• Journal of Internet of Things and Convergence
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• v.8 no.2
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• pp.35-40
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• 2022

In the agricultural environment, pesticide control requires a high risk of work and a high labor force for farmers. The effectiveness of pesticide control using unmanned aerial vehicles varies according to climate, land type, and characteristics of unmanned aerial vehicles. Therefore, an effective method for pesticide control by unmanned aerial vehicles considering the spraying conditions and environmental conditions is required. In this paper, we propose an efficient pesticide control system based on agricultural unmanned aerial vehicles considering the application conditions and environmental information for each crop. The effectiveness of the proposed model was demonstrated by measuring the drop uniformity of pesticides according to the change in altitude and speed after attaching the sensory paper and measuring the penetration rate of the drug inside the canopy according to the change in crop growth conditions. Experiment result, the closer the height of the UAV is to the ground, the more evenly the crops are sprayed, but for safety reasons, 2m more is suitable, and on average a speed of 2m/s is most suitable for control. The proposed control system is expected to help develop intelligent services based on the use of various unmanned aerial vehicles in agricultural environments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.164-172
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• 1983

The present study was conducted to investigate the variations in morphological traits, yield and yield-related components of rice cultivars exposed to different weather conditions by growing at the locations with different altitude but with equal latitude. Three Japonica varieties (Daegoldo, Jinheung, Shin #2) and three Tongil type semi-dwarf varieties(Josaengtongil, Suweon 287, wx 817-65-2-3) were seeded at Suweon on April 21 and transplanted at Suweon ($127^{\circ}$ N37 20', altitude 37m) and Jechun ($128.2^{\circ}$, N37 10', altitude 280-300m) on June 1 with the spacing of 30 $\times$ 15 em. The morphological traits, yield and yield-related components were measured. Culm length, paincle length and 1000-grain weight showed a little increase in Japonica varieties in Jechun as compared to those in Suweon and vice versa in semi-dwarf varieties, showing no significant differences. Number of panicles, per hill and number of spikelets per panicle among yield-related components showed remarkable increase in all varieties in Jechun as compared to those in 'Suweon but such inter-locational differences differed with varieties within varietal group and between varietal groups. On the contrary, grain fertility was higher in Suweon than that in Jechun and in Japonica varieties than that in semi-dwarf varieites , showing greater inter-locational difference in semi-dwarf varieties. Among Japonica varieties Jinheung and Shin #2 showed remarkable increase in yield in Jechun as compared to that in Suweon but in semidwarf varieties it was just the opposite. The importance of each of the yield-related component contributing to yield showed similar tendency 'regardless of locations in Japonica varieties. However, it was evidently different between locations in semidwarf varieties, where number of spikelets per panicle showed greatest direct effect on yield in Suweon but in Jechun so did grain fertility followed by the number of spikelets per panicle.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.55-61
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• 2023

This study aims to develop CLSM fill material for emergency restoration using landfill coal ash. As a result of examining physical properties such as particle size distribution and fines content of landfill coal ash, bottom ash, fly ash, and general soil were mixed, and SP was found to have a density of 2.03 and a residual particle pass rate of 7.8 %. CLSM materials that secure fluidity in unit quantities without using chemical admixtures such as glidants and water reducing agents have a high risk of material separation due to bleeding. As a result of this experiment, it was found that the bleeding ratio did not satisfy the standard in the case of the specimen with a large amount of fly ash and a lot of addition of mixing water. As a result of the compressive strength test, the strength development of 0.5 MPa or more for 4 hours was found to be satisfactory for the specimens using hemihydrate gypsum with a unit binder amount of 200 or more, and the remaining gypsum showed poor strength development. Although it is judged that landfill coal ash can be used as a CLSM material, it is necessary to identify and apply the physical and chemical characteristics of coal ash buried in the ash treatment plant of each power generation company.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.3
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• pp.13-26
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• 2024

This study investigates how entrepreneurial competencies affect firm outcomes for necessity entrepreneurship in Korea. Based on a survey collected from 162 necessity entrepreneurs, this study conducted multiple regression analysis. The statistical results show that founder entrepreneurial competencies, such as risk-taking, tend to be associated with positive outcomes financially as well as non-financially, which suggests that the existing propositions of previous research on the relationship between risk-taking and firm performance can be applied to necessity entrepreneurship as well. Additionally, founder opportunity competencies and resilience increase the likelihood of better financial performance in necessity entrepreneurship compared to others, whereas their effect on non-financial performance is not statistically significant. This indicates that necessity entrepreneurs are likely to focus more on financial performance to survive than on non-financial performance, particularly concerning variables related to sustainability such as the environment and society. The findings of this study contribute to knowledge concerning the role of necessity entrepreneurs' competencies in the performance of their companies.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.136-179
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• 1976

