• Journal of Sericultural and Entomological Science
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• v.15 no.2
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• pp.9-14
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• 1973

In order to find out effects of the generative power of silk worm moth which have been brought up in the high temperature accommodation at their pupa stage. For this specific study, 9 different kinds of male silk worms have been selected as specimen. All those specimen were brought up in the normal temperature at their larvae stage and after the pupation period they have been accommodated in the condition of high temperature for a certain length in accordance with the study programme. Afterwards, those mlae specimen were copulated with Suwon jam 103${\times}$104 which were all brought up in normal conditions. This study was carried out to find the copulation function as well as the ratio of unfertilized eggs(male sterility test). Results of study have been revealed as follows: 1) Although some differences were observed, male pura which have been brought up in the condition of high temperature shown the low rate of unfertilized eggs rather than those were brought up in the normal conpition. 2) In this group the eclosion(emergency) has been found to be poor rather, than those specimen brought up in normal conditions. 3) The copulation function of Moran, Daedong, J124 and C108 specimen were found to be poor than those of Suwon jam. 4) Fertility rate of Moran, Daedong, J124 and C108 was found to be around 65%. This figure is rather lower than what we normally expect. 5) Unfertilized egg ratio of Moran, Daedong and C108 were found to be around 20% if they were brought up in the condition of high temperature for one day from the time of pupation: 40% at 2 days, and 70% at 3 days duration. More than 3 days treatment has shown no progress in the unfertilized egg ratio. 6) One day's treatment for the pupa at the later stage has shown the unfertilized egg ratio of about 10%; 20% at 2 day's treatment, 35% at 3 day's treatment, 40-60% at 4 day's treatment, more than 60% at 5 day's treatment, and the 70% of fertilized egg ratio was only observed when the treatment days come to 7 days. It was understood that the unfertilized egg ratio was high at the antepupa stage rather than that of post-pupa stage. 7) According to the result of observation the sperm in copulatory pouch and seminal receptacle out of the normal female silk worm which have been copulated with the male brought up in the condition of high temperature at their moth stage. The reproduction system found in the control zone has been found to be normal and the sperm is amountful and active in motion while the sperm found in the treatment to be limited in amount and slow in motion. The observation was made within 5 hours from the copulation. 8) According to the result of observation of sperm of seminal receptacles of the female silkworm moth, and according to that observation of sperm in the seminal receptacle in female silkworm moth, the amount of sperm and mobility in the female moth brought up in high temperature were poor comparing that were brought up in normal temperature zone. Some of them are even found to be no trace of such. 9) Appearance and mosle of the copulatory organ of the male silkworm moth was found to be no anatomical change. 10) Testis of the later pupa stage which was brought up in the high temperature was found to be almost net developed to anucleate sperm and they are degenerated at stage of between maturation division and sperm abnormal stage. Mean time at control zone, the formation of anucleate sperm was already observed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.95-112
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• 2020

