• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.489-496
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• 2016

Recently, a concern about hollow core precast concrete (PC) slab has been increased as a method to improve the construction ability by reducing the self weight of structures during the construction. Hollow core slab which is known as a typical PC slab in domestic construction of PC building has a problem to put shear reinforcements in the web of element during the production of element in the factory. With regard to this point, recently, tripple ribs slab (TRS) which can be said as a new type of half PC slab system was developed. In TRS, it is possible to place shear reinforcements in PC element during the production of the element in the factory. This paper presents the shear test result of TRS which was done by one point loading test under simple support condition. Test parameters are the presence of cast-in-place (CIP) concrete and the contribution of lattice bars. From the test, it was found that the TRS has sufficient shear capacity to resist the design load and its strength can be predicted by the code equations for general beam. It is recommended to ignore the strength of lattice bar in the calculation of shear strength during the construction since its contribution is too low to be considered when CIP is not casted.

• Korean journal of applied entomology
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• v.31 no.3
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• pp.205-240
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• 1992

In reality, it is a green revolution of the entire agricultural matrix in Korea that integrated pest control plays an important role in the possible breakthrough in rice self-sufficiency. In paddy agroecosystem as man-modified environment, rice is newly established every year by transplantation under diverse water regimes which affect a microclimate. Standing water benefits rice by regulating the microclimate, but it favors the multiplication of certain pets through the amelioration of the microclimate. Further, the introduction of high yielding varieties with the changing of cultural practices results in changing occurrence pattern of certain pests. In general, japonica type varieties lack genes resistant to most of the important pests and insect-borne virus diseases, whereas indica type possesses more genes conferring varietal resistance. Thus, this differences among indica type, form the background of different approaches to pest management. The changes in rice cultivation such as double cropping, growing high-yielding varieties requiring heavy fertilization, earlier transplanting, intensvie-spacing transplanting, and intensive pesticide use as a consequence of the adoption of improves rice production technology, have intensified the pest problems rather than reduced them. The cultivation of resistant varieties are highly effective to the pest, their long term stability is threathened because of the development of new biotypes which can detroy these varieties. So far, three biotypes of N. lugens are reported in Korea. Since each resistant variety is expected to maintain several years the sequential release of another new variety with a different gene at intervals is practised as a gene rotation program. Another approach, breeding multilines that have more than two genes for resistance in a variety are successfully demonstrated. The average annual rice losses during the last 15 years of 1977-’91 are 9.3% due to insect pests without chemical control undertaken, wehreas there is a average 2.4% despite farmers’insecticide application at the same period. In other words, the average annual losses are prvented by 6.9% when chemical control is properly employed. However, the continuous use of a same group of insecticides is followed by the development of pest resistance. Resistant development of C. suppressalis, L. striatellus and N. cincticeps is observed to organophosphorous insecticides by the mid-1960s, and to carbamates by the early 1970s in various parts of the country. Thus, it is apparent that a scheduled chemical control for rice production systems becomes uneconomical and that a reduction in energy input without impairing the rice yield, is necessarily improved through the implementation of integrated pest management systems. Nationwide pest forecasting system conducted by the government organization is a unique network of investigation for purpose of making pest control timely in terms of economic thresholds. A wise plant protection is expected to establish pest management systems in appropriate integration of resistant varieties, biological agents, cultural practices and other measures in harmony with minimizing use of chemical applications as a last weapon relying on economic thresholds.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.783-795
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• 2009

We analyze the demand and supply in contents for platform differentiation in this paper. The contents provided by new platforms such DMB, IPTV which are introduced by the digital techniques and broadband network are almost same, so it is definitely necessary to differentiate the broadcasting contents for the development of telecommunication industry. To forecast the contents demand needed for each media, we assume 3 scenarios such as maximum, medium and minimum demand for contents considering deregulation of media policy. Also, we include the expected number of channels according to the changeover of policies as a variable for scenario. To predict the supply of contents of each media, we analyze 3 scenarios according to operating rates of production facilities as 100%, 70%, 50% and first-run ratio/rerun ratio of both terrestrial broadcastings and major program providers. The result shows that in case of scenario A, new contents for 453,484 hours are required every year and maximum contents that can be produced in present production facilities are just for 72,852 hours even in condition of 100% operating rate. This means that the unbalance of demand and supply of contents is extremely big and implies that the policies of focusing only on the development of platform and network industry are inadequate. It is time to foster contents business for differentiation of multiplatforms.