Effects of seeding pattern and rate on the yield and some agronomic characters of barley under different cultural conditions were observed at Suweon, Daejeon and Jinju during the barley growing season from 1972 to 1974. Plant height and culm length were increased by dense seeding, shading, heavy fertilization, moving location down to the lower latitude. The tiller number per plant, dry matter weight, leaf number on main stem, percentage of valid tillers, RGR, NAR, and $R_{A}$ were increased by heavy fertilization, sparse seeding, reduced furrow width and drilling likewise the length, width and angle of leaf. The newer cultivar had higher RGR and NAR. The higher yielding cultivars had higher potential for carbohydrate assimilating ability. Straw weight and grain yield were increased by dense seeding, reduced furrow width, drilling, heavier fertilization and moving the location to the south, and then decreased by shading and late seeding. High yield increase by drilling was found in late seeding. The optimum seeding rate for the yield increase were 15l/10a for furrow and 25l/10a for drilling. The spike number type cultivars were favourable for the sparse seeding and the spike weight type cultivars seemed to be suitable to the dense seeding, The repeatability of days to heading due to location and fertilizer level was higher than that of seeding time and seeding method. Repeatability of culm length was extremly high in seeding method and comparatively high in fertilizer level while low in location. The repeatability of yield due to location and seeding methods was comparatively high, but the tendency was different along with different cultivars. Also the repeatability of yield due to the fertilizer level was generally high except cultivar Haganemngi.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.241-245
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• 1983

PraziquantEI ($Distocide^{\circledR}$), the KcrEan product, was tEstEd for its safety and Efficacy in treatmEnt of Clonorchis sinensiJ infccticn during the period from April to SeptembEr, 1983 in Korea. A total of 55 egg positive cases were selected and treated with the regimen of 25 mg/kg t.i.d. for 1 day (total 75 mg/kg). The follow-up stool examination was done in 47 cases by cellophane thir;k smear and Stoll's egg counting techniques. The 8 uncured cases were treated again with the same regimen. The laboratory tests for blood picture and liver function were done in 27 cases and compared before and after the treatment. The results obtainEd are as follows: 1. After single course treatment, the cure and egg reduction rates were 83.0 and 99.1% respectively. With the second treatment, excellent results of 100% in both rates were obtained. 2. Several kinds of side effects such as dizziness, headache, etc. were complained by 29 cases (61.7 %), however, those were so mild and transient that no special treatment was necessary. 3. No significant change in laboratory findings was recognizable before and after the treatment. From the above results, it is concluded that $Distocide^{\circledR}$ is as effective and safe as $Biltricide^{\circledR}$ and highly recommendable in treatment of C. sinensis infection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.684-696
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• 1995

A mutant for chalky endosperm and genetic male sterility (GMS) was newly developed in rice. The two characters were found to be controlled by single recessive gene which has pleiotropic effect, indicating that chalky seeds should be GMS seeds in segregating populations. Chalky seeds showed the same shape and size as normal seeds. However, starch composition of central part of endosperm was looser and shape of starch granules was rounder compared with normal endosperm, resulting in significantly lower grain weight, absolute density and grain hardness in chalky grains than in normal ones. Amylose content and gel consistency of chalky grains were much lower and harder, respectively. Male sterile plants showed much shorter plant height, poorer panicle exsertion and lesser panicle number compared with normal plants. Microspore abortion stage in pollen developmental process was observed as before meiosis. Male sterility of the mutant was stable regadless of temperature and day length. A system breeding hybrid rice using this mutant was discussed, comp ring with other systems utilizing cytoplasmic-genic male sterility(CGMS) and environment sensitive GMS(EGMS). Separation of GMS seeds in mixed seed bulks by specific gravity (1.14∼1.16g / cm3) was successful about 85∼90%. But some mixed normal plants were seemed to be easily removed by the apparent difference in growth characters at seedling stage. The highest natural outcrossing rate of this GMS line was as 17.3 % in a plot treated with 2-row pollinator, I-row GMS, and GA3 + cutting of flag leaf + pollen-scattering by rope.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.449-457
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• 2005

