• Korean Journal of Construction Engineering and Management
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• v.10 no.6
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• pp.58-66
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• 2009

Due to a shortage of professional labor and the stagnant construction industry in recent days, there has been an increasing demand for securing profitability through cost reduction. Though its importance in the cost and its great influence on the safety and durability of structures, the labor intensiveness of rebar work has caused a serious problem of rising cost accompanied by the loss of rebar materials. In the plant manufacturing process, rebar is cut and bent at the automated facilities and conveyed to the construction site, which makes it possible to manufacture higher-quality bars and to reduce the losses from rebar materials. Different from the expectation, however, this type of plant manufacturing still has not been active since its first introduction in 1990s. In this study, a research on the actual condition of rebar manufacturing plant has been implemented and a standardized rebar manufacturing has been provided as a way to activate rebar manufacturing.

• Journal of Life Science
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• v.13 no.4
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• pp.428-432
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• 2003

This study was carried out to develop and investigate integrated mechanization system for culture of carrot. Compared with the conventional hand planting, use of a mechanical planter for pelleted seeds resulted in a saving of planting time by 225 hours. An additional saving of 460 hours was obtained for thinning the seedlings. Besides seeds could be saved by 72%, planting and thinning be done only in 35 hours per ha field when the pelleted seeds were planted with a planter. Work hour reduced by adopting the mechanical planting of pelleted seeds sharply contrasted to that of 720 hours required for hand-planting the thinning hours, resulting in a reduction of labor by more than 95%. SMP followed pelleting tended not only to increase the percentage of seedling emergence in the field but to induce an a day earlier germination.

• Korean Journal of Plant Resources
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• v.13 no.3
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• pp.208-212
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• 2000

The effect of heat covering materials during cultivation of Shigyoku grape was examined on the effect of protection from freezing damage, labor reduction, and disease resistance during the wintering. This experimentwas accomplished using different combination of heat covering materials from the end of Nov as follows: straw and heat conservation cover B, kilding, color fabric A, and white needle punching fabric. Capacity of heat conservation was the least form white needle punching fabric, and the differences of other materials was slight. Early sprouting occurred by the treatment with heat conservation cover B, and the rate of sprouting was about 70.7% after 9 days of sprouting, showing 2.3-12.5% increase. Growth effect was not differ between heat conservation materials. Disease and insects occurred by the in dice 3.0-3.2 of crown gall from the heat conservation cover B treatment. Other damages were not observed or very little from other treatments. Demand of labor during steps of these treatments was more observed by 6% for kilding than heat conservation cover B, and those of color fabric A and white needle punching fabric were reduced by 6 and 15%, respectively.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.409-420
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• 2021

The safety and health ledger system, which gives the responsibility of safety and health management for construction site workers to the construction project owner, was introduced as part of the overall revision of the Occupational Safety and Health Act. There is a need to explain the system's effectiveness in terms of economic feasibility to solve the execution problem of the system caused by low awareness and implementation rate. In this study, the economic effect of implementing the safety and health ledger system was analyzed using cost-benefit analysis based on the data discussed at the time of the introduction of the system. Results show that creating and managing the design safety and health ledger caused additional costs in implementing the system. As a result of comparing the cost of preparation and the direct and indirect benefits caused by the reduction of industrial accidents, the benefits were evaluated higher than the costs. Thus, it is thought that the safety and health ledger system reduces construction work accidents and generates economic effects.

• Journal of Climate Change Research
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• v.9 no.4
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• pp.377-384
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• 2018

The chamber method is widely used for measuring methane emission from paddy rice fields. The closed static chamber has advantages of easy installation and removal in the field and low manufacturing cost. However, the manual chamber method requires a lot of labor and has a limited sampling time and frequency. To overcome the disadvantages of the manual chamber, the auto-chamber system is used for measuring methane emission. We compared the differences in methane flux between the auto-chamber and manual chamber. To investigate methane emissions by the two methods, a chamber was installed for each of the following treatments : control without rice straw (NA), spring plowing after autumn rice straw application (SPRA) and autumn plowing after autumn rice straw application (APRA). The total methane emission was lowest in the control and highest in APRA with both methods. There was no significant difference in total methane emission between the methods, but dynamic fluctuation in methane with temperature change was accurately measured in the auto-chamber. Measuring methane emission with an auto-chamber system is expected to reduce uncertainty and increase accuracy, accompanied by labor reduction.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.85-96
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• 2022

