• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.416-421
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• 2007

ZigBee is becoming a promising communication protocol for wireless sensor networks based on low-power consumption. In case of a ZigBee network requesting continuous transmission of sensed data, the required bandwidth can be overwhelm the maximum transmission rate of 150Kbps. However, the ZigBee router which delivers data from source node to destination node can transmit data at most in a half of maximum rate because the router can not send and receive the data simultaneously. In this paper, we propose and implement a dual-channel router which can send and receive data simultaneously. Also, we propose a centralized channel allocation algorithm to allocate different channels to each module. The experiment result by the proposed dual-channel router shows a maximum throughput of 150Kbps as large as twice of normal single-channel router.

• Structural Monitoring and Maintenance
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• v.11 no.1
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• pp.41-55
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• 2024

This study aims to determine the characteristics of concrete as identified by Rebound Hammer and Ultrasonic Pulse Velocity (UPV) tests, focusing particularly on their efficacy in estimating compressive strength of concrete material. The study involved three concrete samples designed to achieve a target strength of 29 MPa, comprising normal concrete, instant concrete, and concrete with additives. These were cast into cube specimens measuring 150×150×150 mm. Compressive strength values were determined through both destructive and non-destructive testing on the cubic specimens. As a result, the non-destructive methods yielded varying outcomes for each correlation approach, influenced by the differing constituent materials in the tested concretes. However, normal concrete consistently showed the most reliable correlation, followed by concrete with additives, and lastly, instant concrete. The study found that combining Rebound Hammer and UPV tests enhances the prediction accuracy of compressive strength of concrete. This synergy was quantified through multivariate regression, considering UPV, rebound number, and actual compressive strength. The findings also suggest a more significant influence of the Rebound Hammer measurements on predicting compressive strength for BN and BA, whereas UPV and RN had a similar impact on predicting BI compressive strength.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.7
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• pp.1205-1219
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• 2010

This study analyzes the conditions and products of internet shopping malls that sell natural dyeing products. In this study, 98 natural dyeing internet shopping malls were selected. The results of this study are as follows. The locations of the internet shopping malls were Gyeonggi-do, Seoul, Jeollanam-do, Gyeongsangbuk-do, Gwang-ju (city), Daegu (city), Busan (city), Gyeongsangnam-do, and Jeju-do. The most frequent dyes of the natural dyeing products were loess, followed by charcoal, indigo, and persimmon. Indigo was most frequently used in Seoul, with loess and charcoal most frequent in Gyeonggi-do. Persimmon, indigo, loess, and charcoal were mainly used in Jeollanam-do, with persimmon and loess in the Gyeongsangbuk-do, and persimmon in Jeju-do. The highest ordered product categories were accessories, followed by adult clothing, interior decoration products, and bedding. The most frequent products were bedclothes, followed by scarves, female shirts, blouses, pillows, female jackets, and vests. Regarding the price of products, 150,000-200,000 won was the highest for the Saenghwal Hanbok, with 10,000-30,000 won for underwear, 30,000-60,000 won for accessories, and 100,000-150,000 won for bedding. Concerning product information, 58.2% of internet shopping malls offer the product size and almost half of them did not show the properties or directions for handling the product. Based on the research results, the problems of the conditions and products of natural dyeing internet shopping mall were derived. The results show that the natural dyes of internet shopping malls lacked regional symbolism, the products were not specialized, and product information was not fully offered to consumers. To solve these problems, the strategies for marketing the promotion of the natural dyeing internet shopping mall were, ‘Using natural dyes from local resources’, ‘Market oriented and specialized item design’, and ‘Offer right product information’.

• The Research Journal of the Costume Culture
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• v.18 no.2
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• pp.382-395
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• 2010

The purpose of this study was to compare clothing values and clothing purchasing behaviors between Korean and American college students, especially men. Also this study was to analyze the clothing values effect on the clothing purchasing behavior. For the practical study, 200 questionaries were surveyed, 110 from Korea and 105 from American. The average and frequency, t-test, $\chi^2$, multi-variate analysis of variance and factor analysis were used for this study. The result showed, first, there were little differences in the clothing value aspect. Both Korean college men and American college men considered the theoretical value to be most important, however, the American college men were higher than the Korean college men for theoretical, economic and political values. Compared to the Americans, the Koreans considered social clothing value to be more important but theoretical, economic and political values were less important. Second, there were some differences in most of all the clothing purchasing behaviors. There were slight differences in the reasons for the purchases between Korean and American college men. Both of them said that they purchase clothes to satisfy their needs. Regarding the information sources for the purchase, The Korean college men were slightly higher than the American college men for the media information sources and lower than them for the human information sources. Regarding the place where the clothes were purchased, the Korean college men preferred to make purchases at department stores, and the American college men preferred shopping malls. Regarding the monthly expenses for clothing, less than 50,000 won($50) was the average for most of the Korean women, but most of the American college women spent 100,000~150,000 won($150) per month. Third, the clothing value was different in the reason for purchasing, the purchasing information source, the purchasing place, and the monthly expenses for the clothing.