This paper is to investigate how cognitive bias of college students and entrepreneurs relates to perceived risks and entrepreneurial opportunities that represent uncertainty, and how various cognitive bias and entrepreneurial efficacy In the same way. The purpose of this study is to find improvement points of entrepreneurship education for college students and to suggest problems and improvement possibilities in the decision making process of current entrepreneurs. This empirical study is a necessary to improve the decision-making of individuals who want to start a business at the time when various attempts are made to activate the start-up business and increase the sustainability of the existing SME management. And understanding of the difference in opportunity evaluation, and suggests that it is necessary to provide good opportunities together with the upbringing of entrepreneurs. In order to achieve the purpose of the study, questionnaires were conducted for college students and entrepreneurs. A total of 363 questionnaire data were obtained and demonstrated through structural equation modeling. This study confirms that there is some relationship between perceived risk and cognitive bias. Overconfidence and control illusions among cognitive bias have a significant relationship between perceived risk and wealth. Especially, it is confirmed that control illusion of college students has a significant relationship with perceived risk. Second, cognitive bias demonstrated some significant relationship with opportunity evaluation. Although we did not find evidence that excess self-confidence is related to opportunity evaluation, we have verified that control illusions and current status bias are related to opportunity evaluation. Control illusions were significant in both college students and entrepreneurs. Third, perceived risk has a negative relationship with opportunity evaluation. All students, regardless of whether they are college students or entrepreneurs, judge opportunities positively if they perceive low risk. Fourth, it can be seen from the college students 'group that entrepreneurial efficacy has a moderating effect between perceived risk and opportunity evaluation, but no significant results were found in the entrepreneurs' group. Fifth, the college students and entrepreneurs have different cognitive bias, and they have proved that there is a different relationship between entrepreneurial opportunity evaluation and perceived risk. On the whole, there are various cognitive biases that are caused by time pressure or stress on college students and entrepreneurs who have to make judgments in uncertain opportunities, and in this respect, they can improve their judgment in the future. At the same time, university students can have a positive view of new opportunities based on high entrepreneurial efficacy, but if they fully understand the intrinsic risks of entrepreneurship through entrepreneurial education and fully understand the cognitive bias present in direct entrepreneurial experience, You will get a better opportunity assessment. This study has limitations in that it is based on the fact that university students and entrepreneurs are integrated, and that the survey respondents are selected by the limited random sampling method. It is necessary to conduct more systematic research based on more faithful data in the absence of the accumulation of entrepreneurial research data. Second, the translation tools used in the previous studies were translated and the meaning of the measurement tools might not be conveyed due to language differences. Therefore, it is necessary to construct a more precise scale for the accuracy of the study. Finally, complementary research should be done to identify what competitive opportunities are and what opportunities are appropriate for entrepreneurs.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.293-300
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• 2011

This study is conducted to develop an efficient transformation system via particle bombardment with PLBs (Protocorm-like bodies) in Cymbidium. For this, pCAMBIA3301 vector which carries a herbicide-resistant bar gene and gus gene as a reporter gene was used for transformation with Cymbidium cultivars 'Youngflower ${\times}$ masako' line. To select transformants, proper concentration of herbicide, PPT (phosphinotricin), should be determined. As a result, 5 mg/l of PPT was selected as a proper concentration. Further, proper conditions for particle bombardment were determined to obtain a high frequency of transformation. Results showed that 1.0 ${\mu}g$ of DNA concentration, 1,100 and 1,350 psi for helium gas pressure, 1.0 ${\mu}m$ of gold particle and 6 cm of target distance showed the best result for the particle bombardment experiment. Also, pre-treatment with combination 0.2 M sorbitol and 0.2 M mannitol for 4 hrs prior to genetic transformation increased the transformation efficiency up to 2.5 times. Using transformation system developed in this study, 3.2 ~ 4.0 transgenic cymbidium plants can be produced from 100 bombarded PLBs on average. Putative transgenic plants produced in this system confirmed the presence of the bar gene by PCR analysis. Also, leaves from randomely selected five transgenic lines were applied for Basta solution (0.5% v/v) to check the resistance to the PPT herbicide. As a result, three of them showed resistance and one of them showed the strongest resistance with the maintenance of green color as non-transformed plants showed. Using this established transformation system, more genes of interests can be introduced into Cymbidium plants by genetic transformation in the future.

• Journal of Korea Soil Environment Society
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• v.2 no.2
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• pp.81-94
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• 1997

