• Journal of Korean Society for Quality Management
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• v.29 no.2
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• pp.37-45
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• 2001

A survival variable is a non-negative random variable X with distribution function F(t) satisfying F(0) : 0 and a survival function F(t): 1-F(t). This variable is said to be New Better than Used of specified age t$_{0}$ if F(x+ t$_{0}$)$\leq$F(x).F(t$_{0}$) for all x$\geq$0 and a fixed t$_{0}$. We propose the test for H$_{0}$ : F(x+t$_{0}$)=F(x).F(t$_{0}$) for all x$\geq$0 against H$_1$: F(x+t$_{0}$) $\leq$ F(x).F(t$_{0}$) for all x$\geq$0 when the specified age to is unknown but can be estimated from the data when t$_{0}$=ζ$_{p}$, the pth percentile of F. This test statistic, which is based on the normalized spacings between the ordered observations, is readily applied in the case of small sample. Also, our test is more simple than Ahmad's test (1998). Finally, the performance of our test is presented.our test is presented.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.387-394
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• 2002

This study was conducted to compare an econamical efficiency of a recommended rate of fertilizer with the criterion of the sustainable agriculture direct income support system(SADISS). Red pepper was cultivated with different fertilizer application levels of the standard amount of fertilizer for red pepper(SAFR), fertilizer recommended by soil testing for red pepper(FRST) and decrement of 20, 40, 60 and 80 percent of fertilizer recommended by soil testing for red pepper(DFRST 20, 40, 60, 80) and that of farmer's habitual practies fertilization (FHPF). The changes by different levels of applied fertilizer was compared with those of SADISS. The results were summirized as follows: No yield difference was found among the FHPF, SAFR, FRST and DFRST20, but yield decrease in FRST40, 60 and 80. T-N, $P_2O_5$ and $K_2O$ in FHPF were 24, 9 and 53 percent respectively, and it were the lowest ones among the treatments. Fertilizer efficiency of red pepper was decreased with application rate of fertilizer. Fertilization ratio of N and P in DFRST(40, 60, 80 percent) was not sufficiency for red pepper. Economical efficiency of FRST and DFRST20 showed sufficiently in comparison with FHPF. Therefore, it could be possible that FRST and DFRST20 were recommended as methods for SADISS in red pepper cultivation.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.51-55
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• 1985

Dried black soybeans were soaked in water at the temperature range of $4^{\circ}C{\sim}100^{\circ}C$ and in salt or sugar solution at $100^{\circ}C$ in order to investigate their effects on the cooking ratio and diffusion property of color pigments. As the temperature increased, the equilibrated absorbance at 490nm of soaking water after 120min was linearly increased. The activation energy for diffusion of color pigments were found to be 4.23 Kcal/mole at the range of $60^{\circ}C{\sim}100^{\circ}C$ and 8.31 kca1/mo1e at $4^{\circ}C{\sim}60^{\circ}C$. The cooking ratio, % cooked beans after heating, of black soybeans were more affected by the salt concentration that of sugar. Both concentrations reduced the cooking ratio as they increased. The sorption isotherm of Kongjaban showed a quite different curves between the storage at $4^{\circ}C$ and $25^{\circ}C$. The sorption and desorption rates during storage could be represented by the equation of $log({\frac{dw}{dt}}{\times}10^3))=alogt+logb$ with a very high correlation.

• International Area Studies Review
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• v.13 no.3
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• pp.287-308
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• 2009

This article examines the distributional characteristics of the return of Chinese stock market indices. The majority of previous empirical researches have tended to focus upon the simple stock market index. However, this study focuses on the four indices which represent the characteristics of each stock market index. The empirical findings indicate that the returns of the four chinese indices are not normally distributed at conventional levels. The Ljimg-Box -statistics indicate the returns of the index of A shares are not serially autocorrelated. However, the returns of the index of B shares are serially autocorrelated. The empirical findings also indicate returns of the four chinese indices are not serially autocorrelated. The statistics of Regression Specification Error Test and ARCH indicate the returns of all four indices are not serially linear. The findings also indicate that E- GARCH model is the most fittest model for the returns of the four chinese indices and the forecast error can be reduced by using student t distribution rather normal distribution.