The study is aimed to investigate the features and socio-economic background of farmland consolidation project with medium-sized paddy plot at irrigation associations during the Japanese colonial period in Korea. Most of farmland consolidation works in the 1940s was composed of independent irrigation and drainage ditches along the short side of field plot. However, the number of farm roads at farmland consolidation zone was much smaller than number of irrigation ditches to decrease reduction in farmland area. The standard field plot was medium-sized (about 20-40 ares) in Korea but small-sized (about 10 ares) in Japan in this period. As the result of farmland consolidation works, the unit water requirement was increased to 0.0035 m³/s/ha, and the unit area drainage discharge was over 2.0 m³/s/km² in many cases. The farmland consolidation with medium-sized plot have been spread under the colonial landlord system, where major landlords occupied a large share of farmland and managed corporate farming to gain more benefit. The reasons for spread of farmland consolidation with medium-sized plot may be as follows: high net profit ratio, an increase in land price, and labor savings in rice farming. The farmland consolidation with medium-sized plot in the colonial period showed intermediate features between the farm consolidation with small-sized plot for an increase in land productivity in Japan and the farm consolidation with medium-sized plot for an increase in labor productivity after the 1960s.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.347-353
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• 2023

Measuring the growth of fish in fish farms still uses a laborious method. This method requires a lot of labor and causes stress to the fish, which has a negative impact on mortality. To solve this problem, we propose the Fish Growth Regression System (FGRS), a system to automate the growth of fish. FGRS consists of two modules. The first is a module that detects fish based on Yolo v8, and the second consists of a module that predicts the growth of fish using fish image data and a CNN-based neural network model. As a result of the simulation, the average prediction error before learning was 134.2 days, but after learning, the average error decreased to 39.8 days. It is expected that the system proposed in this paper can be used to predict the growing date and use the growth prediction of fish to contribute to automation in fish farms, resulting in a significant reduction in labor and cost savings.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.187-208
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• 2000

By the activation of ovary hormone, many morphological changes occur in the epithelial cell lines and muscle cells in rat uterus. These two cells in uterus are important to the implantation of embryo, maintaining pregnancy and starting parturition. One important change associated with the morphological change of these two cells in uterus is the change on prostaglandin(PG) metabolism. Its presence and synthesis in endometriurn and myometrium in uterus affects estrous cycle and the start of embryo implantation in uterus. It also performs as an important modulator in parturition. So the abnormally weak expression of PG causes difficulty during labor and over-expression causes pre-term labor. PG biosynthesis starts from either free or liberated arachidonic acids from membrane phospholipid by phospholipase. Such arachidonic acids are converted into PG catalyzed by Cyclooxygenase. Under normal physiological condition, Cyclooxygenase-1(COX-1) having 602 units of amino acids controls the synthesis of PG. It acts as a local hormone regulating vasomodulation of blood flow, flexible muscle movement, increasing the blood permeability and contributing the protective role in preserving integrity of the stomach lining and Cyclooxygenase-2 (COX-2) is induced by the inflammation, pregnancy and increased its expression until parturition. Lipid metabolite like PG is located in uterine and expression of COX-2 increased with pregnancy. Increased expression of COX proteins in epithelial cells and myometrial cells are told to increase the muscle contractility in uterus but decreased right after the labor in rat. It is a good sign indicating that COX proteins are deeply related to the start of labor. Currently, Several studies report the use of PG and COX-2 inhibitor as medication for controlled abortion or to prevent pre-term labor but they entail various side-effects. Our study proposed to suggest use of acupuncture as an another mediator to control abortion or pre-term labor without causing unnecessary side-effects by those medicines. Two acupuncture sites, LI-4 & SP-6 were selected due to their known efficacy. From the immunohistochemical staining of COX-2, normal expression of COX-2 protein in nonpregnant SD rat's uterus revealed that COX-2 protein was primarily detected in the lumina epithelial lining and in the epithelial cell lining contacting the stromal cells. High resolution optical microscopic scanning revealed distinguishable staining in the myometrial mucosa. LI-4 acupuncture administered nonpregnant rat's uterus showed strong expression for COX-2 in endometrium contacted with lumina epithelial lining of rat uterus and in myometrial mucosa. Stromal cells showed more staining than untreated nonpregnant rat's uterus and stronger staining in stromal cells contacting myometrial layer compared to untreated nonpregnant rat's uterus. SP-6 acupuncture administered nonpregnant rat's uterus showed weak expression for COX-2 in myometrial layers and stromal cells but no staining was visible in lumina epitheliai and glandular epithelial cells. Few stromal cells and myometrial mucosa were positively stained for COX-2. Pregnant SD rat's uterus was also immunostained for COX-2 expression after 18 days of pregnancy. Unlike to untreated nonpregnant rat's uterus, luminal epithelial cells were not positively stained for COX-2 but stronger staining for COX-2 was revealed in stromal cells. LI-4 acupunctured SD rat's uterus had very strong expression of COX-2 in luminal epithelial lining. Few stromal cells showed stronger positive COX-2 staining and myometrial layers also showed more expression than untreated pregnant rat. SP-6 acupuncture administered pregnant SD rat's uterus showed positive expression of COX-2 in epithelial cells of luminal mucosa layer but weaker than that of LI-4 acupuncture treatment's case. However, strong positive staining was revealed in stromal mucosa and myometrial layers. Virgin SD rat's uterus motility index during LI-4 acupuncture was 66.52 % (Prob〉T = 0.0197) compared to its motility before the acupuncture treatment but the motility index was slighdy elevated up to 79.58 % (Prob〉T = 0.1175) after the acupuncture. During the SP-6 acupuncture treatment for 30 minutes, uterus motility index was 90.52 % (Prob〉T = 0.1832) showing lesser decrement but consequently reached similar motility index decreasal to 79.95 % (Prob〉T = 0.0215) after the acupuncture treatment as LI-4 showed. LI-4 acupuncture tend to be a quick treatment to reducing the uterus motility in a virgin rat but eventually both two acupuncture administration created very similar reduction of uterus motility seeing the index after the both acupunctures. The uterus movement monitored during the LI-4 acupuncture administered for 30 minutes, Pregnant SD rat showed decreased motility down to 77.90 % (Prob〉 T = 0.0076) compared to uterus motility before the acupuncture and it continuously decreased down to 71.81 %(Prob〉T = 0.0214) after the removal of needle. The statistical analysis using paired t-test showed significance difference for both two motility indexs at =0.05. SP-6 acupuncture administered to pregnant SD rat also had similar pattern of decreasing uterus motility index down to 74.70 % (Prob〉T = 0.1730) during the initial 30 minutes acupuncture administration and it was continuously lowered to 71.52 % (Prob〉T = 0.0155) after the acupuncture. The paired t-test resuit for SP-6 suggest prompt response of uterus motility index to the SP-6 acupuncture treatment but consequently reached same level of inducing the motility reduction as LI-4 at =0.05 level.

