• Journal of the Korea Convergence Society
• /
• v.11 no.1
• /
• pp.161-168
• /
• 2020

This study is designed to develop a walker to assist the elderly in safe, independent walking. To this end, problems were identified through analysis of the walker for the elderly and user observations were used to identify problems and needs. The product analysis showed that most elderly walkers tend to prioritize their functions. In addition, user observations showed that most users had positive perceptions about the function, but that structural aspects, such as operation methods and stability, had negative consequences. A total of five design guidelines were derived based on the problems and needs derived. The design guidelines were designed to focus on improving structural problems rather than functional parts, and to orientate safety over functional priorities. Five design guidelines derived from this study could be used as basic data for the manufacture of walkers that reflect the views and needs of the elderly in the future in the manufacture and design of walkers for the elderly.

• Natural Product Sciences
• /
• v.20 no.4
• /
• pp.274-280
• /
• 2014

Six compounds were isolated from the n-BuOH fraction of the aerial parts of Aruncus dioicus var. kamtschaticus including: sambunigrin (1), prunasin (2), aruncide A (3), aruncide C (4), 1-O-caffeoyl-${\beta}$-D-glucopyranose (5), and caffeic acid (6). Their structures were confirmed by comparing the spectral data with those reported in the literature. The isolated compounds (1 - 6) were then examined for their cytotoxic effects towards MCF-7, HL-60, and HeLa cancer cell lines, as well as their DPPH radical scavenging activity. The results indicated that compound 4 possessed the strongest inhibitory effect toward HeLa cell line with $IC_{50}$ value of $5.38{\pm}0.92{\mu}M$. Compound 3 possessed selective cytotoxic activity on HL-60 cells with $IC_{50}$ value of $6.27{\pm}0.17{\mu}M$, compound 5 was found as the best in inhibiting proliferation with $IC_{50}$ value of $2.25{\pm}0.09{\mu}M$, and the other compounds showed significant inhibition with $IC_{50}$ values ranging from 6.10 to $11.27{\mu}M$. Compound 5 also displayed the strongest cytotoxic effect toward MCF-7 cell line ($IC_{50}$ $4.32{\pm}0.15{\mu}M$). Both 5 and 6 demonstrated strong radical scavenging activity ($IC_{50}$ $6.87{\pm}0.03$ and $4.33{\pm}0.22{\mu}M$, respectively). Compounds 1 and 5 were isolated for the first time from this plant.

• Journal of the Korean Chemical Society
• /
• v.38 no.5
• /
• pp.366-371
• /
• 1994

The kinetics of the hydrolysis of 5,6-dihydro-1,4-thiazine derivatives was investigated by ultraviolet spectrophotometry in $H_2O$ at 25$^{\circ}C$. A rate equation which can be applied over a wide pH range was obtained. The substituent effects on the hydrolysis of 5,6-dihydro-1,4-thiazine derivatives were studied and the rate of hydrolysis was shown to be accelerated by electron donating groups. Final product of the hydrolysis was 2-(N-acetylaminoethylthio)-acetoacetanilide enol from Judging from the results of the rate equation, general base effect, activation parameters and final products, the hydrolysis of 5,6-dihydro-1,4-thiazine derivatives seemed to be initiated by the neutral $H_2O$ molecule which does not dissociate at pH below 10.0, but proceeded by the hydroxide ion at pH above 11.0, and those two reactions occurred competively at pH 10.0∼11.0 range. On the basis of these findings a plausible mechanism for the hydrolysis of 5,6-dihydro-1,4-thiazine derivative was proposed.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.32 no.3
• /
• pp.462-473
• /
• 2008