• Korean Journal of Agricultural Science
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• v.44 no.2
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• pp.211-220
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• 2017

We conducted this study to determine the recommended application rate of fertilizer for Houttuynia cordata Thunb cultivation. The effects of various application levels of N, $P_2O_5$, and $K_2O$ fertilizers on the growth of this plant were investigated and the associated changes in soil properties were evaluated in the field. Soil pH at harvest time of Houttuynia cordata Thunb did not differ from that before fertilization, whereas EC tended to decrease during cultivation. The soil organic matter (SOM) and available phosphorus increased after treatment, and the amount of applied fertilizer ($P_2O_5$) and available phosphorus were proportional. The nitrogen absorption amount increased in N 100% treatment, but decreased in N 150% treatment. The phosphorus absorption amount rose with the fertilizer treatment concentration until $P_2O_5$ 150% treatment. The amount of absorbed potassium decreased in treatments with $K_2O$ 150% and $K_2O$ 200%. The plant length was the longest in N 100%, $P_2O_5$ 150%, and $K_2O$ 200%. The stem diameter was estimated to be 3.46 - 3.67 mm in N 100 - 200% treatment, 3.55 - 3.67 mm in $P_2O_5$ 100 - 150%, and 3.79 mm in $K_2O$ 200%. The number of tillers did not differ amongst fertilization treatments. The fresh weight was summed to be 3.67 ton/10 a in N 100% treatment, 3.79 Mg/10 a in $P_2O_5$ 150%, and 3.83 Mg/10 a in $K_2O$ 150%. Thus, the relationship between the fertilizer amount and yields of the plant showed that the most economical quantity of fertilizers should be 10.2 N kg/10 a, 5.5 $P_2O_5$ kg/10 a, and 8.2 $K_2O$ kg/10 a for Houttuynia Cordata Thunb.

• Korean Journal of Materials Research
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• v.13 no.3
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• pp.150-154
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• 2003

Amorphous carbon nitride films were deposited on Si(001) substrates by a plasma enhanced chemical vapor deposition technique (PECVD) using $CH_4$and $N_2$as reaction gases. The growth and film properties were investigated while the gas ratio and the working pressure were changed systematically. At 1 Torr working pressure, an increase in the $N_2$partial pressure results in a significant increase of the deposition rate as well as an apparent presence of C ≡N bonding, while little affecting the microstructure and amorphus nature of the films. In the case of changing the working pressure at a fixed $N_2$partial pressure of 98%, a film grown at a medium pressure of $1${\times}$10^{-2}$ Torr shows the most prominent C=N bonding nature and photoluminescent property.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.1
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• pp.150-153
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• 2015

An energy-efficient 64-bit prefix adder is proposed for micro-server processors based on both semidynamic and bypassing structures. Prefix adders consist of three main stages i.e. propagate-generate (PG) stage, carry merge (CM) tree, and sum generators. In this architecture, the PG and CM stages consume most of the power because these are based on domino circuits. This letter proposes a semidynamic PG stage for its energy-efficiency. In addition, we adopt the bypassing structure on the CM tree to reduce its switching activity. Experimental results show 19.1% improvement of energy efficiency from prior art.

• Environmental Analysis Health and Toxicology
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• v.10 no.3_4
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• pp.7-13
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• 1995

The most periodlengths($\tau$) of conidiation of Neurospora were shortened in the medium with Li$^+$, Rb$^+$, and Cs$^+$ under the blue or green light. The higher the concentration of the heavy metal elements are, the shorter the circadian lengths are. The largest differences between the maxima- and minima circadian lengths showed in the medium with LiCI, RbCl, and CsCI under the blue lights at 150 Lux, while the little differences of circadian lengths presented in 1 mM heavy metal elements at the 270Lux blue light. Li$^+$ under the blue light effected extremely much and in the order of Rb$^+$ and Cs$^+$ on the conidiation of Neurospora. Under the green lights at 270Lux, the smallest changes of the circadian lengths are resulted in the medium with heavy metal elements. The other way at the green light 150Lux, the conidiation is stimulated by lmM LiCI or RbCl for the average 0.71h and 0.29h longer than the periodlength of control 28.34h. The medium with Li$^+$ under the green light has less effect on the conidiation rhythm of Neurospora than with Rb$^+$ or Cs$^+$.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.150-154
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• 1998

Epidural steroid injection have become one of the most frequently applied conservative option for the management of acute and chronic back pain. As the indications for epidural steroid injections increase so do the adverse responses associated with this procedure. This study reports the succession of 3 patients who developed galactorrhea and hyperprolactinemia after recieving an epidural steroid injection for lumbar radiculopathy and low back pain. Serum prolactin level was elevated in accordance with epidural injection of corticosteroid. We measured the serum prolactin level by immunoradiometric assay method and peak serum prolactin level at above 500, 144.2, 150.3 ng/ml respectively. Also we found the serum prolactin level decreased to normal values 3 wks after corticosteroid injection. Galactorrhra ceased in advance of decrease of serum prolactin level. That "Hyperprolactinemia and galactorrhea can occur following epidural steroid injection", requires a much larger prospective investigation.

• Solar Energy
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• v.16 no.2
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• pp.87-96
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• 1996

Electochromic tungsten oxide thin films were prepared on the ITO coated glass by rf magnetron sputtering from a compressed powder tungsten oxide target in an argonoxygen atmosphere. The influence of the preparation conditions, especially the substrate temperature, on the chemical stability of film was investigated. These films were cycled in 0.6M $LiClO_4$ and 0.6M $H_2SO_4$ electrolyte respecitively, and exhibited electrochromic behavior upon the electrochemical insertion and extraction of ion. Among these tungsten oxide thin films, films prepared at a substrate temperature of $150^{\circ}C$ were found to be most stable in terms of cyclic durability.