• Journal of Korea Water Resources Association
• /
• v.46 no.4
• /
• pp.401-412
• /
• 2013

Water footprint of a product and service is the volume of freshwater used to produce the product, measured in the life cycle or over the full supply chain. Since water footprint assessment helps us to understand how human activities and products relate to water scarcity and pollution, it can contribute to seek a sustainable way of water use in the consumption perspective. For the introduction of WFP scheme, it is indispensable to construct water inventory/accounting for the assessment, but there is no database in Korea to cover all industry sectors. Therefore, the aim of the study is to develop water footprint inventory within a nation at 403 industrial sectors using Input-Output Analysis. Water uses in the agricultural sector account for 79% of total water, and industrial sector have higher indirect water at most sectors, which is accounting for 82%. Most of the crop water is consumptive and direct water except rice. The greatest water use in the agricultural sectors is in rice paddy followed by aquaculture and fruit production, but the greatest water use intensity was not in the rice. The greatest water use intensity was 103,263 $m^3$/million KRW for other inedible crop production, which was attributed to the low economic value of the product with great water consumption in the cultivation. The next was timber tract followed by iron ores, raw timber, aquaculture, water supply and miscellaneous cereals like corn and other edible crops in terms of total water use intensity. In holistic view, water management considering indirect water in the industrial sector, i.e. supply chain management in the whole life cycle, is important to increase water use efficiency, since more than 56% of total water was indirect water by humanity. It is expected that the water use intensity data can be used for a water inventory to estimate water footprint of a product for the introduction of water footprint scheme in Korea.

• Korean journal of food and cookery science
• /
• v.27 no.5
• /
• pp.599-610
• /
• 2011

This study was performed to investigate the effect of water extracts from Namhae special crops (NSC) on improved serum lipid composition using rats fed a 1% cholesterol diet for 4 weeks. Male Wister rats (200-210 g) were divided into six groups: Normal cholesterol diet group (Normal), 1% cholesterol diet group (Control), 1% cholesterol and NSC water extract powder supplemented groups, including, turmeric (Tu-EP), cactus (Ba-EP), aloe vera (Al-EP) and asparagus (As-EP). No significant differences were observed for food intake or body weight gain between the control and experimental groups. However, food efficiency ratio (FER) was the lowest in the As-EP group. The serum levels of total cholesterol and triglycerides in the NSC water powder extract supplement groups were lower than those in the control group. The serum high density lipoprotein (HDL)-cholesterol content in the Tu-EP group was higher than that in the other experimental groups. Very low density lipoprotein (VLDL)-cholesterol content in the As-EP group was similar to that in normal group. Furthermore, the VLDL content in the Al-EP group was lower than that in the normal group. Serum antioxidant activity by TBARS level and DPPH radical scavenging were significantly higher in the Ba-EP group than that in the control group. Hepatic total cholesterol and lipid content in the Al-EP group decreased significantly compared to that in the control group. These results suggest that the NSC water extract may reduce serum cholesterol and prevent oxidative stress by stimulating antioxidative systems in rats fed a 1% cholesterol diet.

• Journal of the Korea Concrete Institute
• /
• v.23 no.6
• /
• pp.711-722
• /
• 2011

Beam-column gravity or Intermediate Moment frames subjected to unexpected large displacements are vulnerable when no seismic details are provided, which is typical. Conversely, economic efficiency of those frames is decreased if unnecessary special detailing is applied as the beam and column size becomes quite large and steel congestion is caused by joint transverse reinforcement in beam-column connections. Moderate seismic design is used in Korea for beam-column connections of buildings with structural walls, which are to be destroyed when the unexpected large earthquake occurs. Nonetheless, performance of such beamcolumn connections may be substantially improved by the addition of steel fibers. This study was conducted to investigate the effect of steel fibers in reinforced concrete exterior beam-column connections and possibility for the replacement of some joint transverse reinforcement. Ten half-scale beam-column connections with non-seismic details were tested under cyclic loads with two cycles at each drift up to 19 cycles. Main test parameters used were the volume ratio of steel fibers (0%, 1%, 1.5%) and joint transverse reinforcement amount. The test results show that maximum capacity, energy dissipation capacity, shear strength and bond condition are improved with the application of steel fibers to substitute transverse reinforcement of beam-column connections. Furthermore, several shear strength equations for exterior connections were examined, including the proposed equation for steel fiber-reinforced concrete exterior connections with non-seismic details.