• Korean Journal of Ichthyology
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• v.35 no.1
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• pp.10-19
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• 2023

This study aimed to examine the early life history of Trident goby (Tridentiger brevispinis) by observing their egg development and juvenile fish morphology. The average size of mature eggs was 1.13~1.41 (1.30±0.07) mm (n=30), and 0.70~0.86 (0.79±0.04) mm (n=30) in long diameter and short diameter, respectively. The incubation period at 24±1℃ ranged from 167~228 h. The newly hatched larvae measured 2.31~2.78 (2.51±0.18) mm (n=30) in total length (TL), and their mouth and anus were not yet open. At 3 days after hatching, the preflexion larvae reached 2.84~3.10 (2.98±0.10) mm in TL, where in their yolk absorption was complete and their mouths began to open. At 19 days after hatching, the larvae reached the flexion stage, measuring 4.02~4.62 (4.36±0.19) mm in TL. The tip of their notochord was bent upward. At 30 days post-hatching, the larvae reached the postflexion stage, measuring between 5.04~6.36 (5.76±0.51) mm in TL, with the tip of the caudal fin bent at 45°. After 54 days, the larvae had reached the juvenile stage, measuring between 7.43~9.84 (8.48±0.90) mm in TL, and were differentiated by their constant number of fins (6 first dorsal, 12 second dorsal, 11 anal, and 10 ventral fins). This study found that T. brevispinis had larger fertilized eggs and a greater number of myotomes in hatching larva than similar species. Additionally, the distribution of melanophores in T. brevispinis was distinct from that in other similar species, making it easy to distinguish them morphologically.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.17-25
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• 2009

The goal of this study is to develop Logistic regression model by accident location(entry section, exit section, inside intersection and pedestrian crossing section). Based on the accident data of Chungbuk Provincial Police Agency(2004$\sim$2005) and the field survey data, the geometric elements, environmental factor and others related to traffic accidents were analyzed. Developed models are all analyzed to be statistically significant(chi-square p=0.000, Nagelkerke $R^2$=0.363$\sim$0.819). The models show that the common factors of accidents are the traffic volume(ADT), distant of crossing and exclusive left turn lane, and the specific factors are the minor traffic volume(inside intersection model) and U-turn of main road(pedestrian crossing model). Hosmer & Loineshow tests are evaluated to be statistically significant(p$\geqq$0.05) except the entry section model. The correct classification rates are also analyzed to be very predictable(more than 73.9% to all models).

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.261-264
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• 2001

Cytotoxicity and antibacterial activity of preservatives were examined. Fibroblast cell L929 was used for cytotoxicity experiment and Pseudomonas aeruginosa A TCC27853, Staphylococcus aureus ATCC25923. Trichoderma reesei ATCC6967 were used for antibacteria and antifungi. Benzalkoniumchloride(BAK) as synthetic preservative and chitosan as natural preservative were used. Minimum inhibitary concentration (MIC) of BAK was 0.1 % for P. aeruginsa and 0.001% for S. aureus and 0.1 % for T reesei MIC of chitosan was 2% for P. aeruginosa and 1 % for S. aureus.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.774-784
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• 2011

The purpose of this study, which was conducted as a part of investigations for vitalizing the School Sheriff system proposed as a means to prevent school violence and promote school safety, was to survey recognition of elementary school parents toward the School Sheriff system and present an improvement scheme for the system. For the study, we selected as the research object a set of parents whose children attended schools with School Sheriffs and then sampled 200 parents out of them with cluster random sampling, before analyzing 189 finally. Validity of the questionnaire is verified by expert council and factorial analysis, and reliability by reliability analysis. Statistical means including chi-square test, t-test and F-test are used. The result of the study as follows : First, necessity of the School Sheriff system varies by individual characteristics. Second, recognition toward the system itself varies by individual characteristics. Third, recognition toward the role that should be played by School Sheriffs varies by individual characteristics. Fourth, there is a difference in perceiving the role and activity of School Sheriffs, Fifth, whether the system helped improving school safety varies by individual characteristics. Sixth, the satisfaction from the School Sheriffs.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.354-365
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• 2013

The purpose of the study was to develop the home fall prevention checklist for community-dwelling older adults. And the validity and reliability of the checklist were tested. The preliminary questions were developed through content validity by twenty experts using the CVI(Content Validity Index). Following the establishment of content validity, 52 items of the checklist were developed. Responses of 299 community-dwelling older adults were analyzed to further establish both reliability and validity of the checklist. Reliability using cohen's kappa coefficient and test-retest reliability(rate of concordance(%)), and construct validity using known-group comparison technique were tested. 51 items were over 0.80 in the cohen's kappa coefficient of the checklist, 45 items were over 80.0% in test-retest reliability. Construct validity was established by known-group comparison(t=3.50, p=.001). Validity and reliability of the checklist were confirmed. This checklist will help further studies to develop more safe environment to prevent falls.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.149-153
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• 2001

This study was performed to examine the cytotoxicity and antimicrobial activity of synthetic or natural preservative. Fibroblast cells L929 were used for cytotoxicity test and Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Trichoderma reesei ATCC6967 were used for antibacterial and antifungal activities. Benzalkonium chloride(BAC) as a synthetic preservative and chitosan as a natural preservative were used for this study. Minimum inhibitory concentration(MIC) of BAC was 0.1~0.01% for P. aeruginosa and 0.001~0.0001% for S. aureus and 0.1~0.01% for T. reesei, MIC of chitosan was 2% for P. aeruginosa and 1I % for S. aureus. This study suggest that chitosan might be useful as an eyedrop.