• Journal of Service Research and Studies
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• v.7 no.1
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• pp.65-82
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• 2017

This study is to examine the effects of high commitment HRM on service performance in the service industry, and to examine the mediating effect of the organizational internal innovation direction. Specifically, the direction of internal innovation consists of high-value-added HR and service and cost-reduction downsizing. We assumed that the high-value-added direction of HR and service will have a positive mediating effect. And assumed that cost-reduction downsizing direction has negative mediating effect. The data were collected from 2013 workplace panel survey(WPS) of the Korea Labor Institute(KLI). Among the 1,775 companies, 896 companies classified as wholesale and retail, transportation, professional scientific services, education services, health social services, financial services, and other services (such as information society support services) were extracted and used. In summary, high-commitment HRM has a positively significant effect on the direction of high value-added innovation of HR and services, and has a negatively significant effect on the cost-reduction downsizing direction. In addition, the direction of high value-added innovation of HR and service was positive effect on service performance, and cost-reduction downsizing innovation direction has a negative effect on service performance. And the direct effect of high commitment HRM on service performance has not been confirmed. However, we confirmed the positive mediating effect of high value-added innovation direction of HR and services, and confirmed that the negative mediating effect of cost-reduction downsizing. Therefore, it is confirmed that the two variables have a full mediating effect on the relationship between high commitment HRM and service performance.

• Journal of Labour Economics
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• v.24 no.3
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• pp.13-38
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• 2001

The question about whether a shorter workweek may increase employment has been a serious issue and been furiously debated among collective bargainers. The advocators recommend publicly that a reduction in standard working hours will provide benefits to the unemployed through the provision of new jobs, and also can improve the quality of life workers. The opponents argue that a shorter workweek will increase labor costs and induce firms to reduce their production levels, and consequently cut back their demand for labor. Although the debate is still continuing, considerable has been made toward achieving the goal workweek reduction. The analytical framework of this paper is a Putty-clay-model, in which the short-and long-term impacts of changes in working time on the employment associated with the interrelations of wages, prices, hourly labour productivity, the firm's labor demand, business cycle and economic growth etc. must be analyzed.