• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.1
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• pp.51-56
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• 2013

From the time the product is manufactured until it is carried and ultimately used, the product is subjected to some form of handling and transportations. During this process, the product can be subjected to many potential hazards. One of them is the damage caused by shocks. In order to design a product-package system to protect the product, the peak acceleration or G force to the product that causes damage needs to be determined. When a corrugated fiberboard box loaded with products is dropped onto the ground, part of the energy acquired due to the action of the gravitational acceleration during the free fall is dissipated in the product and the package in various ways. The shock absorbing characteristics of the packaging cushion materials are presented as a family of cushion curves in which curves showing peak accelerations during impacts for a range of static loads are shown for several drop heights. The new method for determining the shock absorbing characteristics of cushioning materials for protective packaging has been described and demonstrated. It has been shown that cushion curves can be produced by combining the static compression and impact characteristics of the material. The dynamic factor was determined by the iterative least mean squares (ILMS) optimization technique in which the discrepancies between peak acceleration data predicted from the theoretical model and obtained from the impact tests are minimized. The approach enabled an efficient determination of cushion curves from a small number of experimental impact data.

• Journal of Korean Institute of Industrial Engineers
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• v.11 no.2
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• pp.29-37
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• 1985

This paper studies a production-inventory model which unifies the inventory problem of raw materials and the finished product for a single product manufacturing system. The integrated production-inventory model is formulated wth a nonlinear mixed integer programming problem. An algorithm is developed by utilizing the finite explicit enumeration method. The algorithm guarantees to generate an optimal policy for minimizing the total annual variable cost. A mumerical example involving 15 raw materials is given to illustrate the recommended solution procedure.

• Journal of Powder Materials
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• v.28 no.1
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• pp.13-19
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• 2021

Bulk graphite is manufactured using graphite scrap as the filler and phenolic resin as the binder. Graphite scrap, which is the by-product of processing the final graphite product, is pulverized and sieved by particle size. The relationship between the density and porosity is analyzed by measuring the mechanical properties of bulk graphite. The filler materials are sieved into mean particle sizes of 10.62, 23.38, 54.09, 84.29, and 126.64 ㎛. The bulk graphite density using the filler powder with a particle size of 54.09 ㎛ is 1.38 g/㎤, which is the highest value in this study. The compressive strength tends to increase as the bulk graphite density increases. The highest compressive strength of 43.14 MPa is achieved with the 54.09 ㎛ powder. The highest flexural strength of 23.08 MPa is achieved using the 10.62 ㎛ powder, having the smallest average particle size. The compressive strength is affected by the density of bulk graphite, and the flexural strength is affected by the filler particle size of bulk graphite.

• Transactions of Materials Processing
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• v.32 no.6
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• pp.335-343
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• 2023

Spur Gear parts for automobile actuators using existing former forging technology were produced in a total of three processes on a former forging machine. However, in order to improve cost increase due to frequent mold breakage, Spur Gear parts were designed and manufactured in the cold forging process after forming the preform through former forging. In other words, in the existing former forging mold, product seating defects occurred due to horizontal movement, resulting in many product defects and mold damage, so there was an urgent need to improve mold life and product defects. In order to improve this, we tried to improve the mold life by improving the existing 3 former forging processes to a former forging process and 2 cold forging processes. Therefore, We developed Spur Gear parts for automobile actuators were developed by applying precision cold forging technology through a former forging process and 2 cold forging processes to improve mold life.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.1
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• pp.43-54
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• 2021

This work proposes a process to derive elements of emotional materials based on trend research in the application of materials in product development. It was intended to be applied to the development of a case model, a Korean sports wheelchair, and focused on the material portion of CMF-based research. Through research methodologies such as megatrends, competitor product and part-by-part analysis, and psychological color analysis, we studied optimization, verification, and DBization of materials, and drew the final application plan through FGI verification.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.1
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• pp.25-28
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• 2007

Physical damage on fruits and vegetables caused by shock degrades the value of product in the fresh market. In order to design a product/package system to protect the product, the peak acceleration or G force to the product that causes shock damage needs to be determined. Shock cushion packaging is applied to protect goods of all kinds. It can be adapted in their shape to any product to be packed, so that its shock absorbing properties is determined by geometry of the product. The shape of a cushion can be adapted to the expected shock loads. To analyze the response properties of cushion materials for packaging of the pears for optimum packaging design during transportation, shock tests were carried out. Shock acceleration that is happened in pears were appeared very high by $25{\sim}30G$ in the input shock acceleration of 14.1618 G that was measured in transportation road. This means that the pears receive the shock acceleration more than maximum double itself and the damage by this can happen and the shock acceleration increase in case use PE tray cup and PE net in fruits, the use of corrugated fiberboard pad may become one method that it can reduce the damage by the shock in packaging of fruits.

