. Although the anatomical characteristics of recycled fibers varied, their strengths appeared to be similar. This result may be explained by the use of non-deinked fiber.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.3
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• pp.362-370
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• 1998

Absorption systems require a heat source for working but they have a great merit in that relatively low-temperature and low-quality types of thermal energy such as solar heat and exhaust heat can be effectively utilized as heat source. However details research related to absorbers which have a great effect on performances has been rarely done and thus there has been a strong hope for positive developments to improve their efficiencies. This paper describes absorption experiments made with different inside tube diameters and shapes. The purpose of this study is to acquire basic knowledge about heat and mass transfer in a falling film type absorber with vertical inner tubes. Heat and mass transfer were measured for water vapor absorption into a water/LiBr solution flowing down an absorber of vertical inner tubes. As a result absorption acceleration tube compares bare tube and heat transfer improved by order of insert spring tube corrugated tube grooved tube. And the acceleration that is good provided in inserting spring tube for both sides of heat and mass transfer.

• Journal of Power System Engineering
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• v.5 no.1
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• pp.35-43
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• 2001

Heat exchangers are called with important devices which have been widely used in industrial fields. Therefore, the design method for a heat exchanger is an important study in the aspect of energy saving. In this study, performance analyses for two types of plate and shell heat exchangers having a corrugated trapezoid shape of a chevron angle with $45^{\circ}$, were executed and compared with experiments. For this study, the operation liquids were adopted with non-phase changing water. In the analysis, ${\epsilon}-NTU$ method was used for a plate and shell heat exchanger and a program was constructed. Independent variables for a plate and shell heat exchanger are flow rate and inlet temperature. Compared with experimental data, the accuracy of the developed are ${\pm}2.5%\;and\;{\pm}5%$ at the type A and type B in the heat transfer rate, respectively. In the pressure drop, the accuracy of the proposed program for a plate and shell heat exchanger is within ${\pm}3%$ and 5% error bounds for the type A and type B, respectively.

• Korean Institute of Interior Design Journal
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• v.22 no.4
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• pp.94-103
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• 2013

This study investigated the windows and doors of traditional houses in Jecheon, designated as a cultural assets in Chungcheongbuk-do. It aimed to contribute to the study of korean traditional architecture by finding the characteristics of windows and doors, and to the preservation and reuse policy of local cultural assets. This study was conducted using the research methods of the literature and field survey, and it was to analyze and to compare the existing data and a current status. The result are as followings. Firstly, the windows and doors of kitchen in An-chae were generally installed double swinging type with wooden board door(板張門). Secondly, the windows and doors of An-bang were generally installed double swinging type with slender-ribbed windows and doors(細箭窓戶), were mostly installed Merum(遠音). Thirdly, the windows and doors of Daechung(大廳) towards the backyard were generally installed double swinging type with wooden board door, corrugated cardboard door(骨板門) and slender-ribbed windows. Lastly, the windows and doors of Sarang-bang in a house of nobility(班家) was installed triple windows and doors.