In recent years, Korea's apparel exports to the USA have faced a great threat, as the trade environment around the world has changed continually. The purpose of this study is to analyze the competitive position of Korean apparel exports to the USA, and to enhance export competitiveness by applying to offshore sourcing. The trade data of the Office of Textiles and Apparel(OTEXA) in the U.S. Department of Commerce were selected for inquiry about export competitiveness of apparel products made in Korea. In addition, we targeted members of the Korea Apparel Industry Association among the 500 exporters of clothing items in "The Import and Export Textile Product 2003." A total 70 sheets were analyzed. The results of this study were as follows: 1) Korean apparel exports to USA have decreased by 20-35 percent per year since 2005 under the Free Trade Area, showing that Korean apparel industries have not adapted to the new trade environment. Although Korean apparel exports to USA have indicated a trade surplus from now on, Korean apparel industries should find new ways to overcome this situation, diminishing exports and increasing imports. 2) Korean apparel companies selected more offshore sourcing than domestic sourcing. Also, as Korean apparel companies manufactured apparel products offshore, foreign subcontracting outranked manufacturing in their own foreign plants. When they chose foreign countries to source, they turned mainly to China and Vietnam. Also, they considered the target country's manufacturing price, labor stability, apparel products, quality, lead time, and so on. In order to increase apparel exports, Korean apparel industries should focus more on developing competitively new apparel products, improving the ability of sourcing management, and establishing on-the-spot agencies.

• Journal of IKEEE
• /
• v.7 no.1 s.12
• /
• pp.88-96
• /
• 2003

In this paper, We designed and implemented a linear high-power amplifier which can be used for the commercial service in band of $1.9GHz(1.93{\sim}1.99GHz)$ at U.S.A. The output power of the implemented linear high power amplifier is 25W. In order to satisfy IMD characters decided by FCC, the Feedforward linearization techniques has been used. The used feedforward method has improved the IMD characteristics from 10.51dBc to 19.01dBc in each power level from 1W(30dBm) to 25W(44dBm). The IMD level of the final output shows from minimum 64.84dBc to maximum 68.17dBc. Because this good characteristics of IMD, the LPA is expected to use as a commercial product of PCS base station.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.1
• /
• pp.160-166
• /
• 2008

A DNA fragment containing 2,079 base pairs from Bacillus circulans CGMCC 1416 was cloned using degenerate PCR and inverse PCR. An open reading frame containing 981 bp was identified that encoding 326 amino acids residues, including a putative signal peptide of 31 residues. The deduced amino acid sequence showed the highest identity (68.1%) with $endo-{\beta}-1,4-D-mannanase$ from Bacillus circulans strain K-1 of the glycoside hydrolase family 5 (GH5). The sequence encoding the mature protein was cloned into the pET-22b(+) vector and expressed in Escherichia coli as a recombinant fusion protein containing an N-terminal hexahistidine sequence. The fusion protein was purified by $Ni^{2+}$ affinity chromatography and its hexahistidine tag cleaved to yield a 31-kDa ${\beta}$-mannanase having a specific activity of 481.55U/mg. The optimal activity of the purified protein, MANB48, was at $58^{\circ}C$ and pH 7.6. The hydrolysis product on substrate locust bean gum included a monosaccharide and mainly oligosaccharides. The recombinant MANB48 may be of potential use in the feed industry.

• Journal of Soil and Groundwater Environment
• /
• v.7 no.4
• /
• pp.40-47
• /
• 2002

The practices of the construction and management of the petroleum and hazardous chemical compound storage facilities in Korea were investigated extensively, and the problems were identified. The advanced technologies in the U.S.A were comparatively studied. Considering the effectiveness of leak prevention and applicability, the following measures were suggested. To prevent corrosion of a tank, a clad tank, an interior lining tank, or a double-wall tank were thought to be the most cost effective. For piping. use of non-metalic materials was suggested. A catchment basin seemed to be effective for preventing spills. For monitoring of leaks, constructions of more than one of detection systems, such as an automatic leak detection device. a vapor detection system, a groundwater monitoring system, or a double-wall monitoring system, were recommended.