In many solute transport studies, either flux or resident concentration has been used. Choice of the concentration mode was dependent on the monitoring device in solute displacement experiments. It has been accepted that no priority exists in the selection of concentration mode in the study of solute transport. It would be questionable, however, to accept the equivalency in the solute transport parameters between flux and resident concentrations in structured soils exhibiting preferential movement of solute. In this study, we investigate how they differ in the monitored breakthrough curves (BTCs) and transport parameters for a given boundary and flow condition by performing solute displacement experiments on a number of undisturbed soil columns. Both flux and resident concentrations have been simultaneously obtained by monitoring the effluent and resistance of the horizontally-positioned TDR probes. Two different solute transport models namely, convection-dispersion equation (CDE) and convective lognormal transfer function (CLT) models, were fitted to the observed breakthrough data in order to quantify the difference between two concentration modes. The study reveals that soil columns having relatively high flux densities exhibited great differences in the degree of peak concentration and travel time of peak between flux and resident concentrations. The peak concentration in flux mode was several times higher than that in resident one. Accordingly, the estimated parameters of flux mode differed greatly from those of resident mode and the difference was more pronounced in CDE than CLT model. Especially in CDE model, the parameters of flux mode were much higher than those of resident mode. This was mainly due to the bypassing of solute through soil macropores and failure of the equilibrium CDE model to adequate description of solute transport in studied soils. In the domain of the relationship between the ratio of hydrodynamic dispersion to molecular diffusion and the peclet number, both concentrations fall on a zone of predominant mechanical dispersion. However, it appears that more molecular diffusion contributes to the solute spreading in the matrix region than the macropore region due to the nonliearity present in the pore water velocity and dispersion coefficient relationship.

• Progress in Medical Physics
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• v.10 no.3
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• pp.133-140
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• 1999

In this paper, as a preliminary study for developing a full 3D electron dose calculation algorithm, We developed 2.5D electron dose calculation algorithm by extending 2D pencil-beam model to consider three dimensional geometry such as air-gap and obliquity appropriately. The dose calculation algorithm was implemented using the IDL5.2(Research Systems Inc., USA), For calculation of the Hogstrom's pencil-beam algorithm, the measured data of the central-axis depth-dose for 12 MeV(Siemens M6740) and the linear stopping power and the linear scattering power of water and air from ICRU report 35 was used. To evaluate the accuracy of the implemented program, we compared the calculated dose distribution with the film measurements in the three situations; the normal incident beam, the 45$^{\circ}$ oblique incident beam, and the beam incident on the pit-shaped phantom. As results, about 120 seconds had been required on the PC (Pentium III 450MHz) to calculate dose distribution of a single beam. It needs some optimizing methods to speed up the dose calculation. For the accuracy of dose calculation, in the case of the normal incident beam of the regular and irregular shaped field, at the rapid dose gradient region of penumbra, the errors were within $\pm$3 mm and the dose profiles were agreed within 5%. However, the discrepancy between the calculation and the measurement were about 10% for the oblique incident beam and the beam incident on the pit-shaped phantom. In conclusions, we expended 2D pencil-beam algorithm to take into account the three dimensional geometry of the patient. And also, as well as the dose calculation of irregular field, the irregular shaped body contour and the air-gap could be considered appropriately in the implemented program. In the near future, the more accurate algorithm will be implemented considering inhomogeneity correction using CT, and at that time, the program can be used as a tool for educational and research purpose. This study was supported by a grant (＃HMP-98-G-1-016) of the HAN(Highly Advanced National) Project, Ministry of Health & Welfare, R.O.K.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.438-446
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• 2007

The fermented soybean product, cheonggukjang, is favored by many people, partly due to its bio-functional ingredients. Since the fermentation process of cheonggukjang is mediated by enzymes, including proteases, produced by microbes, analysis of the proteome profile changes in cheonggukjang during fermentation would provide us with valuable information for fermentation optimization, as well as a better understanding of the formation mechanisms of the bio-functional substances. The soluble proteins from cheonggukjang were prepared by a phenol/chloroform extraction method, in order to remove interfering molecules for high resolution 2-D gel analysis. Proteomic analysis of the cheonggukjang different fermentation periods suggested that most of the soluble soy proteins were degraded into smaller forms within 20hr, and many microbial proteins, such as mucilage proteins, dominated the soluble protein fraction. The proteomic profile of cheonggukjang was very different from natto, in terms of the 2-D gel protein profile. Among the separated protein spots on the 2-D gels, 50 proteins from each gel were analyzed by MALDI-TOF MS and PMF for protein identification. Due to database limitations with regard to soy proteins and microbial proteins, identification of the changed proteins during fermentation was restricted to 9 proteins for cheonggukjang and 15 for natto. From de novo sequencing of the proteins by a tandem MS/MS, as well as by database searches using BLASTP, a limited number of proteins were identified with low reliability. However, the 2-D gel analysis of proteins, including protein preparation methods, remains a valuable tool to analyze complex mixtures of proteins entirely. Also, for intensive mass spectrometric analysis, it is also advisable to focus on a few of the interestingly changed proteins in cheonggukjang.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.244-250
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• 2008