• Journal of the Korean earth science society
• /
• v.23 no.4
• /
• pp.357-368
• /
• 2002

In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.

• The Korean Journal of Financial Management
• /
• v.22 no.1
• /
• pp.71-91
• /
• 2005

The object or this paper is to analyze the rollover effect on KOSPI 200 index option prices. Especially we analyze the implied volatilities of the options that became the near maturity options as the old one expired. For this analysis, a panel data of KOSPI 200 Index Option Prices from year 1999 to year 2001 were used, and following results were obtained. First, after controlling for the underlying index returns, strike prices and other pricing factors, the call option prices tend to decrease while the put option prices tend to increase during the week of expiry. Second, if one concentrates on the daily price changes, call option prices tend to go up on Thursday (as the old options expire), and then experience a price decrease on the following day, while the reverse is true for the put options. These results imply that the option prices are affected by some of the market micro-structure effects such as whether the option is the near maturity option. We conjecture that the reason for this is related to the undervaluation of KOSPI 200 futures. The results from this paper have implications on the timing of option trades. If one wants to buy put options, and/or sell call options, he has better off by executing his intended trades before the old options expire. On the other hand, if one wants to buy call options, and/or sell put options, hi has better off by executing his intended trades after the expiry.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.1
• /
• pp.162-171
• /
• 2014

As the foodservice industry is labor intensive, the efficient management of human resources is an essential element for improving operational efficiency. This study was designed to investigate the performance level of human resource management in self-operated school foodservices and to examine the relationship between human resource management, organizational commitment, and productivity. Whether these factors rated differently by employment and job types was also examined. Data were collected through questionnaires distributed to 60 dieticians and 240 cooks in Seongnam and Yongin. Frequency analysis, factor analysis, the t-test and multiple regression analysis were tested using Minitab. Human resource management practices rated highly in the dimension of employee training (3.51), followed by working environment (3.39), and turnover management (3.37). In contrast, reward management (1.73) and working condition (1.56) received the lowest score. Organizational commitment scored 3.65 points, and showed that dedication (3.82) was the highest score; however, self-esteem (3.50) was the lowest score. For human resource management, there were significant differences between employment types as full time workers (3.85) rated management more highly than part-time worker (3.43). Overall productivity was fairly high, especially in high school foodservices. Only the performance appraisal had an influence on organizational commitment (${\beta}$=0.292, P<0.05). Productivity was positively correlated with human resource management (r=0.432, P<0.001) and organizational commitment (r=0.36, P<0.01). In conclusion, school foodservices need to establish objective performance standards, and increase employee morale by enhancing reward systems and working conditions. In particular, irregular employees require training with job performance standards and given a proper reward program, depending on their performance, to improve organizational commitment.

• Journal of The Korean Association For Science Education
• /
• v.5 no.1
• /
• pp.49-61
• /
• 1985

In this study, I compared and analyzed the new and old secondary school science textbooks to find the charateristics of them and the differences between them. The results of the study are the following. Major concepts in the new textbook are almost similar to those in the old one. The-new textbook reinforces the functions of the introudction and checking the result of learning, and presents more and diverse learning materials and reduces the degree of learning difficulty by omitting the several abstract knowledges and mathematical formulas which can be understood through formal operational thinking. The results show that the new textbook is more effective in arousing student's interest and curiosity there fore it increases the efficiency of learning. But the new textbook is less suitable for inquiry because it is mainly composed of explanation and fact rather than experiment and observation. I think that this is the result from the actual approach to the real conditions of school when the curriculum was reformed and the new textbook was written.