• Applied Chemistry for Engineering
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• v.19 no.6
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• pp.592-599
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• 2008

Oil sands had not received enough attention due to high production cost. However, as oil price significantly increases, oil sands are receiving more and more interest as unconventional crude oil. The value and applicability of oil sands can be enhanced by upgrading oil sands bitumen to produce synthetic crude oil (SCO). This study analyzed 213 oil sands upgrading patents applied between 1969 and 2006 in US, Canada, Japan, Europe, and Korea. The upgrading technologies could be classified into 9 detailed technologies; hydrocracking, coking, thermal cracking, deasphalting, supercritical technology, bio-technology, hydrotreating, gasification, and others. The number of patents applied for oil sands upgrading increased after 1970, reached a maximum in the early 1980, and slowly increases again in recent years. Korea has a lack of technologies for oil sands. Therefore, the technologies for oil sands production and application, specially, upgrading technologies based on accumulated oil refinery technologies need to be developed to increase self-development ratio of energy resource.

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.117-124
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• 2017

Objective: The purpose of this study was to examine the effect of changes in degrees of freedom of the fingers (i.e., the number of the fingers involved in tasks) on the task performance during force production and releasing task. Method: Eight right-handed young men (age: $29.63{\pm}3.02yr$, height: $1.73{\pm}0.04m$, weight: $70.25{\pm}9.05kg$) participated in this study. The subjects were required to press the transducers with three combinations of fingers, including the index-middle (IM), index-middle-ring (IMR), and index-middle-ring-little (IMRL). During the trials, they were instructed to maintain a steady-state level of both normal and tangential forces within the first 5 sec. After the first 5 sec, the subjects were instructed to release the fingers on the transducers as quickly as possible at a self-selected manner within the next 5 sec, resulting in zero force at the end. Customized MATLAB codes (MathWorks Inc., Natick, MA, USA) were written for data analysis. The following variables were quantified: 1) finger force sharing pattern, 2) root mean square error (RMSE) of force to the target force in three axes at the aiming phase, 3) the time duration of the release phase (release time), and 4) the accuracy and precision indexes of the virtual firing position. Results: The RMSE was decreased with the number of fingers increased in both normal and tangential forces at the steady-state phase. The precision index was smaller (more precise) in the IMR condition than in the IM condition, while no significant difference in the accuracy index was observed between the conditions. In addition, no significant difference in release time was found between the conditions. Conclusion: The study provides evidence that the increased number of fingers resulted in better error compensation at the aiming phase and performed a more constant shooting (i.e., smaller precision index). However, the increased number of fingers did not affect the release time, which may influence the consistency of terminal performance. Thus, the number of fingers led to positive results for the current task.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.488-494
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• 2015

This study aims to develop and apply a standard management self-diagnostic table for forestry households to better manage their astringent persimmon production. The diagnostic table consisted of 3 categories (general status of a forestry household, management performance indicators, level of management) and 18 subcategories. The current management status across 241 households was surveyed among 10 chief astringent persimmon producing municipalities. Scores from the 18 subcategories were aggregated for a total score to evaluate and compare different levels of management. The respondents scored an overall average of 57.4, 62% of which were placed between 40 and 60. Upon close examination Chungcheongnam-do scored a very low score in the 'management system-tree height' subcategory with respect to the average score potentially because of the large population of aged trees in the region. The national average in the 'production skills-time of fruit load adjustment' subcategory was only 1.96 because unlike sweet persimmons astringent persimmons adjust their own load by inducing physiological fruit drop. The national average in the 'management/sales skills-material purchase' subcategory was 2.01; over 60% of the respondents indicated a preference for independent selection and purchase for most materials. The households preferring a group purchase tended to utilize the regional co-op.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2002.11a
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• pp.5-6
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• 2002

In a comprehensive summary use and supplementation of some well defined natural herbal formulations in the European swine breeding and fattening is documented. Along with this data also the quality assurance, hygenic as well as the standards of efficacy of the formulations are presented. Series of experimental and development work over the last several years with universities, research institutes, veterinarians and feed industry proved that the application of such phylo-components (feed supplementation) result in to optimizing swine breeding practices. On the basis of 4 specific formulations tested and used in the European veterinary field most of the common problems of pig breeding and rearing can be successfully handled. Precisely, problems of fertility, respiration, diarrhea and stress; which are directly related to imerse losses in production, with poor quality of piglets associated with immune suppressions. Besides curing common symptoms, one of the most important aspect is of improvement in the self defence mechanism which results ultimately in to increased immunity, vitality and health of the animals; of course, thereby reducing the mortality which is the most economical problem observed in the animal health. Moreover, data presented here reflects on the fact that the use of such high quality alternative formulations successfully replace conventionally used antibiotics or hormonal therapies. They also work synergestically of as complementary in vaccination program or act as growth promoting agents on natural basis.

