• Journal of Nutrition and Health
• /
• v.30 no.10
• /
• pp.1229-1243
• /
• 1997

The purpose of this study were to :(a) investigate meal costs, plate waste costs, and advantages/disadvantages of conventional /commissary foodservices and (b) compare the effectiveness of commissary foodservice systems with that of conventional systems. Questionnaires were developed and mailed to 136 schools in Kyonggi-do. A total of 106 questionnaires were usable, resulting in a 77.9% response rate. Teacher's teaching of good food habits and students satisfaction with school foodservices were surveyed in three schools from each system. Moreover, plate waste was measured to express cost and benefit in currency. Data were analyzed using the SAS package for description analysis, t-test, $\chi$$^2$ test, ANOVA, and the Vilcoxon rank sum test. Approximately seventy percent of 294schools in Kyonggi-do were operating commissary systems and most of them were of the rural (reduced paid) type. The number of meals served varied significantly between types of foodservice. The results of this study indicated that average food , labor utility , and supply costs were saved in the commissary system and that the total meal cost/person for a day was 1218.7 won compared to 1452.4 won in the conventional system. Though total meal costs were saved in the commissary system, dietitians had difficulties cooperating with school foodservice committees and supporters associations, especially in satellites of the commissary system. In addition, dietitians and teachers in the commissary system did not carry out teaching activities on good food habits to students as often as in the conventional system. Other problems that dietitians recognized in the commissary system were difficulties in training employees and parents for portion control and serving relatively simple menus. Students, as customers of school foodservices, are very important for system evaluation . Students in the commissary system scored of food itself , cleanliness of tableware, waiting time, quantity of meal and food temperature significantly lower than students in the conventional system. Moreover , the rate of plate waste was 20.5% in the commissary system as compared to 3.3% in the conventional system. Cost-effectiveness (saving 233.7won/person/day) is the main benefit of the commissary system. However , because of lower satisfaction scores and a highest plate waste rate, 201.9won/ person were wasted in the commissary system. The results of this study suggest that increasing the number of meals served within a commissary system might maximize the efficiency of the system, but increasing the number of satellites is not recommended because it might be out of dietitians control in many aspects.

• Korean Journal of Construction Engineering and Management
• /
• v.19 no.6
• /
• pp.124-134
• /
• 2018

Despite the many advantages of modular housing, low preference for modular housing for consumers who are familiar with RC structure leads to high construction cost of modular housing. The cost of modular buildings is about 130% of that of RC structures, so it is urgent to secure economical efficiency of modular buildings. Therefore, in this study, after calculating the savings amount of modular housing by type of construction work, economic analysis was conducted from a long - term perspective. In order to carry out the research, the authors compiled and analyzed the material cost, labor cost, and expenses incurred by each type of work by reclassifying the statement of the modular housing into the factory production and the site installation. After that, Pareto diagrams were created to find a core work that is included in the cost ratio of about 80%, and selected it as a cost reduction subject. Based on the assumption that the market size of domestic modular housing is similar to the level of modular advanced countries such as Japan and European countries, six cost reduction methods were set up that reflects the characteristics of the modular construction method and used for the expert interviews. Cost saving potentials in percentage from the interview were converted to the amount of savings that can be achieved by each type of method when applying the method. Finally, the findings of the study are expected to suggest long-term directions for technical development for modular construction and cost savings.

• Korean Journal of Soil Science and Fertilizer
• /
• v.24 no.1
• /
• pp.55-60
• /
• 1991

This study was carried out to obtain the effects of soil environment and characteristics on the growth and yield of young rice seedling. Twenty four rice fields were selected among the labor saving mechanization complex, and the growth statu s and various soil characteristics were investigated The young rice seedling planted soils were located at the range of elevation 5m to 210m, and the average water holding days was 5.1 days, and drainage class were mainly moderately well to imperfectly. The plant height on 30th day after machine transplanting were higher and the tiller numbers were smaller at the higher clay contents at moderately well and imperfectly drained soils. In case of sandy loam soils, the better the drainage class, the higher plant and more tillers. Soil hardness was lower in sandy loam, and the bulk densities of loam, silty clay loam and poorly drained soils were lower than the other fields. There were not differences of soil chemical properties between the soil textural groups but organic matter content were higher in poorly drained soils. The rice yields of young seedling planted fields were negatively correlated to soil bulk density and highly significantly correlated to the exchangeable calcium contents of the soils. The average yield of young rice seedlings was 487kg/10a, 2.5% higher than semi-adult rice seedling of 475kg/10a.