This study was conducted to evaluate the effects of feeding rye silage on growth performance, blood and carcass characteristics in finishing pigs. The total of eighteen $(Landrace{\times}Yorkshire{\times}Duroc)$ pigs $(94.03\pm0.71kg)$ were used in a 28-days assay. Dietary treatments included 1) CON(commercial diet ME 3,350 kcal/kg and crude fiber $2.84\%$), 2) T1(ME 3,294kcal/kg and crude fiber $2.99\%$ diet with rye silage $1.66\%$) and 3) T2(ME 3,237kcal/kg and crude fiber $3.15\%$ with rye silage $3.32\%$). In growth performance, total feed intake, basal feed intake and average daily feed intake were significantly higher in T1 and T2 treatments than CON treatment(P<0.05). Cortisol concentration in blood of pigs fed rye silage was significantly decreased compare to pigs fed CON diet(p<0.05). In meat quality characteristics, the hunter's $L^*$ value and marbling of pork were the highest in T2 treatment among treatments (P<0.05). Fatty acid composition in lean meat, the composition of palmitic and arachidic acid were significantly Higher in CON than others(P<0.05), also, palmitoleic acid was highest in T2 treatment among treatments(P<0.05). In fats those, palmitic and arachidic acid were the highest in CON treatment than those of other treatments(P<0.05). Digestibility of dry matter and nitrogen in pigs fed T1 and T2 diets were greater than that of pigs fed CON diet(p<0.05). Propionic acid concentration of fecal was the highest in T1 treatment among treatments(P<0.05). In conclusion, feed intake, the hunter's $L^*$ value, meat color of sensory evaluation and marbling of pork were affected by $3.32\%$ rye silage feeding.

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.853-869
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• 2000

Background : Following several decades of decline, the incidence of tuberculosis has recent1y begun to increase in many countries of this the control of this disease has been impeded by the emergence of multi-drug resistant tuberculosis (MDR-TB). The development of rapid diagnostic methods and effective new drugs are needed to control MDR-TB. One of the new drugs for MDR-TB is rifabutin (RBU) which has been known to be effective in some patients with MDR-TB. A few reports showed that some types of mutations of the rpoB gene, which were known to be present in 96-98% of rifampicin-resistant M. tuberculosis, were associated with the rifampicin-resistant but RBU-susceptible phenotype. This study was performed to investigate the correlation between RBU susceptibility and the patterns of rpoB gene mutations in Korean MDR-TB. Methods : Sixty-five clinical isolates of multi-drug resistant Mycobacterium tuberculosis, gathered from patients who visited the Asan Medical Center from July 1997 to June 1999, were investigated. Clinical responses to rifabutin-containing regimen were evaluated. An RBU susceptibility test and sequencing analysis of rpoB gene were performed, and the results were analyzed to confirm which mutations correlated with RBU-susceptible MDR-TB. Results : Fifty-three of 56 (95%) clinical isolates of MDR-TB had 60 mutations of the rpoB gene. The most frequent mutations were found at codon 531 (43%), and two mutations were combined in seven clinical isolates. Five of 53 (10%) clinical isolates showed the RBU-susceptible phenotype, and in them the characteristic patterns of point mutations were found at codon 509, 516, and 526. Conclusion : The frequency and pattern of mutations of the rpoB gene of Korean MDR-TB isolates were similar to those in western countries, where the prevalence of tuberculosis is low, but some show RBU-susceptible phenotypes. RBU-susceptible MDR-TB isolates showed the characteristic pattern of mutations of the rpoB gene which could be used to rapidly diagnose RBU susceptibility.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.169-178
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• 2000

Background : Usually fever subsides within one week in over 90% of pulmonary tuberculosis (TBp) patients after the start of short-course anti-tuberculosis therapy, but occasionally it persists over two weeks after treatment. When the fever persists, drug resistance, combined infection, or drug fever, and so on, are considered as an etiology and, in some cases, drugs are changed. But inadvertent discontinuation of a short-course regimen inevitably will extend the duration of treatment, and the treatment completion may be delayed. This study was performed to investigate the causes of prolonged fever (PF) and to identify the predictors of PF in drug-susceptible TBp patients in Korea. Method : Five hundred-ninety-eight patients, who were admitted to Asan Medical Center from January 1996 to March 1999, diagnosed with TBp and prescribed short-course, anti-tuberculosis treatment, were reviewed. PF was defined as having fever over two weeks despite treatment. The causes of PF were analyzed. Drug-sus-ceptible TBp patients who presented no causes for PF, except turberculosis itself, were selected(n=22), and they were compared with those who had no fever at diagnosis (n=22) and those who had fever at diagnosis, which had subsided within two weeks after treatment (n=22). Clinical, laboratory, and radiological parameters were compared among the three groups. Results : Twenty-eight (4.8%) of 598 patients showed PF over two weeks despite short-course treatment. The causes of PF were drug fever (n=2), multi-drug resistant tuberculosis (n=3), disseminated Mycobacterium kansasii infection (n=1), and drug-susceptible tuberculosis itself (n=22). The patients with PF had more risk factors for tuberculosis, long duration of symptoms before treatment, night sweats, weight long, numerous acid fast bacilli on sputum smear, anemia, hyponatremia, hypoalbuminemia, over three lung cavity numbers and extensive infiltration, indicating that they had prolonged and extensive lung diseases. Conclusion : The main cause of PF in TBp despite short-course regimen seems to be drug-susceptible but extensive disease in Korea. Any changes to the drug regiment provided for TBp patients with prolonged fever despite treatment should be carefully considered.