• Korean journal of applied entomology
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• v.57 no.2
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• pp.97-104
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• 2018

The larva of the white-spotted flower chafer, Protaetia brevitarsis seulensis (Coleoptera: Cetoniidae), is known to have important medicinal properties, such as anti-cancer activity. However, the consumer market for the larvae is depressed because of its high production cost which needs to be reduced. This study was carried out to evaluate two spent mushroom substrates as food source for chafer larvae to improve the productivity and reduce production cost. The larvae were fed with spent substrates of king oyster mushroom (Pleurotus eryngii) (P-SMS) and shiitake mushroom (Lentinula edodes) (L-SMS), with a control of fermented oak sawdust. Effects of the diets on the development of P. brevitarsis seulensis and contents of minor nutrient components in the larvae produced were examined. In the P-SMS diet, the larval rearing period was shorter at 16.2 days, while the rate of larval weight gain and the cocoon weight were higher at 156.3% and 4.1 g, respectively, than that in the L-SMS diet. The pupation rate was 100% and the adult emergence was higher at 93.3% in the P-SMS diet than in the L-SMS diet with no difference to the control diet. In the P-SMS diet, the total nitrogen content during rearing was higher at 10.28% and the minor nutrient component, particularly Fe (145.8 mg/kg), was higher than that in other diets. The oviposition preference of adults showed no significant difference among the diets. Economic analysis showed that P-SMS costs approximately 667,960 Won less per 100 kg of larvae produced, compared to that of the control diet.

• Sleep Medicine and Psychophysiology
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• v.10 no.2
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• pp.93-99
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• 2003

Objectives：Sleep loss and excessive daytime sleepiness may have serious consequences, including traffic and industrial accidents, decreased productivity, learning disabilities and interpersonal problems. Yet despite these adverse effects, there are few epidemiological studies on sleep loss and daytime sleepiness in the general population of Korea. This study investigates the number of people who suffer from sleep insufficiency, how much recovery sleep occurs on weekends, and the relationship between the amount of recovery sleep and daytime sleepiness. Methods：A total 164 volunteers, aged 20 and over, were recruited by advertisement. The subjects were workers and college students living in Seoul, Korea. Subjects were excluded if they were aged over 60；if they had medical, neurological, psychiatric or sleep disorders that could cause insomnia or daytime sleepiness；if they were not following a regular sleep schedule；if they traveled abroad during the study；or if they did not leave home to work or were shift workers. They were interviewed and given a sleep log to complete on each of 14 consecutive mornings. They also completed the Epworth Sleepiness Scale (ESS) at noontime on the last day of the second week. All statistical data were analyzed by t-test, $X^2$-test or ANOVA, using SPSS/PC+. Results：The results showed that the subjects woke up at 6：50 (${\pm}1$：16) on weekdays, 7：09 (${\pm}1$：29) on Saturdays, and 8：12 (${\pm}1$：39) on Sundays and holidays. They took more frequent and longer naps on Sundays than on weekdays and Saturdays. The mean sleep duration was 6h 35 min. on week nights, with a mean increase of about 1h on weekends. Only 9.1% of the subjects spent more than 8h in bed on week nights, with 67% spending less than 7h, and 49.4% reported recovery sleep of more than 1h on Sundays. The subjects who reported recovery sleep of more than 2h on Sundays, showed significantly more excessive daytime sleepiness than those who reported less than 30 min (F=2.62, p<.05). Conclusions：These findings suggest that sleep insufficiency and excessive daytime sleepiness are relatively common in Korea, and that the people who get insufficient sleep on weekdays try to compensate for sleep loss with oversleeping and daytime napping on Sundays and holidays. It appeared that daily sleep insufficiency had a cumulative effect and increased daytime sleepiness.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.231-236
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• 2007