To evaluate bacteriological water quality, samples were taken from drinking water dispensers placed at S company (S-C) and U highschool (U-H) in Ulsan. The medians of heterotrophic plate counts (HPCs) were 53 CFU/ml for the 74 water samples of S-C and 80 CFU/ml for the 36 cold water samples of U-H, and 38% of the S-C and 42% of the U-H samples showed HPC bacterial concentrations higher than 100 CFU/ml. Coliform bacteria were detected from one sample of S-C. To determine the major source of bacterial contamination, water samples were taken daily for $6\sim8$ days from the bottled water containers as well as the faucets of an experimental water dispenser. While the average HPCs in the bottled water containers were 33 CFU/ml for the first and 132 CFU/ml for the 2nd analysis, the HPC concentration in the cold water samples was 1,022 CFU/ml for the 2nd analysis. These results suggest that the majority of bacteria detected in the cold water samples were originated from the biofilms on the surface of water passages within the water dispensers. There was no significant increase in HPC bacterial concentrations within the bottled water container after installation on the water dispenser. We could isolate and tentatively identify 3 genera 6 species of Gram-positive and 7 genera 7 species of Gram-negative bacteria from the plate count agar plates of U-H samples. Among the isolates, 72% were observed as Gram-positive, and Micrococcus spp. was the most abundant with 54% of the total, followed by Sphingomonas paucimobilis with 16%. It appears that most of the HPC bacteria detected in water dispensers originate from indoor airborne bacteria, which may play important roles in the formation of biofilms on the surface of water passages within the water dispensers.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.4
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• pp.199-205
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• 2001

This study was conducted to figure out temperature profiles of a partially developed paddy rice canopy, which are necessary to run plant disease forecasting models. Air temperature over and within the developing rice canopy was monitored from one month after transplanting (June 29) to just before heading (August 24) in 1999 and 2001. During the study period, the temporal march of the within-canopy profile was analyzed and an empirical formula was developed for simulating the profile. A partially developed rice canopy temperature seemed to be controlled mainly by the ambient temperature above the canopy and the water temperature beneath the canopy, and to some extent by the solar altitude, resulting in alternating isothermal and inversion structures. On sunny days, air temperature at the height of maximum leafages was increased at the same rate as the ambient temperature above the canopy after sunrise. Below the height, the temperature increase was delayed until the solar noon. Air temperature near the water surface varied much less than those of the outer- and the upper-canopy, which kept increasing by the time of daily maximum temperature observed at the nearby synoptic station. After sunset, cooling rate is much less at the lower canopy, resulting in an isothermal profile at around the midnight. A fairly consistent drop in temperature at rice paddies compared with the nearby synoptic weather stations across geographic areas and time of day was found. According to this result, a cooling by 0.6 to 1.2$^{\circ}C$ is expected over paddy rice fields compared with the officially reported temperature during the summer months. An empirical equation for simulating the temperature profile was formulated from the field observations. Given the temperature estimates at 150 cm above the canopy and the maximum deviation at the lowest layer, air temperature at any height within the canopy can be predicted by this equation. As an application, temperature surfaces at several heights within rice fields were produced over the southwestern plains in Korea at a 1 km by 1km grid spacing, where rice paddies were identified by a satellite image analysis. The outer canopy temperature was prepared by a lapse rate corrected spatial interpolation of the synoptic temperature observations combined with the hourly cooling rate over the rice paddies.

