• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.11a
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• pp.1-12
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• 2001

In cold forging of piston-pin for automobile parts, the flow defect appears by the dead metal zone. This appearance evidently happens in products with a thin piercing thickness for the dimension accuracy and the decrease of material loss. The best method that can prevent flow defect is removing dead metal zone. The purpose of this study is to investigate the material flow behavior of forward-backward extruded piston-pin through the relative velocity ratio and the stroke control of upper moving punch & container using the flow control forming technique. The finite element simulations are applied to analyse the flow defect, then the results are compared with the plasticine model material experiments. Finally, the model experiment results are in good agreement with the FE simulation ones.

• Culinary science and hospitality research
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• v.6 no.3
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• pp.343-355
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• 2000

Caffeine is widely consumed ingredient and it belongs to alkaloids. Many foods that we intake contain caffeine ; coffee, tea cocoa, chocolate, and coke. And it is also added to many commercial remedies ; cold tablets, headache tablets, etc. Effect of caffeine that is known to us so far is as follows; 1. Remaining awake for long hours 2. Increasing concentration and decreasing fatigue 3. Increasing basal metabolic rate 4. decomposing glycogen and body fat and providing energy 5. Stimulating gastric acid 6. Increasing urinary excretion. Caffeine containing beverages(especially, coffee)are also favorite food in adult. In case of children and youth, chocolate and coke are favorite food. So, to intake caffeine containing foods moderately can be a vitality of life. But, a long-term intake or overdose of caffeine can result in many side effects. For example, headache, irritability, restlessness, hypertension, fetal abnormality, etc. Therefore, it is desirable that caffeine intake is under 300-400mg per day. To decrease intake of caffeine, 1. Use decaffeinated coffee 2. Product of decaffeinated coffee bean through gene transformation 3. Indicate content and function of caffeine on caffeine-food container 4. Provide an information of caffeine to public.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1366-1375
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• 2002

In cold forging of piston-pin for automobile parts, the flow defect appears by the dead metal zone. This appearance evidently happens in products with a thin piercing thickness for the dimension accuracy and the decrease of material loss. The best method that can prevent flow defect is removing dead metal zone. The purpose of this study is to investigate the material flow behavior of forward-backward extruded piston-pin through the relative velocity ratio and the stroke control of upper moving punch & container using the flow control forming technique. The finite element simulations are applied to analyse the flow defect, then the results are compared with the plasticine model material experiments. The model experiment results are in good agreement with the FE simulation ones.

• Clean Technology
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• v.22 no.1
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• pp.45-52
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• 2016

This study reports on the modeling and simulation of heat transfer in packaging boxes used for vaccine shipping. Both water and n-tetradecane are used as primary insulation materials inside a multi-slab system. The one-dimensional model, which is a spherical model using a radius equivalent to the rectangular geometry of container, is applied in this study. N-tetradecane with low thermal diffusivity and proper phase transition temperature exhibits higher heat transfer resistance during both heating and cooling processes compared to water. Thus, n-tetradecane is a better candidate as an insulating material for packaging containers for vaccine shipping. Furthermore, the developed method can also become a rapid and economic tool for screening appropriate phase change materials used as insulation materials with suitable properties in logistics applications.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2000.02a
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• pp.35-38
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• 2000

A preliminary design of gas-gp thermal switch is presented to reduce the cooldown time of superconducting system conduction-cooled by a two-stage refrigerator without liquid cryogens. The switch connects thermally the first and the second stages (ON) to take advantage of the larger refrigeration capacity at the first stage during the beginning period. After the cryogenic temperature is reached, the switch should isolate thermally the two stages (OFF) in order to reduce the heat leak to the cold end. In this paper, a new concept for the performance index is introduced to evaluate the reduction of the cooldown time and the increase of the cooling load at the same time. In addition, the design of a gas-gap switch is discussed as a closed container of several staggered concentric tubes filled with gas, which is frozen at low temperatures for the shut-off of heat without any mechanical actuation. Some of the detailed features in the design is quantitative investigated by the gas convection model in the continuum or the rarefied gas region.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.144-149
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• 1996

In this paper, the clamping type forging of helical gears has been investigated. Clamping type forging is an operation in which the product is constrained to extrude sideways through an orifice in the container wall. Punch is cylindrical shaped. The punch compresses a cylindrical billet placed in a die insert. As a consequence the material flows in a direction perpendicular to that of punch movement. The forging has been analysed by using the upper-bound method. A kinematically admissible velocity field has been developed, wherein, an involute curve has been introduced to represent tooth profile of the gear. Numerical calculations have been carried out to investigate the effects of various parameters, such as module, number of teeth, helix angle, friction factor and initial height of billet on the forging of helical gears.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.280-283
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• 2019

