• Journal of Korean Society of Water and Wastewater
• /
• v.12 no.4
• /
• pp.86-96
• /
• 1998

In this study, an intermittently aerated activated sludge process, modified process from conventional activated sludge process, was developed to treat high strength swine wastewater, which has been blamed as major pollutant for stream pollution. Therefore, the optimum cycle for oxic and anoxic period, SRT, and OLR were studied as design parameters. The effects of different time interval for oxic and anoxic period on nitrification and denitrification were examined by operating two reactors with 60/60min and 60/90min as oxic/anoxic period. Although the reactor with 60/60min showed complete denitrification of $NO_x-N$ generated during oxic period, the reactor with 60/90min showed incomplete nitrification due to the inactivity of nitrifier by accumulated $NH_3-N$ toxicity during anoxic period. Therefore, it is recommended to operate same interval for oxic and anoxic period. In order to determine the optimum cycle for oxic/anoxic period, four different reactors with 30/30, 60/60, 90/90 and 120/120min were examined. The reactor operation with 90/90min was optimum to get the most stable results in this study. However, the optimum cycle for oxic and anoxic period should be changed with characteristics of influent wastewater and operating conditions. According to lie operation results of three reactors with SRT of 15, 20 and 30days. The reactor with 2Odays SRT showed best removal efficiency of T-N. The optimum OLR would be $2.5Kg\;COD/m^3/day$ which showed the most stable nitrification and denitrification. Since characteristics of influent wastewater in the real system has a severe fluctuation, so it is very difficult to determine each interval for oxic and anoxic period. Therefore, ORP curves, describing the change of oxidation/reduction potential in reactor, can be used as a control parameter for automatic control of oxic and anoxic period. In other words, bending point (Nitrate Knee) of ORP curve during anoxic period could be used as a starting point of oxic period.

• Journal of Korean Academy of Nursing
• /
• v.28 no.2
• /
• pp.303-318
• /
• 1998

Cutaneous stimulation and distraction are independent nursing interventions used in various painful conditions, which is explained by gate control theory. This study was aimed at identifying the effect of cutaneous stimulation, distraction and combination of cutaneous stimulation and distraction on the reduction of intravenous injection pain levels of chemotherapy patients. Repeated measurement post test research design was used for one group. Fifty-three cancer patients who received intravenous chemotherapy regulary in outpatient injection rooms of D medical center and Y medical center in Taegu were studied from June 23, 1997 to July 12, 1997. First the intravenous injection pain level of the control period was measured. Second, the intravenous injection pain level of the experimental period using cutaneous stimulation was measured. Third, the intravenous injection pain level of the experimental period using distraction was messured. Fourth, the intravenous injection pain level of the experimental period using a combination of cutaneous stimulation and distraction was measured. The instruments used for this study were a visual analogue pain scale as subjective pain measurement and an objective pain behavior checklist. Analysis of data was done by use of repeated measure ANOVA, bonferni, t-test, and F-test. The results of this study were summerized as follows : 1) The first hypothesis that the subjective pain score of intraveneous injection pain in the experimental period with cutaneous stimulation will be lower than in the control period was rejected. 2) The second hypothesis that the objective pain behavior score of intravenous injection pain in the experimental period with cutaneous stimulation will be lower than in the control period was accepted(F=24.23, p=0.0001, Bornferni p<.05). 3) The third hypothesis that the subjective pain score of intraveneous injection pain in the experimental period with distraction will be lower than in the control period was rejected. 4) The fourth hypothesis that the objective pain score of intravenous injection pain in the experimental period with distraction will be lower than in the control period was accepted(F=24.23, p=0.0001, Bornferni p<.05). 5) The fifth hypothesis that the subjective pain score of intravenous injection pain in the experimental period with combination of cutaneous stimulation and distraction will be lower than in the control period was accepted(F=3.04, p=0.031, Bonferni p<.05). 6) The sixth hypothesis that the objective pain score of intravenous injection pain in the experimental period with combination of cutaneous stimulation and distraction will be lower than in the control period was accepted(F=24.23, p=0.0001, Bonferni p<.05).

• Journal of Animal Science and Technology
• /
• v.45 no.1
• /
• pp.23-32
• /
• 2003

