• Proceedings of the PSK Conference
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• 2002.10a
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• pp.288.1-288.1
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• 2002

Herbal medicines are increasingly being utilized to treat a wide variety of disease processes. The aim of this study was to evaluate the ability of aqueous extract from the roots of Platycodon grandiflorum A. DC (Campanulaceae). Changkil (CK). to affect cellular response in primary cultures of rat hepatocytes to t-butyl hydroperoxide (t-BHP) induced oxidative stress and hepatotoxicity. CK-treated cells showed an increased resistance to oxidative challenge. as revealed by a higher percent of survival capacity in respect to control cells. CK added prior or simultaneously with I-BHP reduced enganced lipid peroxidation measured as production of malondialdehyde and enhnaced intracellular reduced glutathinoe depletion by t-BHP. Furhtermore. CK protected from the t-BHP-induced intracellular generation of reactive oxygen species assessde by montioting dichlorodihydrofluorescein fluorescence. it can be concluded that CK exerts an antioxidant action insice the cell. responsible for the abserved modulation of the cellular response to oxidative challenge. and CK have a marked anitioxdative and hepatoprotective potency.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.2
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• pp.127-131
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• 1993

A newly developed waste-water treatment system for small scale piggery wastes through a demonstration trial at a farm. The results are summarized as follows. 1. The amount of piggery wastes produced was 10.2kg/head/day, which consisted of 2.8kg solid wastes and $7.41{\ell}$ fluid wastes. 2. The unit BOD discharge from piggery wastes was 207g/head/day, among which 81 percent was originated from solid waste and 19 percent from fluid waste. 3. After the treatment of the waste-water through the system, BOD, total N and total P were lowered by 99, 78, 74 percent, respectively : the BOD, total N and total P in the final effluent were $52mg/{\ell}$, $213mg/{\ell}$ and $28mg/{\ell}$, respectively. 4. The results of the trials suggested that the system could be recommended for the practical use at the farms.

• Phonetics and Speech Sciences
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• v.11 no.4
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• pp.45-53
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• 2019

The purpose of this work was to examine the factors affecting the identities of the voiceless plosives, i.e. English [p, t, k] and Korean [p^h, t^h, k^h], from the spontaneous speech corpora. The factors were automatically extracted by a Praat script and the percent correctness of the discriminant analyses was incrementally assessed by increasing the number of factors used in predicting the identities of the plosives. The factors included the spectral moments and tilts of the plosive release bursts, the post-burst aspirations and the vowel onsets, the durations such as the closure durations and the voice onset times (VOTs), the locations within words and utterances and the identities of the following vowels. The results showed that as the number of factors increased up to five, so did the percent correctness of the analyses, resulting in 74.6% for English and 66.4% for Korean. However, the optimal number of factors for the maximum percent correctness was four, i.e. the spectral moments and tilts of the release bursts and the following vowels, the closure durations and the VOTs. This suggests that the identities of the voiceless plosives are mostly determined by their internal and vowel onset cues.

• Journal of Korean Vacuum Science & Technology
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• v.4 no.4
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• pp.112-121
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• 2000

The paper investigates electrical discharge properties in neon gas mixed with xenon. The breakdown temperature T$\sub$b/ and voltage V$\sub$b/ are obtained in terms of the gas mixture ratio X. It is shown that the breakdown voltage decreases, reaches the minimum value at X=0.02 and then increases again, as the mixture ratio X increases from zero to unity. Therefore, mixing the neon gas with a few percent of xenon is the most beneficial to reduce the breakdown voltage. Plasma density at breakdown in neon gas mixed with xenon is described in terms of the gas mixture ratio. The optimum value of mixture ratio for highest plasma density is found to be Xm=0.03. A preliminary experiment of AC-PDP is carried out for neon gas mixed with a few percent of xenon to verify some of the theoretical models. The experimental data agree qualitatively well with theoretical predictions.