• Archives of design research
• /
• v.4 no.1
• /
• pp.61-73
• /
• 1991

The exhibition activity that a company is rendering to their consumers for the purpose of advertisement, sales promotion and enhancement of company inage get more and more internationalized and specialized. A company is changing from mass production system to small quantity production of various kinds to meet consumer's individualization and differentiation. Also, a company is experiencing a major change in their marketing strategy. As the society is entering on Information Age, the contents that a company intends to give consumer may be different individually. If a consumer is informed wrong information of the goods, a company needs a place to meet consumer face to face where the consumer feels and understands the substance of the goods. This is the current characteristics of Exhibition Media. Based on the result of the current Special Exhibition home and abroad along with background and characteristics of special Exhibition, this study sets a following task reflecting the general trend of social, cultural and economic atmosphere. First, Current Exhibition Industry will be diversified into more Specialized Exhibition, while our Exhibition Industry is very shaky under severe international competition. Also, Exhibition Plan that involves with architecture, interior, graphic, industrial design and advertisement, etc., needs international competitiveness while enhancing identity of Exhibition Plan along with comprehensive marketing strategy in the future. Second, Among most of the local special Exhibitions which invite the general public are normally invited for company public relation contrary to those of U.S.A. and Europe. This signifies of our industrial and social structure's by-product. As the future exhibition become Information Com$$\mu$ication Exhibition which requires specialized technical explanation, the correct description of the goods should be set as a Judgement basis of Exhibition Plan. Third, In parallel with increase of the Exhibition, the equipment expenses of a company goes up continuously. In view of this, a study $$\mu$t be oriented for re-use and curtailment of expenditure of those equipment. Also, as the use of Assembly System B on the rise as a result of diversification of special Exhibition, a study on the development of new material & design for Exhibition Equipment only B required.

• Archives of Reconstructive Microsurgery
• /
• v.24 no.1
• /
• pp.13-15
• /
• 2015

Purpose: Since the hand elevation test was first introduced by Ahn in 2001, it has been one of most performing provocative test for diagnosing carpal tunnel syndrome. Although many studies have been published on the hand elevation test, there are no study that can explain why false-negative results of hand elevation test appears in carpal tunnel syndrome patients diagnosed by electromyography (EMG) findings. Therefore we searched out whether hand elevation test is related with EMG severity. Materials and Methods: We made a retrospective study of 654 bilateral carpal tunnel syndrome patients. Among them 134 were studied which had different hand elevation test results on each hands. The paired samples t-test was used to compare the EMG severity of each group. The relationships between hand elevation test and EMG severity were examined using Pearson-product correlations. Comparing whether the frequency of false negative hand elevation were different between both hands, and whether the severity of EMG depends on which side of hand is, was evaluated with Mann-Whitney U-test. Results: Severity of EMG in positive group was moderate to severe on average, whereas mild to moderate on negative group, with significant difference statistically (p<0.001). Correlation between the hand elevation test results and EMG severity also showed significance statistically (p<0.001). Conclusion: Mild severity of EMG was found out to be the factor affecting the false results. However, EMG severity and hand elevation test shows a meaningful correlation, supporting the value of hand elevation test.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.5
• /
• pp.373-377
• /
• 1990

Volatile components of whole sardine sauce which was prepared with $7\%$ of complex enzyme-2000($2.18{\cdot}10^4\;U/g solid$), mixed with $6\%$ of invert sugar and heated at $90^{\circ}C$ for 2 hours were compared with those of without invert sugar. Thirty seven kinds were identified from the whole volatile components of hydrolysate heated without invert sugar and fourty three kinds were identified from the hydrolysate heated with $6\%$ of invert sugar. Amines were not detected from the whole volatile components of the chopped whole sardine hydrolysate. Considerable amount of 2,3-dihydrobenzofuran and 2-acetylpyrrole, a little amount of 2,5-hydrofuran, 2-ethylbutanol, 2-pyrone, 2-acetylfuran, 2,6-dimethylpyrazine, 2-acetylpyrazine, 5-methyl-2-furfural, furfuryl acetate, butylpyrrole and 2-methyl-3-hydroxypyrone were detected in the hydrolysate thermally treated with $6\%$ of invert sugar while these were not found in the hydrolysate heated without invert sugar. But the amount of 2-methyt-1-propa-not, hexane, butyl acetate and butyl alcohol were decreased, and acetic acid and butanoic acid were detected as volatile fatty acids.