• Title/Summary/Keyword: Cycling Life

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Comparison between Color of Cycling Clothing Brands and Color Preference of Korean Consumers (국내외 자전거용 의류 전문 브랜드의 상품색과 한국 소비자의 의류 선호색 비교)

  • Jeong, Hoon Sil;Seo, Yea Ji;Choo, Sun Hyung;Kim, Young In
    • Journal of the Korean Society of Costume
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    • v.67 no.3
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    • pp.1-14
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    • 2017
  • Cycling has become a popular leisure activity, and many cycling enthusiasts have used cycling clothes as a form of expression, which often comes in wide range of colors. The study shows the importance of color in cycling clothing to meet the emotional needs of consumers. Furthermore, this study aims to provide comparative analysis between color of domestic and overseas cycling clothing brands, and color preference of Korean consumers in order to provide data, which can be used in satisfying consumers' needs for personal expression and emotional demands. Thus, the study expects to identify consumers' satisfaction for cycling clothing. The consumers were categorized by the frequency of cycling and their interest in fashion, and the following categories were made:potential consumers, casual cyclists with low fashion involvement, casual cyclists with high fashion involvement and frequent cyclists with high fashion involvement. Consumers preferred dark colors for their cycling clothing including jacket, top and pants, while 'frequent cyclists with high fashion involvement' preferred more diverse colors and tones. In the cycling clothing market, white and black were major colors, while red, orange and blue were major colors of chromatic color. In terms of shade, dark shade dominated the market. Comparing between preferred color and preferred product color, black was preferred for both, but no other colors showed such tendency. This study is based on empirical analysis and verification of color, which is the emotional element appealing to specific and segmented sports-apparel market. The study revealed that the data could be applicable to the design of future products.

Novel estimation method of operating life in lithium-ion pouch cells

  • Kim, Hyosung;Kim, Jaekwang;Kim, Nayeong;Lee, Ilbok;Hwang, Keebum;Bae, Joongho;Yoon, Songhun
    • Journal of Industrial and Engineering Chemistry
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    • v.67
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    • pp.266-275
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    • 2018
  • Herein, a novel operating life (OL) test method was evaluated with 200 mAh pouch-type lithium-ion batteries. By combining the calendar life (CL) test with intermediate pulse power cycling, more realistic life prediction was possible, which encompassed real operation of batteries accompanying with thermal acceleration. Larger capacity decrease and resistance increase of pouch cell were observed in the OL test, which was well explained using the SEI film growth model. After dissemble of pouch cell, capacity loss and resistance increase mostly occurred within anode, reflecting that SEI film growth on anode surface was highly attributable to cell degradation.

Verification Study of Lifetime Prediction Models for Pb-Based and Pb-Free Solders Used in Chip Resistor Assemblies Under Thermal Cycling (온도변화 환경에서 칩저항 실장용 유·무연솔더의 수명모델 검증연구)

  • Han, Changwoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.3
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    • pp.259-265
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    • 2016
  • Recently, life prediction models for Pb-based and Pb-free solders used in chip resistor assemblies under thermal cycling have been introduced. The models suggest that the field lifetimes of Pb-free solders would be better than those of Pb-based solders when used for chip resistors under thermal cycling conditions, while the lifetime of the chip assemblies under accelerated test conditions show a reverse relationship. In this study, the prediction models were verified by applying the model to another research case. Finite element models were built, thermal cycling conditions were applied, and the energy densities were calculated. Finally, life prediction analysis was conducted for the cases where Pb-based and Pb-free solders were used. The prediction results were then compared with the test data of the case. It was verified that the predictions of the developed life cycle models are on the practical scale.

A Study on Long-Term Cycling Performance by External Pressure Change for Pouch-Type Lithium Metal Batteries

  • Seong-Ju Sim;Bong-Soo Jin;Jun-Ho Park;Hyun-Soo Kim
    • Journal of Electrochemical Science and Technology
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    • v.15 no.2
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    • pp.314-320
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    • 2024
  • Lithium dendrite formation is one of the most significant problems with lithium metal batteries. The lithium dendrite reduces the lithium metal batteries' cycling life and safety. To apply consistent external pressure to a lithium metal pouch cell, we design a press jig in this study. External pressure creates dense lithium morphology by preventing lithium dendrite formation. After 300 cycles at 1 C, the cells with the external pressure perform far better than the cells without it, with a cycling retention of 97.8%. The formation of stable lithium metal is made possible by external pressure, which also enhances safety and cyclability.

Exploring the relationship between demographics of cycle tourists and the quality of life

  • Seo, Won-Jae;Jang, Joo-Young;Kim, Yong-Eun;Han, Seung-JIn
    • Journal of Sport and Applied Science
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    • v.2 no.1
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    • pp.25-38
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    • 2018
  • One of the largest and fastest growing segments of the tourism industry, sport tourism refers to travel to play sports, watch sports, or to visit a sport attraction including both competitive and non-competitive activities. In this respect, cycling can be considered as not only a form of physical exercise but also a form of tourism in which cycling is a usual tourism-related activity, heading to a particular destination. The purpose of this study is to examine how demographical differences of cycle tourists are related to the quality of their life. An online survey was conducted and data was analyzed using frequency, reliability, and one - way ANOVA using SPSS 22.0. First, we found that there was no significant difference on the quality of physical life based on demographical characteristics. Second, the analysis of the relationship between demographical characteristics and the quality of mental life showed that income level affects their quality of mental life. Third, the analysis of the relationship between socio demographic characteristics and the quality of social life showed that marital status affects the quality of social life. Fourth, no statistically significant difference was found between the demographical characteristics and the quality of environmental life. Further implications were discussed.