• Fisheries and Aquatic Sciences
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• v.22 no.1
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• pp.1.1-1.8
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• 2019

Five experimental diets were formulated to evaluate the effects of dietary enzymatically hydrolyzed tuna by-product on growth, non-specific immune responses, and hematology of juvenile rainbow trout (Oncorhynchus mykiss). A basal diet with 50% of fishmeal was used as control (CON) and four other diets replaced 12.5% ($TBB_{12.5}$), 25% ($TBB_{25}$), 37.5% ($TBB_{37.5}$), and 50% ($TBB_{50}$) of fish meal in the CON diet. Juvenile rainbow trout ($4.87{\pm}0.05g$) were randomly distributed into 15 tanks (50 L) and fed 3-4% of wet body weight two times a day. At the end of 7 weeks of feeding trial, weight gain, specific growth rate, feed efficiency, and protein efficiency ratio of fish fed CON diet were significantly higher than those of fish fed $TB_{50}$ diet (P < 0.05). But there were no significant differences among fish fed CON, $TBB_{12.5}$, $TBB_{25}$, and $TBB_{37.5}$ diets (P > 0.05). There were no significant differences in GPT levels among fish fed CON, $TBB_{12.5}$, $TBB_{25}$, and $TBB_{37.5}$ diets. Also, there were no significant differences in lysozyme, superoxide dismutase, glucose, and total protein levels in all experimental diet (P > 0.05). The broken-line analysis indicated that the minimum dietary level of enzymatically hydrolyzed tuna by-product to replace fishmeal could be 29.7% in rainbow trout. These results indicated that the optimum level of dietary enzymatically hydrolyzed tuna by-product could replace greater than 29.7% but less than 37.5% of fishmeal in juvenile rainbow trout diet.

• Journal of Power System Engineering
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• v.16 no.6
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• pp.59-65
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• 2012

Torque Generator is a product which has function to transform hydraulic energy to mechanical energy of torque and rotating speed, and be used for direction change device of agricultural machines. This study proposes failure analysis and test analysis on torque generator and introduces a process that reliability of a product is enhanced by design improvement. And also it presents improvements of maximum output torque by modifying design and surface treatment. Lastly it verifies reliability improvement by analyzing test results of before and after life test.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.3
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• pp.566-573
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• 2016

Sustainability in fashion cannot ignore fashion attributes required for the design of rapidly changing and innovative products. This study examines "Re-Birth Design" development and provides a means to apply academic and industry perspectives to the investigation of Re-Birth fashion product development. This study defines "Re-Birth Design" as stock that has been designed and launched through distribution channels, subsequently returned unused, then improved and reborn into a new product for redistribution. This study analyzed specific cases. We selected 100 designs for Re-Birth from 11 brands of "K" fashion company in Korea, to be successfully sold in 2014. These cases are used in the analysis and are categorized into design types. As a result of the analysis, "Re-Birth Design" had five levels: Level 1. Changes in supplementary materials such as adding or removing decoration, Level 2. Changes in patterns or materials (changes within the product), Level 3. Partial changes in design (leading to a new design), Level 4. Complete deconstruction and rebirth of the design, and Level 5. Complete deconstruction followed by the use of the design source for a new product that is not a garment. This study analyzed products owned by brands, as well as successful cases of Re-Birth designs that reused existing resources, reduced energy consumption, and increased environmental and economic efficiency by recreating new products that could be resold.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1652-1655
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• 2008

A new high contrast LCD structure for TN mode TFT-LCD, of which the contrast ratio is 1.2 times hi gher than that of the conventional one, has been developed. The contrast ratio of TFT-LCD display can be improved by some modified materials, which like as polarizer, liquid crystal, color filter and light enhancement film. In order to know which condition can get the major contribution for the upgrade of the contrast ratio, we used Taguchi method and analyzed the contribution ratio for each composition and succeed to build up the formula of contrast ratio. From this study, we could achieve the highest CR value as 1200:1 of TN mod e TFT-LCD nowadays.