• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.5 no.1
• /
• pp.73-83
• /
• 1993

Thermodynamic properties of alternatives for R12 and R22 were estimated and performances of refrigerating cycle using these refrigerants were compared. In this study, we adopt R134a, R22/R142b, R22/R152a, R22/R152a/R124 as alternatives for R12 and R32/R134a for R22. Thermodynamic properties of these refrigerants were estimated using modified CSD equation of state. Cycle simulations of the refrigerating system considering heat source were carried out in order to compare the performance of the system. R134a shows relatively lower COP than R12 but very similar VCR. R22/R142b(50/50 mass fraction), R22/R152a(10/90), R22/R152a/R124(30/25/45) are good for the substitutes of R12 and R32/R134a(30/70) is appropriate for that of R22 in view of COP and VCR.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.8 no.3
• /
• pp.43-56
• /
• 2020

Purpose - This study was carried out to analyze the influential factors of how consumers methodize purchasing agricultural products via direct market. It further utilizes the Discrete Choice Model to analyze consumer decision specifically with regards to individual markets and store attributes. Research design and methodology - This study will use the multinomial logit model to interpret the influential factors behind selecting a specific market to purchase from. This study establishes 'online direct-purchase' as the base category with 'direct farm markets', 'local foods direct markets', 'produce boxes (CSA)' as substitutes. Results - Firstly, the variety of products, price and freshness had a positive influence on choosing 'direct farm markets' while convenience of payment and transportation had a negative influence. Second, freshness and store attributes had a positive influence on choosing 'local foods direct markets' but product price and packaging, location accessibility had a negative influence. And although product creditability had a positive influence on purchasing 'produce boxes (CSA)', product price had a negative influence. Conclusions - Accordingly, there is a need for the South Korean government to encourage the adoption of mobile payment through smartphone applications in direct farm markets to vitalize direct agricultural purchasing. However, this does need to be approached cautiously as price has a conflicting affect for each method of purchase.

• Korea journal of population studies
• /
• v.21 no.1
• /
• pp.5-41
• /
• 1998

Over the past 30 years, Korea experienced demographic transition which typically substitutes quality(education) for quantity(number) of population. This paper decomposed labor supply into quantity and quality aspects and estimated the respective employment elasticities of economic growth in the past. Then, based on the assumptions about the future population (by age, sex and education) and labor force participation rates, the future labor supply(both quantity and quality) is projected and growth potential of the Korean economy is evaluated. The result shows that labor supply in Korea is relying gradually more on the qualitative rather than the quantitative aspect but since the increase in the former will not fully compensate the decrease in the latter, the potential growth rate of the Korean economy will be substantially reduced in the futrue.

• Journal of Welding and Joining
• /
• v.31 no.4
• /
• pp.1-6
• /
• 2013

Nowadays, the weight lightening of automotive is required as conserving the environment has become a major worldwide issue. To solve this issue, various researches for the use of light materials(Alalloy, Mgalloy)and ultra high strength steel as substitutes of the current structural material have been carried out. Application of laser stitch welding to the assembly of automotive produces improvement in strength, lightening of body, higher fuel efficiency, lower production cost as well as reduction in assemble line due to its fast welding speed, superior accessible and weld quality. This process overcomes the shortcomings of the current resistance spot welding such as high electricity consumption, electrode replacement, and economical, technical limitation in design and production method of automotives.

• The Korean Journal of Food And Nutrition
• /
• v.21 no.2
• /
• pp.190-196
• /
• 2008

This study was performed to aid the development of a reduced-calorie ssanghwa beverage, by using substitutes for high fructose com syrup(HFCS). The relative sweetness levels of HFCS, aspartame, acesulfame-K, and glucosyl stevia solutions were examined in comparison to a 10% sucrose solution in a binary solution model. And the sensory properties of ssanghwa beverages containing aspartame, acesulfame-K, and glucosyl stevia were evaluated at the equi-sweetness to HFCS. In the binary solution model, the relative sweetness of HFCS to sucrose was 0.8, while the values for aspartame, acesulfame-K, and glucosyl stevia were 140, 170, and 100, respectively. Sweet taste and sweet after taste were not significantly different between the HFCS, aspartame, acesulfame-K, and glucosyl stevia solutions. On the other hand, bitter taste, first taste, and overall eating quality were significantly different between the HFCS and aspartame solutions and between the acesulfame-K and glucosyl stevia solutions. Finally, the ssanghwa beverages sweetened with HFCS, acesulfame-K, and aspartame only had slight differences in sensory properties. However, the sensory properties of the beverages sweetened with HFCS and glucosyl stevia, respectively, were significantly different.