통신기술이 1 세에서 5 세대로 발전하는 동안 해상물류의 핵심인 컨테이너는 기능상의 큰 발전없이 과거에 머물러 있다. 이에 본 논문에서는 컨테이너의 위치 및 상태 정보를 수기로 관리하던 기존의 방식에서 벗어나 IoT 장비를 활용해 실시간 위치 파악, 상태 모니터링 및 자동화 등을 통해 물류의 가시성을 확보하고 컨테이너를 효율적으로 재배치함으로써 비용 절감 및 새로운 서비스 창출하기 위한 스마트 컨테이너를 제안한다. 부가적으로, 태양열판을 이용한 전원공급, 펠티어 소자를 이용한 냉방기능을 제공함으로써 신선 식품 배송의 핵심인 풀 코드 체인(Full Cold Chain) 플랫폼으로 활용범위를 넓히고자 한다.

• Asia-Pacific Journal of Business
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• v.9 no.3
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• pp.101-115
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• 2018

The purpose of this study is to examine the growth status and future prospects of the shipping industry over the past decade through a review of the statistical database and related literature. We classify the shipping industry and survey a number of companies, number of employees, sales trends and shipping logistics market outlook, port cargo volume, and container throughput trends with regard to the sea cargo shipping business, freezing cold warehousing business, harbor cargo unloading business, and international freight forwarding business. We will also look at the overall trends, scale, cargo volume, and harbor automation status of the global shipping market.

• Journal of Dairy Science and Biotechnology
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• v.35 no.2
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• pp.121-133
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• 2017

A small amount of milk is sold as 'untreated' or raw in the US; the two most commonly used heat-treatments for milk sold in retail markets are pasteurization (LTLT, low-temperature long time; HTST, high-temperature short time) and sterilization (UHT, ultra-high temperature). These treatments extend the shelf life of milk. The main purpose of heat treatment is to reduce pathogenic and perishable microbial populations, inactivate enzymes, and minimize chemical reactions and physical changes. Milk UHT processing combined with aseptic packaging has been introduced to produce shelf-stable products with less chemical damage than sterile milk in containers. Two basic principles of UHT treatment distinguish this method from in-container sterilization. First, for the same germicidal effect, HTST treatments (as in UHT) use less chemicals than cold-long treatment (as in in-container sterilization). This is because Q10, the relative change in the reaction rate with a temperature change of $10^{\circ}C$, is lower than the chemical change during bacterial killing. Based on Q10 values of 3 and 10, the chemical change at $145^{\circ}C$ for the same germicidal effect is only 2.7% at $115^{\circ}C$. The second principle is that the need to inactivate thermophilic bacterial spores (Bacillus cereus and Clostridium perfringens, etc.) determines the minimum time and temperature, while determining the maximum time and temperature at which undesirable chemical changes such as undesirable flavors, color changes, and vitamin breakdown should be minimized.

• Korean Journal of Medicinal Crop Science
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• v.24 no.5
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• pp.393-400
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• 2016

Background: This study was conducted to investigate the effects of germination temperature, storage container and storage temperature on Scrophularia buergeriana and Scrophularia takesimensis seeds. Methods and Results: Seed lengths of both species were 0.8 mm, while seed width differed, with S. buergeriana measuring 0.5 mm and S. takesimensis measuring 0.4 mm. The seeds of S. buergeriana were packaged in paper containers under room temperature ($15^{\circ}C$), cold temperature ($4^{\circ}C$), and freeze temperature ($-20^{\circ}C$). These seeds exhibited around 80% germination rate at temperatures between $15^{\circ}C$ and $30^{\circ}C$. The germiantion rate of S. takesimensis, on the other hand, differed significantly at different germination temperatures. Seeds of S. takesimensis which were packaged in vinyl and paper containers and stored under room and cold temperatures, exhibited around 80% germination rate at $15^{\circ}C$. However, the germination rate of freeze-stored seeds were decreased to lower than 20% at germination temperatures of $15^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$ germiantion conditions. The rate of germination showed a low positive to a significantly negativie correlation with the other factor that were determined to evaluate the germination performance. Conclusions: This study elucidates the most suitable germination and storage conditions to increase the germination rate for the two species of Scrophularia buergeriana and Scrophularia takesimensis needs to be stored in paper containers under cold temperature and requires a temperature of $20^{\circ}C$ for germination. On the other hand, S. takesimensis in vinyl containers need to be stored at room temperature and those in paper containers at cold temperature, and a temperature of $15^{\circ}C$ is required for germination.