• Korean Journal of Construction Engineering and Management
• /
• v.6 no.4 s.26
• /
• pp.142-151
• /
• 2005

Several advanced countries have been continually developed PHC pile cutting automation machines for improving productivity, safety and quality of the conventional PHC pile cutting work. However, the target work of the previously developed PHC pile cutting automation machines is only crushing the head of PHC pile. Dangerous grinding work is still performed by workers with seven inch hand grinder. In domestic construction industry, the PHC pile cutting work is usually performed by a crusher and three to four skilled workers. Recent analysis results of the PHC pile cutting work reveal that it frequently makes a lot of cracks which significantly reduce the strength of the pile and is labor-intensive work. The primary objective of this study is to propose the end-effector which can effectively break PHC pile without any longitudinal cracks and to develop an automated pile cutting machine having unified grinder and crusher parts through a wide variety of laboratory and field tests. It is anticipated that the development of the automated pile cutting machine would be able to bring improvements in safety, productivity, quality as well as cost saving.

• Korean journal of applied entomology
• /
• v.17 no.2 s.35
• /
• pp.115-123
• /
• 1978

Present status on the pesticides production, supply, manufacture and pests control in Korea are summarized. The data in the past several years (1971-76) are analyzed to find out the problems and solutions for the further development of plant protection and pesticide industry in Korea. Since the acreages of crop plantation and the quantities of pesticides uses are already near to the stage of plateau, pesticide formulation with imported technical grade should be modified by local synthesis with imported quality. The government pesticides management act and regulations must be modernized urgently in connection with the synthesis. formulation, tests, registration, quality control. price and supply system as well as the safety use of pesticides. Recommendation concerning acceptable daily intakes(ADI) and residue limits must be established for the strengthning pesticide safety use and plant protection activities as soon as possible. The use of fungicide-insectide mixture in dust formulation must be authorized and practiced immediately for the labor saving and one-hit cooperative mass control of rice disease and insect pests, especially. At present, serious considerations on pesticide safety use and integrated pest control are strongly urged to help the farmers, to save the industries and to keep the nature as it is required.

• Journal of Bio-Environment Control
• /
• v.23 no.1
• /
• pp.26-30
• /
• 2014

Purpose of this study was a development of a sprayer arm auto control system that could be operated according to distance from pear trees for automation of pest control. Auto control system included two parts, hardware and software. First, controller was made with an MCU and relay switches. Two types of ultra-sonic sensors were installed to measure distance from pear trees: one on/off type that detect up to 3 m, and the other continuous type providing 0~5 V output corresponding to distance of 0~3 m. Second, an auto control algorithm was developed to control. Each spraying arm was controlled according to the sensor-based distance from the pear trees. And it could dodge obstacles to protect itself. Max and min signal values were eliminated, when five sensor signals was collected, and then signals were averaged to reduce sensor's noises. According to results of field experiment, auto control test result was better than non auto control test result. Spraying rates were 69.25% (left line) and 98.09% (right line) under non auto control mode, because pear trees were not planted uniformly. But, auto control test's results were 92.66% (left line) and 94.64% (right line). Spraying rate was increased by maintaining distance from tree.

• Korean journal of applied entomology
• /
• v.53 no.4
• /
• pp.479-483
• /
• 2014

The area of greenhouse horticulture has increased dramatically since the early 1990s in Korea. However, area per farmer still very small and diverse pest species occurs in greenhouse abundantly because of its protected condition. To manage pests, farmers use many pesticides frequently. Incessant and improper use of chemicals provoked pesticide resistance in pest and poisoning of farmers. In this study, we investigated the efficiencies of automatic dry fog sprayer for controlling two aphid species, Aphis gossypii and Myzus persicae, in greenhouse horticulture. When doors and side windows were completely closed in automatic dry fog sprayer treatment greenhouse, aphids were controlled similar level with conventional spraying method (percent control: 61.0~94.1%). However, when half of the doors and side windows of the greenhouse were opened, aphids were controlled poorly (percent control: 36.0~54.4%).