Effect of Temperature on the Deterioration of Graphite-Based Negative Electrodes during the Prolonged Cycling of Li-ion Batteries

  • Yang, Jin Hyeok;Hwang, Seong Ju;Chun, Seung Kyu;Kim, Ki Jae
    • Journal of Electrochemical Science and Technology
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    • v.13 no.2
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    • pp.208-212
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    • 2022
  • In this paper, we report the effects of temperature on the deterioration of graphite-based negative electrodes during the longterm cycling of lithium-ion batteries (LIBs). After cycling 75 Ah pouch-type LIB full cells at temperatures of 45℃ (45-Cell) and 25℃ (25-Cell) until their end of life, we expected to observe changes in the negative electrode according to the temperature. The thickness of the negative electrode of the cell was greater after cycling; that of the electrode of 45-Cell (144 ㎛) was greater than that of the electrode of 25-Cell (109 ㎛). Cross-sectional scanning electron microscopy analysis confirmed that by-products caused this increase in the thickness of the negative electrode. The by-products that formed on the surface of the negative electrode during cycling increased the surface resistance and decreased the electrical conductivity. Voltage profiles showed that the negative electrode of 25-Cell exhibited an 84.7% retention of the initial capacity, whereas that of 45-Cell showed only a 70.3% retention. The results of this study are expected to be relevant to future analyses of the deterioration characteristics of the negative electrode and battery deterioration mechanisms, and are also expected to provide basic data for advanced battery design.

Swelling and hydraulic characteristics of two grade bentonites under varying conditions for low-level radioactive waste repository design

  • Chih-Chung Chung;Guo-Liang Ren;I-Ting Chen;Che-Ju, Cuo;Hao-Chun Chang
    • Nuclear Engineering and Technology
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    • v.56 no.4
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    • pp.1385-1397
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    • 2024
  • Bentonite is a recommended material for the multiple barriers in the final disposal of low-level radioactive waste (LLW) to prevent groundwater intrusion and nuclear species migration. However, after drying-wetting cycling during the repository construction stage and ion exchange with the concrete barrier in the long-term repository, the bentonite mechanical behaviors, including swelling capacity and hydraulic conductivity, would be further influenced by the groundwater intrusion, resulting in radioactive leakage. To comprehensively examine the factors on the mechanical characteristics of bentonite, this study presented scenarios involving MX-80 and KV-1 bentonites subjected to drying-wetting cycling and accelerated ion migration. The experiments subsequently measured free swelling, swelling pressure, and hydraulic conductivity of bentonites with intrusions of seawater, high pH, and low pH solutions. The results indicated that the solutions caused a reduction in swelling volume and pressure, and an increase in hydraulic conductivity. Specifically, the swelling capability of bentonite with drying-wetting cycling in the seawater decreased significantly by 60%, while hydraulic conductivity increased by more than three times. Therefore, the study suggested minimizing drying-wetting cycling and preventing seawater intrusion, ensuring a long service life of the multiple barriers in the LLW repository.

Effects of the Plant Inquiry Instruction using Rapid-cycling Brassica rapa on the Change of Plant Concept of the Elementary School Students (속성배추를 이용한 식물 탐구 수업이 초등학생의 식물 개념 변화에 미치는 효과)

  • Lee, Myung-Sun;Kim, Sung-Ha
    • Journal of Korean Elementary Science Education
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    • v.28 no.3
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    • pp.277-291
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    • 2009
  • This study is intended to develop plant inquiry instruction using Rapid-cycling Brassica rapa (RcBr) whose life cycle is relatively short, and to apply it to the elementary science instruction of the 4th grader and examine their plant concept, science inquiry skills and science-related attitudes. The materials were consisted of laboratory manuals for the students as well as teachers' guide. By observing the life cycle of RcBr, students can experience the conceptual learning of the plant's life cycle. In addition, this study investigated the cause of change in science inquiry skills and science-related attitudes by interviewing 12 students. It has shown that plant inquiry instruction using RcBr has meaningful effects on students' understanding of the plant concept, improving students' science inquiry skills, and changing students' science-related attitudes. Students who showed improvement in science inquiry skills were able to answer questions regarding science knowledge correctly. And students whose science related attitudes were improved had a positive attitude on cultivating RcBr. Students told that RcBr was an interesting and good material to inquire plant. Because of its small size and its relatively short life cycle of RcBR, it should be a desirable plant material for the inquiry instruction which can give rise to useful and meaningful results for the elementary school students.

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Up-cycling Product Development for Daily Household Supplies Utilizing Used Jeans (폐기된 청바지를 활용한 생활용품 디자인 연구)

  • Ahn, In-Sook;Kim, Ho-Kyung
    • Journal of the Korean Society of Costume
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    • v.65 no.1
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    • pp.76-88
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    • 2015
  • Excessive spending and the ever-changing fashion trends lead to an increase in material production to meet consumers' needs, which also in turn, increase the amount of industrial waste and many harmful pollutants. To address this problem, this study aimed to utilize discarded jeans' parts, reconstructing them into edgy and functional designs for everyday products. Six pairs of discarded jeans were collected and were used to create six types of functional products -three types of baskets, a bag, a slipper, and a key-holder. The benefits of up-cycling outweigh recycling because it not only increases the recycling rate, but also decreases the amount of energy and cost, thereby increasing the efficiency in recreating new innovative products. These proposed up-cycling ideas will serve as a great alternative for consumers to actively participate in reducing carbon emission, water usage, and waste to landfill by utilizing used clothing. This will guide how consumers can extend the life of their used clothing, utilize recyclable items more thoroughly, and keep used clothing out of landfills.