• Journal of Aquaculture
• /
• v.12 no.1
• /
• pp.47-56
• /
• 1999

Denitrification by anaerobic bacteria is one of the most common processes of removing nitrate from recirculating aquaculture systems. This process is affected by many factors such as external carbon sources, hydraulic retention time (HRT), and $COD/NO_3-N$ ratio. Although external organic carbon sources are essential for the denitrification process, these also contribute to increase dissolved organic carbon concentration in recirculating aquaculture systems. So these external organic carbons must be removed from the systems. This study was conducted to find out the optimum operating conditions for the removal of external organic carbons in a submerged denitrification biofilter. Combinations of two external carbon sources (glucose and methanol), two HRT (4- and 8-hour), and four different C:N ratios (3, 4, 5, and 6) were used in this experiment. The removal efficiencies of organic carbon sources at 8-hour HRT were always better than those at 4-hour's (P<0.05). Maximum removal efficiencies were achieved when C:N ratio was 5 in both glucose and methanol. The removal efficiencies of methanol were always better than those of glucose. The maximum removal efficiencies of glucose and methanol were 76.5% and 84.0%, respectively and the removal rates were 223.5 $g/m^2/day$ and 247.1$g/m^2/day$. The maximum removal rates of glucose (290.9 $g/m^2/day$) and methanol (355.6 $g/m^2/day$) were achieved at 4-hour HRT and 5 C:N ratio. But the concentrations of SCOD in the effluent of both glucose ($52.5 mg/\ell$) and methanol ($40.9 mg/\ell$) were too high for rearing fish. Therefore, the optimum operating conditions for the removal of external carbon in a submerged denitrification biofilter were 8-hour HRT and 5 C:N ratio. And methanol showed better efficiency as an external carbon sources.

• Culinary science and hospitality research
• /
• v.19 no.3
• /
• pp.1-17
• /
• 2013

This research was to examine the effects of downsizing kitchen employees in a hotel on their job efficiency and to verify differences in the individuals' behavior characteristics according to DISC behavior types in this causal relationship. Through SPSS 17.0 program, factor analysis, reliability analysis, correlation analysis, and multiple regression analysis were conducted on 200 samples secured for an empirical research. Two factors for the downsizing items and two factors for the items related to job attitude were extracted. Hypothesis 1 was that the downsizing within a hotel has significant negative (-) effects on job attitude. As a result of the verification, it was found that downsizing had significantly negative effects on the job attitude of cooking employees as factors for organizational commitment in employment circumstances (${\beta}$=-.256), and employment anxiety (${\beta}$=-.258), and as factors for job satisfaction in employment circumstances (${\beta}$=-.319), and employment anxiety (${\beta}$=-.174). Hypothesis 2 was that the downsizing according to DISC behavior types has significant negative (-) effects on job attitude. As a result of the verification, it was found that in the organizational commitment factors, the dominance type (D) was more influenced by employment anxiety (${\beta}$=-.435) than by any other types, and the conscientiousness type (C) was not influenced by organizational commitment. In the job satisfaction factors, the steadiness type (S) was more influenced by the changes in employment circumstances (${\beta}$=-.414) than by other types, and the dominance type (D) was not influenced. Based on the results of this research, it can be said that hotel's downsizing strategies influence job attitude such as organizational commitment and job satisfaction of cooking employees, and that there are differences in the influences according to the individuals' behavior types of kitchen employees.

• Sleep Medicine and Psychophysiology
• /
• v.12 no.1
• /
• pp.27-31
• /
• 2005

Objectives: We attempted to compare the performance of 2 commercially available actigraphies with focus on sleep parameters, using polysomnography as standard comparison tool. Methods: Fourteen normal volunteers (5 males and 9 females, mean age of $28{\pm}4.6\;years$) participated in this study. All the participants went through one night of polysomnography, simultaneously wearing 2 different kinds of actigraphies on each wrist. Polysomnographic and actigraphic data were stored, downloaded, and processed according to standard protocols and then statistically compared. Results: Both $ActiWatch^{(R)}$ and $SleepWatch^{(R)}$ tended to overestimate the total sleep time, compared to the polysomnography. $SleepWatch^{(R)}$ tended to underestimate the sleep latency. The two actigraphs and the polysomnograph did not show significant difference of sleep efficiency, when compared with one another. In addition, all of the sleep parameters from the instruments showed linear correlations except in $SleepWatch^{(R)}'s$ sleep latency. The sleep parameters from the two actigraphs did not show much noteworthy difference, and linear relationships were found between the sleep parameters from the two actigraphs. There was no significant distinction in the results of the two different actigraphs. Conclusion: The results of two actigraphies can be used interchangeably since the sleep parameters of the two different actigraphies do not show significant differences statistically. Overall, it is not legitimate to use actigraphy as a substitute for polysomnography. However, since sleep parameters except sleep latency show linear correlations, actigraphy might possibly be used to follow up patients after polysomnography.