Genetic parameters for growth and carcass traits were estimated on the basis of the data from 3,415 heads of Hanwoo bulls tested at Livestock Improvement Main Center. The data were divided into two groups : the first period group consisted of 1,592 heads of bulls tested in individual pens from 1986 to 1990 and the second period group consisted of 1,823 heads of bulls tested in group pens from 1991 to 1996. The testing period was from 6 to 18 months of age in the first period group and 10 to 22 months of age in the second period group. The average daily gains during 6 to 12 months and 12 to 18 months were 1.01kg and 0.77kg, respectively, in the first period group and 0.80kg and 0.95kg in the second period group, and the compensated growth appeared to have occurred in the second period group. The heritability of body weight at 12 months estimated was 0.37 during the first period and 0.47 during the second period. The heritability of body weight at 18 months was 0.29 during the first period and 0.33 during the second period. The heritability of average daily gain during 6${\sim}$12 months estimated was 0.26 for the first period and 0.33 for the second period. The heritability of average daily gain during 12${\sim}$18 months estimated was 0.11 for the first period and 0.22 for the second period. The heritabilities of body weights and average daily gains estimated tended to be higher in the second period than in the first period. The heritability of body measurements at 12 months during the first period estimated was 0.30 for withers height, 0.25 for rump height, 0.11 for thurls width and 0.13 for chest girth. The heritability of body measurments at 12 months during the second period was 0.53 for withers height, 0.44 for rump height, 0.36 for thurls width and 0.56 for chest girth. The heritabilites of withers height, rump height, thurls width and chest girth at 18 months of age were 0.40, 0.22, 0.12 and 0.21 during the first period and 0.45, 0.42, 0.42 and 0.35 during the second period, respectively. The heritability of carcass traits estimated during the first period was 0.11 for carcass weight, 0.24 for dressing percent, 0.25 for eye muscle area, 0.18 for backfat thickness and 0.21 for carcass length. The heritabilities of carcass weight, dressing percent, eye muscle area, backfat thickness, carcass length and marbling score during the second period estimated were 0.32, 0.52, 0.33, 0.51, 0.58 and 0.31, respectively. The genetic correlations between the first and second periods estimated were higher than 0.8 for chest girth at 12 months, rump height at 18 months, carcass weight and dressing percent, but were lower for other traits.

• Journal of the Korea Concrete Institute
• /
• v.17 no.2 s.86
• /
• pp.237-245
• /
• 2005

In this paper, the changes of the period of cold weather concrete in Korea with the elapse of age are discussed to investigate the influence of elapse of age on period of cold weather concrete. The climate data of Korean Meteorological Administration(KMA) ranging from 1971 to 2000 was used. The period of cold weather concrete was calculated by following the specification of Korea Concrete Institute(KCI), American Concrete Institute(ACI) and Architectural Institute of Japan(AIJ), respectively. Previous research by the authors used the climate dada of KMA from 1961 to 1990 and research conducted by Kim M.H. used the climate data from 1931 to 1980 were also compared with the period of present paper. According to the results, in present paper, the period of cold weather concreting by KCI was calculated about 95days on average and the period by ACI was 101 days on average and the period by AIJI was 92days on average. For the variation of the period with the elapse of time, the period of cold weather concrete by KCI and ACI in present paper was shortened by as much as 5${\~}$6days compared with that of previous paper 10years ago. However, the period of cold weather concreting by AIJ did not exhibit a marked reduction in the period compared with that of previous paper by the author. But the period by Kim following AIJ exhibited a decrease in the period compared to the period by present paper by as much as 3days. For regional influence, the period of cold weather concreting in southern part of Korea was found to be much shorter than those at northern part. This may be due to the rising of mean temperature caused by global warming effect.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.4
• /
• pp.91-105
• /
• 2019

Discrete-time Queueing models are frequently utilized to analyze the performance of computing and communication systems. The length of busy period is one of important performance measures for such systems. In this paper, we consider the busy period of the Geo/Geo/1/K queue with a single vacation. We derive the moments of the length of the busy (idle) period, the number of customers who arrive and enter the system during the busy (idle) period and the number of customers who arrive but are lost due to no vacancies in the system for both early arrival system (EAS) and late arrival system (LAS). In order to do this, recursive equations for the joint probability generating function of the busy period of the Geo/Geo/1/K queue starting with n, 1 ≤ n ≤ K, customers, the number of customers who arrive and enter the system, and arrive but are lost during that busy period are constructed. Using the result of the busy period analysis, we also numerically study differences of various performance measures between EAS and LAS. This numerical study shows that the performance gap between EAS and LAS increases as the system capacity K decrease, and the arrival rate (probability) approaches the service rate (probability). This performance gap also decreases as the vacation rate (probability) decrease, but it does not shrink to zero.

• Journal of the Korean Society of Costume
• /
• v.55 no.6 s.96
• /
• pp.38-50
• /
• 2005

A chronological classification of Sangbok(상복) and Sibok(시복) for officers in Joseon Dynasty is proposed in this paper. The classification results in four distinct periods according to the usage of Sangbok and Sibok as well as their colers and naming: 1) the mixed usage period, 2) the usage-differentiation period, 3) the name-differentiation period, and 4) name-reversal period. During the mixed usage period which lasted until the early 15th century, Sangbok and Sibok were used with no distinction. In the usage-differentiation period, the King Sejong first made a regulation on the use of colors of Dal-lyung according to the occasion and black colored uniforms were used only for daily cabinet meetings. In the 16th century, the names of Sangbok and Sibok began to be used distinctively: Sangbok for formal clothing in black color and Sibok for ordinary clothing in pink color This period is defined as the name-differentiation period in this paper. In the name-reversal period f·hick begun around the 17th century, the usages as well as the colors of Sangbok and Sibok are totally reversed because of some confusions of the understanding on the previous government publications. However, the distinction of formal clothing and ordinary clothing remained.