A feeding trial was conducted to study the effects of dietary supplement of fermented clay mineral (FCM) on the growth performance and immune stimulation in broiler chickens. A total of 36,800 broilers, (of) Ross strain-208, were randomly allotted into 2 experimental (diet) groups. Control group was fed the basal diet (corn-soybean meal based), and treatment group was fed the natural clay mineral that was fermented with aboriginal microorganisms at $37^{\circ}C$ for 72 h. Feed and water were provided ad libitum throughout the experiment for 5 weeks of experimental feeding period. Daily weight gain of treatment group fed 0.3% fermented clay mineral was significantly increased in comparison with control group. Feed intake of treatment group was significantly increased 21.4% (p<0.05), and feed efficiency was also increased 2.7% compared to control group. Especially, growth rate and production index of treatment group were significantly higher as much as 4.4% and 4.8%, respectively, than those of control group (p<0.05). By the feeding of dietary 0.3 % FCM, the antibody productions against Newcastle Disease and Infectious Bursal Disease antigens were shown to increase 13.8 % and 15.7 %, respectively, more than control group chickens. From these results, it appears that the supply of fermented clay mineral at 0.3 % level in the broiler chicken diet could enhance the growth performance and immune stimulation of broiler chickens.

• Korean Journal of Poultry Science
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• v.35 no.1
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• pp.63-69
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• 2008

The objective of this study was to investigate the effect of restricted feeding to laying performance and egg quality in brown layers. A total of 1,080 brown layer chicks were divided into three treatments; conventional feeding (ad libitum) and two restricted feedings (80% of conventional diet) for 70 weeks. One of restricted feeding started from six to eighteen weeks of age, and the other started from twelve to eighteen weeks of age. Diets were formulated by NRC (1994) recommendation. Overall laying performance and feed intake were the highest in $6{\sim}18 wk$ restricted group. But there was no significant difference among treatment group (P>0.05). Feed intake was higher in $6{\sim}18 wk$ restricted group during maximum production (P<0.05), but there was no difference between treatments after the peak. Egg quality tended to decreased by aging, but there was no significant difference among the treatments (P>0.05). The result of present study indicated that restricted feeding in rearing period of layers is beneficial to improve egg productivity and to reduce feed cost.

• Korean Journal of Poultry Science
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• v.35 no.1
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• pp.79-84
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• 2008

This study was conducted to investigate the effects of feeding herb extract (HE) on productivity, intestinal microflora and blood component profile in broiler chickens. A total of three hundred twenty, 1-d-old male chicks (Ross) were divided into 4 treatments with 5 replicates, 16 birds per replicate. Dietary treatments consisted of four diets; the corn-soybean based control diet, the diet containing HE 0.1%, the diet containing HE 0.2%, and the diet containing HE 0.4%. The Control diet contained 3,100, 3,100, 3,200 kcal/kg ME and 22%, 20%, 18% CP for starter ($0{\sim}2 wk$), grower ($3{\sim}5 wk$), and finisher ($6{\sim}7 wk$) periods, respectively. There were no significant differences in feed intake and BW gain among treatments in starter period. In grower period, the BW gain of HE 0.2%, and HE 0.4% were significantly higher (p<0.05) compared to Control. The 7-wk BW gain of HE 0.2% was significantly higher than Control (p<0.05). The feed intake tended to increase in HE 0.1%, but no difference was detected in feed conversion ratio among treatments. No significant differences were found in blood total cholesterol, triglyceride, HDL-cholesterol, glucose, total protein, and albumin among treatments, but total cholesterol in HE 0.4% decreased significantly as compared with Control. The cfu of Lactobacillus spp., yeast, and E. coli in the guts of chickens fed HE were not different form each other, but tended to increase as compared with Control.

• Journal of Ginseng Research
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• v.33 no.3
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• pp.206-211
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• 2009

In order to investigate the effects of elicitors on the growth and ginsenoside biosynthesis of ginseng hairy roots, we treated Panax ginseng hairy root with various concentrations of Haliotidis concha according to different time course. Haliotidis concha supplement increased the biomass and ginsenoside accumulation at 10 mg/L concentration. The growth rate of hairy root under a lighter concentration was greater than hairy root treated with a denser concentration. The highest content and productivity of ginsenosides appeared at 2 weeks after the treatment of 10 mg/L Haliotidis concha. The gene expression of squalene synthase, squalene epoxidase, dammarenediol synthase, cycloartenol synthase, $\beta$-amyrin synthase in hairy roots of ginseng were examined by RT-PCR. The Haliotidis concha treatment resulted in the obvious accumulation of the mRNA of triterpene biosynthesis in Panax ginseng hairy root as compared with the control. In this study, Haliotidis concha acts as a kind of elicitor for the production of ginsenosides.

• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.191-200
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• 2012

This study was conducted to investigate the effects of application of cattle slurry on forage productivity and environmental pollution in rice paddy land. Cropping systems used in this study consisted of two designs, such as whole crop rice applied with standard fertilizer (MWRS) and whole crop rice applied with cattle slurry (MWRC). The field experiments were conducted on the clay loam at Backsanmyun, Kimje, Chunlabukdo province in Korea for three years (May 2006 to Apr. 2009). This study was arranged in completely randomized design with three replicates. The yield of dry matter of whole crop rice in MWRS was similar as compared with that of MWRC. The contents of crude protein of whole crop rice in MWRS significantly increased as compared with those of MWRC (P<0.05). However, the contents of acid detergent fiber (ADF), neutral detergent fiber (NDF) and total digestible nutrients (TDN) of whole crop rice were hardly influenced by cattle slurry application. The pH, and contents of T-N, $P_2O_5$ and organic matter (OM) in soil samples collected at the end of the experiment increased as compared with those at the beginning of the experiment. After the end of experiment, the concentrations of exchangeable cations (Ca, Na, Mg and K) in soil samples collected at the end of the experiment were remarkably higher than those at the beginning of the experiment (P<0.05). The concentrations of $NO_3$-N and $NH_4$-N in discharge water in MWRS, MWRC and DWBRC were higher in 2008 than those in 2007. But the concentration of $PO_4$-P in discharge water was hardly influenced by the cropping system during experimental period. The concentrations of $NO_3$-N, $NH_4$-N and $PO_4$-P in leaching water were hardly influenced by application of cattle slurry.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.215-221
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• 2019

This study investigated the effects of various stocking densities on the growth performance of Korean native ducks. Twelve hundred day-old ducklings were reared for 50 days in a duck house (windowless, plastic wire-floor pen). Two weeks later, 852 of these ducks (350±30 g) were selected for at least 80% uniformity per stocking treatment (six treatments, four replications/treatment, depending on a stocking density of 4~9 birds m^-2). Experimental diets were corn-soybean-based and broiler ducks were grouped based on age [0~21 days of age (CP 21%, ME 2,900 kcal/kg) and 21~50 days of age (CP 17%, ME 3,100 kcal/kg)]. Body weight (BW) did not significantly differ among different aged treatment groups (P>0.05); however, uniformity decreased with higher stocking densities (P<0.05). Feed intake and feed conversion ratio of ducks aged 42~50 days significantly decreased in the T4-6 treatments compared with the T1-3 treatments (P<0.05). In all experimental periods, BW gain was not significantly different among treatments, but feed intake decreased significantly as the stocking density increased (P<0.05), and feed conversion ratio was significantly different among six treatments with stocking density (P<0.05). In conclusion, we found that the stocking density of Korean native ducks in a plastic wire-floor pen was approximately 7 birds m^-2 in consideration of productivity and uniformity.

• Journal of Sericultural and Entomological Science
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• v.23 no.2
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• pp.37-49
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• 1982

Larvae of the silkworm (Bombyx mori L.) were reared during the 5th instar on the four kinds of artificial diets on the basis of the different amounts of soybean meal used as the protein source. In this experiment it was shown that the various levels of protein in the diet affected not only the growth and silk production but the digestibility of the diet. haemolymph protein and uric acid excretion. The results obtained are summarized as follows; 1. By an increase of the level of protein in the diet the apparant digestibility was increased. but the protein digestibility was comparatively decreased. 2. Larval body weight increment was not observed by the 3rd day of the 5th instar, but was increased from the 4th day as the level of protein was increased in the diet. 3. After the 3rd day of the 5th instar, protein content in the hemolymph was increased steeply by an increase of the protein content in the diet. However, the percentage of hemolymph protein to the ingested protein was decreased from the 2nd day of the 5th instar and increased more or less after the 4th day. 4. An increase of the uric acid excretion was observed as the content of protein in the diet was increased but the pattern of the uric acid excretion was different between high and low-protein diet. However, the percentage of the uric acid excretion to the ingested protein and to the hemolymph protein were both decreased steeply after the 2nd day of the 5th instar. 5. It was also evident that the high-protein diet increased the cocoon productivity. 6. It showed that the feed efficiency for body weight increment and silk formation was high by an increase of the level of protein in the diet, but the protein efficiency was not.