• Reproductive and Developmental Biology
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• v.33 no.4
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• pp.257-262
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• 2009

This study was to investigate pregnancy rate of IVM/IVF/IVC Korean cattle (registered in government) embryos according to transport time course. For the production of embryos, oocytes recovered from slaughtered excellent grade cow and highly motile frozen-thawed bull semen (purchased from LIMC, KPN#497) was used. In vitro produced embryos were cultured in CR1aa medium for 8 days and some of them were frozen. The rate of average cleavage (>2-cell) was 83.0% (308/371) and blastocyst rate at day 8 was 34.7% (107/308). Among in vitro produced blastocyst embryos at day 8, most healthy embryos were freshly transferred on production day and some frozen embryos were direct transferred on appropriate day. These embryos were produced in a laboratory, embryo transfer (ET) was planned in 10 areas of the remote island (Jeju) from the laboratory by airplane. Thus, we examined the pregnancy rate in recipient cow according to embryo of transport time course before ET. From embryo transferred 44 recipient cows, overall pregnancy was 40.9% (18/44), these 18 cows were all calved [single, 94% (17/18); twin, 6% (1/18)] and total embryo implantation rate was 26% (19/66). Comparing transport time in the base of 6 hr, pregnancy rate in ET group required less 4 hr (60%, 9/15) was significantly higher than that required more 6 hr (26.3%, 5/19). In direct ET of freezing embryos, the pregnancy rate was 40% (4/10). However, it was difficult to find the meaning of temperature, pH and corpus luteum quality of recipients on comparison of pregnancy rate. When the cell death level of embryos according to storage time in thermos (straw container) before ET was measured by TUNEL staining, apoptotic index was increased with storage time-dependent. These results demonstrated that long distance transfer of IVM/IVF/IVC embryos is possible and the time of embryo transport is very important for the pregnancy rate on field trial.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.232-238
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• 2010

Maize double cropping with winter cereals is important for round-year production of forage or grain, and increase of self-sufficiency of upland grain crops such as maize and wheat. Changes of maize growth and yield for forage or grain according to late planting in June for double cropping with winter barely were investigated compared to proper planting in April for three years from 2007 to 2009. Forage and grain yields of maize planted in mid or late June decreased by 20~30% compared to proper planting in April, but total grain yields per year of double cropping increased by 30~40% compared to single cropped maize. Reduction of ear dry matter was less than that of stalk in late planting within maize plant part. Yield reduction by late planting was the least at Kwangpyeongok, which showed the highest grain yield, 850 kg $10a^{-1}$ in even though late planting in June. Meteorological condition during harvesting time of double cropped maize, which in late September (forage) and mid October (grain), were better than that of conventional maize harvesting time which in late August and mid September. It is thought that more researches for double cropped maize for higher grain production is needed in the future.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.172-181
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• 2012

The film industry is a high value-added industry, boosts the self-esteem of the people as a measure of a country's culture industry, and is one of the strategic industries to be fostered. However, the film industry is struggling due to the lack of national consensus on the importance and value of the film industry. Therefore, in order to resolve this issue, the study used the film Input-Output Table of year 2009 of korea to analyze how much the film industry contributes to the national economy. The results shows that film industry induce 82,838.7 billion won of national production, especially the film industry(the sector of film product & distribution and film screenings) shows that production inducement coefficient is 2.324(2.240, 2.478), Index of the power of dispersion is 1.163(1.121, 1.240), index of the sensitivity of dispersion is 0.825(0.825, 0.501), value-added coefficient is 0.884(0.479, 0.547), income inducement coefficient is 0.454(0.211, 0.236), tax inducement coefficient is 0.110(0.090, 0.146) and employment inducement coefficient is 0.017(0.014, 0.022).