• The Korean Journal of Food And Nutrition
• /
• v.21 no.2
• /
• pp.197-203
• /
• 2008

This study was performed to aid the development of a reduced-calorie ssanghwa beverage, by using substitutes for high fructose com syrup(HFCS). Sensory scores were examined for ssanghwa beverages containing different levels of glucosyl stevia, aspartame, and acesulfame-K(0, 50, and 100%, respectively) in place of HFCS. The results showed that sensory scores were not significantly different for the beverages containing different levels of acesulfame-K, including aftertaste, ssanghwa taste, and overall eating quality. In contrast, the sensory scores of beverages containing 0 and 100% glucosyl stevia were significantly different. Data were also gathered comparing the sensory scores of beverages according to the different types of sweeteners. Bitter taste and astringency were not significantly different between the beverages sweetened with HFCS, KP(containing 50% acesulfame-K and 50% aspartame), SP(containing 50% glucosyl stevia and 50% aspartame), and SK(containing 50% glucosyl stevia and 50% acesulfame-K), respectively. Finally, aftertaste and overall eating quality were not significantly different between the HFCS and SP sweetened beverages.

• Food Science of Animal Resources
• /
• v.25 no.1
• /
• pp.60-65
• /
• 2005

Antioxidant films are one active packaging technology that can extend food shelf-life through preventing lipid oxidation, stabilizing color, maintaining sensory properties and delaying microbial growth in foods. Because raw, fresh and minimal processed foods are more perishable during storage or under display conditions than further processed foods, they rapidly lose their original quality. Foods are susceptible to physical, chemical, and biochemical hazards to which packaging films can be effective barriers. Although films incorporated natural (tocopherols, flavonoids and phenolic acids) or synthetic antioxidants (BHT, BHA, TBHQ, propyl gallate) have been extensively tested to improve quality and safety of various foods, food applications require addressing issues such as physical properties, chemical action, cost, and legal approval. Increased interest in natural antioxidants as substitutes for synthetic antioxidants has triggered research on use of the new natural antioxidants in films and coatings. Use of new components (phytochemicals) as film additives can improve food quality and human health. The biosynthesis of plant phenolics can potentially be optimized by active coatings on harvested fruits and vegetables. These coatings can trigger the plants natural proline-linked pentose phosphate pathway to increase the phenolic contents and maintain overall plant tissue quality. This alternate metabolic pathway has been proposed by Dr. K. Shetty and is supported by numerous studies. A new generation of active food films will not only preserve the food, but increase food's nutritional quality by optimizing raw food biochemical production of phytochemicals.

• Journal of Family Resource Management and Policy Review
• /
• v.13 no.1
• /
• pp.1-21
• /
• 2009

The purposes of this study are to provide background information to develop a family-friendly work policy and to increase the effectiveness and feasibility of this policy. We surveyed the performance of family-friendly work policies, and workers‘ needs and utilizations of 17 family-friendly work policies. We also examined the factors that influence the utilization of family-friendly work policies. The study sample consists of 197 working mothers who have at least one child under age 10. The major findings are as follows: 1) The most-needed family-friendly work policy among working mothers is child care leave 2) Of those family-friendly work policies that are not currently provided, the most-needed policy is family care leave 3) The size of firms, the provision of substitutes, and 40-hour work schedules are statistically significant variables that influence the provision of necessary family-friendly work policies and 4) In addition, the work place culture is a very important factor related to the utilization of work- and family-friendly policies.

• Environmental and Resource Economics Review
• /
• v.19 no.3
• /
• pp.633-658
• /
• 2010

In this paper, we estimate the Translog cost function in Korean manufacturing, using capital (K), labor (L), material (M), electricity (E), fuel (F) data over the period from 1970 to 2005. Especially, this paper investigates the impact of imposing concavity in the estimation of a Translog cost function. Although the value of log-likelihood is somewhat reduced in a concavity imposed function rather than a function which is not, a concavity imposed function satisfies regularity conditions (monotonicity, positivity, concavity) at all data points. We also calculate price elasticities using a concavity imposed Translog cost function. Electricity complements capital so electricity demand increases as capital demand increases. Meanwhile, electricity substitutes labor, fuel, and material. These results show that Korean manufacturing experienced a structural change of increase in electricity demand.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.2
• /
• pp.9-20
• /
• 2020

The study investigates a recent surge of cash literature by using a sample of hospitality firms to gain a new understanding of corporate cash holdings. Past literature states that there is a substantial variation of liquidity across industry groups. Existing literature predominantly refers to US-listed firms and focus on either hotels or restaurants and not the hospitality industry as a whole. Therefore, we provide a comparative study of cash holdings behaviour between hospitality and non-hospitality firms from an emerging market context. Using a sample of public listed hospitality firms from 2002 to 2013, dynamic panel regression techniques are used to study the relationships between firm characteristics and cash levels. Also, the non-parametric Wilcoxon-Mann-Whitney test was carried out to examine the time and sectoral differences in cash holdings. In addition, the panel regression techniques are used to investigate the relationships between firm characteristics and level of corporate cash holdings. The results reveal that firm characteristics do matter in hospitality firms. We find that firm size, capital expenditures, and liquid assets substitutes are negatively related to cash level. The results support trade-off theory and the pecking order theory. This study incrementally explains the cash holdings behaviour of hospitality firms in emerging market.