• Journal of the Korean Home Economics Association
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• v.36 no.1
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• pp.1-11
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• 1998

The purpose of this study is to find troubles in producing and using the reclaimed soaps to get the solutions of their troubles. Five kinds of reclaimed soaps were taken from religious or civic organizations and nine kinds of soaps were made by adding sodium hydroxide of different concentrations to the used vegetable oil in our laboratory. Washing efficiency, pH test, BOD, and skin irritability of the reclaimed of manufactured soaps were examined. The washing efficiency of the manufactured soaps were ±80%. The percent of free-alkali tended to increase as the amount of NaOH increased. The skinirritability was proportional to the amount of NaOH added. To make the reclaimed soap, the best percent of NaHO to used oil is 17% or 18% and this ratio(17%∼18%) should be kept. Manufactured soaps by this ratio have good apperance condition and washing efficiency. And also they have low skin irritability and free-alkali. This study has the limitations that the skin irritability test can have individual and the collected soaps couldn't represent all kinds of recaimed soap.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1559-1562
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• 2002

This paper describes a 0.13um ultra-high speed 1Mb CMOS SRAM macro with 1.7ns access time. It achieves ultra-high speed operation using two novel approaches. First, it uses process insensitive sense amplifier (Double-Equalized Sense Amplifier) which improves voltage offset by about 10 percent. Secondly, it uses new replica-based sense amplifier driver which improves bit- line evaluation time by about 10 percent compared to the conventional technique. The various memory macros can be generated automatically by using a compiler, word-bit size from 64kb to 1 Mb including repairable redundancy circuits.

• Geomechanics and Engineering
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• v.7 no.4
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• pp.431-458
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• 2014

Construction of a new cavern close to an existing cavern will result in a modification of the state of stresses in a zone around the existing cavern as interaction between the twin caverns takes place. Extensive plane strain finite difference analyses were carried out to examine the deformations induced by excavation of underground twin caverns. From the numerical results, a fairly simple nonparametric regression algorithm known as multivariate adaptive regression splines (MARS) has been used to relate the maximum key point displacement and the percent strain to various parameters including the rock quality, the cavern geometry and the in situ stress. Probabilistic assessments on the serviceability limit state of twin caverns can be performed using the First-order reliability spreadsheet method (FORM) based on the built MARS model. Parametric studies indicate that the probability of failure $P_f$ increases as the coefficient of variation of Q increases, and $P_f$ decreases with the widening of the pillar.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.33-41
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• 1999

More than 90 percent of traffic accidents were caused by human errors in driving situation. However, the ergonomic studies were not enough to prevent these human errors. Especially, drivers acquire more than 70 percent of information using the vision, and this shows the importance of consideration about the driver's visual cognition characteristics. Consequently, the driver's cognition time and the cognition accuracy were measured for the Instrument Panel(IP) of vehicle cockpit in this study. For the experiment, subjects were divided in two groups. The first group of subjects had their own vehicles and the driver license, and the second group of the subjects didn't have own vehicle but had the driver license. IP Images were used in the experiment and the each image was made by changing layout of objects within devices. The results showed that there were no differences for the cognition time and the accuracy between images within the group, and the results between the groups showed the same trend.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.117-120
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• 2002

Scelionid eggParasitoids Play an important role in biological control of some economically important pentatomids. Stink bug (Canthecona furcellatta Wolff,) is an important predator of Tasar silkworm larvae (Antheraea mylitta D.) and causes 30-40 percent loss in tasar silk industry. Psix striaticeps (Scelionid: Hymenoptera) has been found to be an important egg parasitoid. The parasitization potential of f striaticeps is mere than 60 percent and the sex ratio is female oriented. Studies indicate that the maintenance of existing scelionid population by avoiding harmful practices and the augmentation of scelionids either directly releasing them in the field or by indirectly making the field environment more favorable for them is an important aspect to control the pentatomid population in sericulture. Female bias sex ratio is advantageous to increase the parasitoid population in the field. 24-hour-old egg of stink bug and one-day old parasitoid is suitable for producing maximum progeny. 1 : 30 of parasitoid: host ratio is needed to regulate the estimated population in silkworm rearing field.

• Journal of the Korean Home Economics Association
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• v.36 no.7
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• pp.57-67
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• 1998

This study was to compare the financial status between elderly households - retired vs employed. The sample obtained from 1994 KHPS, and consisted of 628 Korean aged households who are currently married. Statistics employed to analyze the data are mean, frequency, percentile, t-test, and relative-ratio. The results of this study were as follows ; In income sources, earned income was majority of employed households, but the percent of unearned income was greater than retired households. While the percent of cloth, education, recreation expenditures were high in employed, and medical, housing expenditures wee high percentage in retired. The percentage of real asset(housing) was majority of total asset in two groups. And the percentage of safe liquid asset of retired households was relatively higher than employed households.