• Korean Journal of Plant Resources
• /
• v.18 no.3
• /
• pp.424-432
• /
• 2005

Newly introduced two lines of apios (Apios americana Medikus, red-vine and green-vine) were grown in Jeju island, to clarify their growth and production characteristics as well as to develope as a new edible crops in Korea. Both lines bloomed but did not develop to pod and seed. The red-viny line showed the habit of more early growth and maturity compared with green-viny line. Fresh tuber yields per 10a harvested in late November ranged from about 500kg to 800kg as according to the lines and cultural condition. Fresh tuber yield of red-viny line was relatively greater than that of green-viny line, mainly due to their higher tuber number per plant. Among the planting dates(April 1, April 16 and May 1) of seed tubes, highest tuber yield was obtained on May 16 planting. And the stacking cultivation culture was better than non-stacking cultivation in respect of tuber yield and disease avoidance. These results indicate that apios can produce in Jeju island, and in order to extend its cultivation to farmers it will be needed to develope some cultivars with high yields as well as labor-saving cultivation methods.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.186-186
• /
• 2017

Relay intercropping system of direct seeded rice and winter cereal is labor saving cultivation and has high land use efficiency in Japan. In this system, rice seeds are direct seeded into inter-row space of winter cereals (wheat or barley) in March or April. If the direct seeding of rice is conducted before stem elongation phase or using suitable seeder, these are little effect to yield of winter cereals. Though the seeds are generally thiuram treated, it's a matter that seedling establishment rate (SER) of direct seeded rice is low and unstable. The cause of low SER has not been revealed. In present study, with the aim to reveal causes of low SER, we conducted experiments and investigated the SER, and analyzed some factors that might affect SER. Experiment1: In 2015, 2016, we buried rice seeds underground, and investigated the transition of the seed survival rates (SSR). Seeds were thiuram-treated or non-treated. In 2 periods, SSR of thiuram-treated seeds were significantly higher than non-treated seeds. In 2016, thiuram-treated seeds were high in SSR (almost 75%) at April 30th, but low SER (10~27%) after harvest of winter cereals. Therefore, almost all of seed death might have been happen after germination. Analysis 1: We investigated the SER and cultivation conditions in Ibaraki pref. for several years. Meteorological factors were referred from the nearest point of AMeDAS. From mean temperature (MT) among 5days after and before the day, we divided the period of seeding ~June 20 to phase1~4. We defined each phase as below; Phase1: $MT{\leq}10^{\circ}C$, Phase2: $10^{\circ}C<MT{\leq}15^{\circ}C$, Phase3:$15^{\circ}C<MT{\leq}20^{\circ}C$, Phase4: $MT>20^{\circ}C$. We analyzed the correlation of SER and meteorological factors by each phase. Total number of days in phase 1~4 was significantly negative correlated with SER. In phase1, total rain fall and number of soil wetting days were significantly negative correlated with SER. In phase2~4, only MT was significantly positive correlated with SER. This result suggested that rainfalls in phase1 declined seed vigor to emergence from soil surface, by repeated water absorption and re-dry. From these present studies, it was suggested that one of factors of low SER of direct seeded rice in relay intercropping system is changing of water condition by rainfalls in phase1 ($MT{\leq}10^{\circ}C$). To improve SER, it's necessary to consider something seed treatments such as prevent water absorption during phase1. However, 58~60% of seeds seemed to die during May. It's suggested that, if seeds are thiuram treated, almost all of seeds can germinate underground, but the seed vigor to emergence from soil surface are insufficient. Further studies are needed to reveal the rest causes that is happening during emergence from soil surface.

• Korean Journal of Weed Science
• /
• v.30 no.4
• /
• pp.445-453
• /
• 2010

This study was conducted to investigate herbicidal efficacy and diffusibility of halosulfuron-methyl+mefenacet in water treated with 500 g great granule (GG) and 3 kg granule (GR). The 500 g GG was been spreading on the surface of the water within 6 minutes, 53 seconds, and it's active ingredient was diffused in the water bath of $10m^2$ size between 30 and 60 minutes. In addition, the diffusion of 500 g GG was influenced by moisture contents, so it have to immediately use 500 g GG in paddy fields when it was been unpacked. The herbicidal efficacy of the 500 g GG and 3 kg GR of halosulfuron-methyl+mefenacet was excellent to most weed species, but showed different efficacy for the control of Aneilema keisak and Scirpus juncoides, that was may be distribution pattern of active ingredient as different formulation.