• Journal of Korean Elementary Science Education
• /
• v.31 no.4
• /
• pp.424-435
• /
• 2012

The purpose of this study was to analyze the geological terms used in the elementary school science curriculums from 1876 to present. We collected the data of geological terminologies based on what is being used in the revised 2007 national curriculum. In this study, data was divided into three periods according to political events, "The Modern Enlightenment Period (1876~1910)", "The Japanese Colonial Period (1910~1945)", and "The Current Curriculum Period (1945~present)". During the early modern enlightenment period, translated Chinese characters' terminologies by western scholars in Qing-China were used in science books. The late modern enlightenment period, we used many translated Japanese textbooks in schools, which naturally introduced the way that Japan's terminology is used. In the Japanese colonial period, Korean students had to study science subjects written in Japanese characters, so they had used Japanese terminologies of science. After the liberation of Korea from the Imperial Japan, there was an efforts to make new Korean terminologies of geology under the new current national curriculum. However, the terminologies used in Korean textbooks ended up using and borrowing the same way that the Japanese-Sino terms of science used later.

• Journal of the Korean Society of Costume
• /
• v.45
• /
• pp.41-54
• /
• 1999

The purpose of this thesis is to trace the development of cotton Early Chosun Period by examining the historical literary sources : such as production of cotton various uses of cotton trade with other countries The developement process of cotton fabrics during this period can be divided into three stages. The first stage which can be discribed as a settling period lasted 27 years from A.D. 1392 to 1418. In this stage cotton fabrics were just about to be used as fabrics for popular clothing. The second stage which can be discribed as a developmental period lasted 50 years from A. D.1418 to 1468. In this stage cotton fabrics were mainly produced in the southern parts of the country which are Kyungasng-Do, Choongcheng-Do and Jeunla-Do. And cotton fabrics were used not only by the common people but also by the royal family. The third stage, that is the last one was an extensive period and lasted from A.D.1469 to 1592. In this stage as the demand for cotton fabrics greatly increased the production from southern parts of the country fell in short of the supply needed. Therefore the production was extended to the northwestern parts. In addition cotton fabrics finally came to be used as money to value the goods.

• Korean Journal of Organic Agriculture
• /
• v.29 no.4
• /
• pp.507-521
• /
• 2021

The livestock farmers are producing under uncertainties such as Foot-and-Mouth Disease (FMD) and Free Trade Agreement (FTA). The purpose of this study is to strengthen the management capabilities of Hanwoo farmers to prepare them for the uncertainties just mentioned. To this end, this study was conducted to find the optimal rearing period in order to reduce the feed cost, which accounts for the largest portion of the operation cost of Hanwoo. Using the universal lattice model, 41,139 of 289,000 Hanwoo slaughter data from 2010 to 2019 were used for the FMD period and 246,605 heads for the general period. The results show that the maximum cutoff price of Hanwoo steer is 6,394,457 won at the 4th week of 27 months of age in general period, where as 6,242,752 won at the 2nd week of 26 months of age in the FMD period. Therefore, it is judged that it will be helpful for Hanwoo farms to maximize their business profits by slaughtering one month and two weeks earlier in the FMD period than in the general period. In addition, Hanwoo farmers need to break away from the conventional rearing method and improve their management efficiency through a more flexible rearing method.

• English Language & Literature Teaching
• /
• v.16 no.4
• /
• pp.107-131
• /
• 2010

The goals of the present study are two-fold: 1) to examine NNS teachers' needs for training period in improving their general communicative competence and classroom communicative competence, and 2) to explore the relationships of teachers' needs for the training period, and their current levels of general/classroom communicative competence and other background variables. Data was collected from seventy primary and secondary school English teachers (N=70) who participated in the six-month intensive teacher training program in South Korea. The teacher trainees responded to four questionnaires of 1) the self-diagnosis of their current levels of four language skills (L/S/R/W) in both general/classroom communicative competence, 2) the training period required to improve their general/classroom communicative competence for teaching both English and other subjects through English, 3) the period of their English teaching, and 4) the proportion of their English use in class. The data analysis has shown that there were the strong relationships between trainee needs for the training period and their teaching period, and the proportion of their English use in class. In terms of trainees' communicative competence, the significant relations of both their general/classroom communicative competence and their needs for the training period were found. Implications of the findings are discussed.