• Asia pacific journal of information systems
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• v.19 no.2
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• pp.195-221
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• 2009

According to an industry report, a large number of organizations have invested in Organizational Information System(OIS) in the past few years. Several research results indicate that successful investments in OIS lead to productivity enhancement, while failed ones result in undesirable consequences such as financial losses and dissatisfaction among employees. In spite of huge investments, however, many organizations have failed in achieving the hoped-for returns from OIS. Thus, understanding user acceptance, adoption, and usage of new IS(Information Systems) is an important issue for IS practitioners. Indeed, study of the user acceptance of new information system has been one of the most important research topics in the contemporary IS literature. Several theoretical models are tested to examine 'user acceptance' and 'usage behavior' in IS context. While many research models incorporate 'ease of use' or 'usefulness' as important factors in explaining user acceptance, Technology Acceptance Model(TAM) has been one of the most widely applied models in user acceptance and usage behavior. Even in recent IS studies that employ theories of innovation diffusion in the area of IS implementation, a major focus has been on the user's perception of information technologies. In this research, we study 'voluntariness' as an important factor in IS acceptance by users. Voluntariness is defined as "the degree to which the use of the innovation is perceived as being voluntary, or of free will" When examining the diffusion of accepting OIS, a thoughtful consideration should be given to 'perceived voluntariness.' Current article has following research questions: 1) What models are appropriate to explain the success of OIS? and 2) How does the 'voluntariness' affect the success of OIS? In order to answer these questions, a research model is proposed to describe the detailed nature of association among three independent variables (IT usage level, task interdependency, and organizational support), a mediating variable (IS usage), a dependent variable (perceived performance), and a moderating variable(perceived voluntariness). The central claim of this article is that organizations hardly realize expected returns from OIS investments unless perceived voluntariness is effectively managed after operating OIS. As an example of OIS in this study we have selected the Intranet of Republic of Korea Air Force (ROKAF). ROKAF has implemented the Intranet in an attempt to improve communication and coordination within the organization. To test our research model and hypotheses, survey questionnaires were first sent out to 400 Intranet users. With the assistance of ROKAF, Intranet users were initially identified among its members, and subjects were randomly drawn from the pool. 377 survey responses were finally returned. The unit of measurement and analysis in this research is a personal level. Path analysis based on structural equation modeling was used to test research hypotheses. Construct validity represents accordance between the theoretical base concept of constructs and its measurement items. Tests for the reliability and discriminant validity are accepted, thus verifying our survey instrument. In this research, we have proposed a conceptual framework to highlight the importance of perceived voluntariness after organization deploys OIS. The results of our analysis present several key finding. First, all three independent variables (IT usage level, task interdependency, and organizational support) have significant effects on IS usage, which will eventually improve performance. Thus, IS usage plays a mediating role between antecedent variables (IT usage level. task interdependency, and organizational support) and performance improvement. Second, the effect of the task dependency was the highest for IS usage among the three antecedent variables. This is highly plausible since one of the Intranet's major capabilities is to facilitate communication among members within an organization. Accordingly, we conclude that the higher the task dependency, the higher Intranet usage. The effect of user's IT usage level was the second, while the effect of the organizational support was the third. Finally, the perceived voluntariness plays a pivotal role in enhancing perceived performance in personal level after launching the Intranet. Relationships among investigated variables were significantly different between groups with a high level and a low level of voluntariness. The impact of the Intranet usage on the performance was greater in the higher level voluntariness group than in the lower one. For the lower level voluntariness group, the user's IT usage had the highest effect on the Intranet usage among the three antecedent variables. In short, our study suggests that the higher the perceived voluntariness is the more IS usage will be. Perceived voluntariness was found to have a moderating effect on the relationships among user IT usage level, task interdependency, IS usage, and perceived performance, supporting all the hypotheses on the moderating effect. Most of all, user IT usage level has the strongest influence on IS usage, indicating that users with superior IT usage are more likely to enjoy a high level of perceived performance.