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.333-339
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• 2011

The present study was performed to investigate the effects of pre- and post-weaning feeding programs on growth of pigs. A total of 24 litters (avg. 10.6 piglets/litter) born from multiparous (Yorkshire ${\times}$ Landrace) dams ${\times}$ Duroc sires were provided with neither creep feed (CF) nor milk replacer ("CON"), 200 gm CF/litter/d from the 15th day of lactation ("MIN"), or CF and milk replacer ad libitum for 7 h during the daytime from the 7th day ("MAX") through weaning at d 21 of age. Sixty-eight weanling pigs selected randomly from each of CON and MIN were provided with phases 1, 2 and 3 nursery diets for 7, 14, and 13 days, respectively, in two pens; an equal number of piglets from MAX received the same diets for 6, 10, and 18 days, respectively. Subsequently, all pigs were fed grower 1 and 2 diets sequentially up to d 95 and 135, respectively. The entire pre- and post-weaning feeding trial was repeated three times under a split-plot design of experiment. Initial and final weights and ADG of the suckling pigs did not differ between MAX/MIN and CON. However, final wt of MAX adjusted for initial wt, which was 0.17-kg less in MAX than in CON, was greater than that of CON by 0.31kg, whereas the difference between MIN and CON in final wt barely changed after the adjustment. Growth of the animals during the nursery and growing phases was not affected by the feeding program, whereas d 55 and 135 BW, as well as d 6 BW, were highly correlated with weaning weight (r=0.81, 0.57, and 0.76; P<0.001, <0.05, and <0.001, respectively). In conclusion, results suggest that provision of creep feed and milk replacer from early lactation may be effective for increasing weight gain of light piglets, but that limited provision of creep feed during late lactation or extension of the duration of phases 1 and 2 vs. 3 nursery diets for several days is unlikely to influence the growth of pigs during the corresponding and subsequent periods.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.720-727
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• 1996

Objectives: $^{201}TI$ - chloride, $^{99m}Tc$ - MIBI, $^{99m}Tc$(V) - DMSA SPECT has been used in distinguishing lung cancer from benign lesion. To compare the diagnostic efficacy of SPECT with these tumor - seeking agents, we perfonned three consecutive SPECT using $^{201}TI$, $^{99m}Tc$ - MIBI, $^{99m}Tc$(V) - DMSA in same subjects with a solitary pulmonary lesion. Methods: SPECT was carried out at 10min and 3hr for $^{201}TI$ after injection of 20mCi, and 2hr for $^{99m}Tc$ - MIBI and $^{99m}Tc$(V) - DMSA after injection of 20mCi, respectively, in 37 patients with a solitary pulmonary lesion(27 lung cancer and 10 benign diseases). In patients showing visual uptake on lesion site, we obtained the lesion - to - background(target lesion/contralateral normal lung) uptake ratio from transverse slice for each radionuclide and also calculated the retention index for $^{201}TI$. Results: The diagnostic sensitivity of $^{201}TI$, $^{99m}Tc$ - MIBI and $^{99m}Tc$(V) - DMSA SPECT to lung cancer was 100%, 96% and 73%, and the specificity was 40%, 70% and 70%, respectively. The low specificities for these agents were mainly due to high positive uptake in patients with active pulmonary tuberculosis. There were no significant differences in uptake ratios and retention index between malignant and benign lesions, and among the histologic types of lung cancer. Conclusion : $^{201}TI$ and $^{99m}Tc$ - MIBI showed higher sensitivity than $^{99m}Tc$(V) - DMSA for detecting lung cancer, but was of limited usefulness in distinguishing lung cancer from benign lesion due to low specificity, especially in area with a high prevalence of active pulmonary tuberculosis.