• Childhood Kidney Diseases
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• v.7 no.2
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• pp.166-173
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• 2003

Purpose : The cause and pathogenesis of $Henoch-Sch\"{o}nlein$ purpura has been studied for many years but the results are disappointing. Recently the hypothesis that abnormalities involving the glycosylation of the hinge region of immunoglobulin Al(IgAl) may have an important role in the pathogenesis of $Henoch-Sch\"{o}nlein$ purpura is being approved. $Henoch-Sch\"{o}nlein$ purpura is the most common vasculitis Ihat affects children and the prognosis is good. But if kidney invovement occurs, the course may be chronic and troublesome. So we evaluated children with $Henoch-Sch\"{o}nlein$ purpura especially from the point of epidemiology and clinical manifestations. Methods : Investigation of 124 children who were diagnosed with $Henoch-Sch\"{o}nlein$ purpura at Inje University Ilsan Paik Hospital from December 1999 to July 2003 was performed retrospectively through chart review. Efforts were made to get informations about the profile, epidemiology, clinical manifestations, progress of the disease and recurrence rate of patients. Results : The patients were 69 boys and 55 girls, with a mean age of $6.1{\pm}2.7$ years at the time of data collection. The male to female ratio was 1.25 : 1. The occurrence rate was much higher in autumn(from September to November, 31.5%) and winter(from December to February, 28.2%) than in spring and summer, with a peak in November. Joint involvement was shown in 66.9% of patients mostly on the foot/ankle(75.9%), knee(39.8%). Seventy(56.5%) out of 124 patients had abdominal pain and 10 patients(8.1%) showed bloody stools. Renal involvement was observed in 24 patients(19.4%) after 21.1 days on the average. IgA was elevated in 10 of 21 patients(47.6%). $C_3$ and $C_4$ levels were normal in 40 of 49 patients (81.7%) and 47 of 48 patients(97.9%), respectively Antistreptolysin-O(ASO) titer was elevated over 250 Todd units in 29 of 62 Patients(46.8%). Mycoplasma antibody titer was elevated in 21 of 49 patients(42.9%) equal or greater than 1:80. Radiologic studies were peformed in 23 patients. Seven patients(30.4%) showed bowel wall thickening and one of them received intestinal resection and anastomosis operation due to terminal ileum necrosis. Eighty four patients took steroid 1.4 mg/kg/day in average. Recurrence rate was 2.5 in 37 patients(29.8%). Conclusion : $Henoch-Sch\"{o}nlein$ purpura in childhood appears most in about 6 years of age. The occurrence rate is much higher in autumn and winter relatively. Diagnosis can be made through the perspective history taking and the inspection of clinical manifestations, but the laboratory findings are not of great help. A small portion of the patients might show abdominal pain or arthritis before purpura develops, therfore various diagnosis can be made. Radiologic evaluation should be performed to avoid surgical complications in cases accompanying abdominal pain, and long term follow up should be needed especially in patients suffering from kidney involvement. In about 30% of the patients $Henoch-Sch\"{o}nlein$ purpura would recur. Steroid can be used safely without side effects.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.711-724
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• 2003

Some growth curve models were used to fit individual growth of 1,083 Hanwoo cows born from 1970 to 2001 in Daekwanryeong branch, National Livestock Research Institute(NLRI). The effects of year-season of birth and age of dam were analyzed. In analysis of variance for growth curve parameters, the effects of birth year-season were significant for mature weight(A), growth ratio(b) and maturing rate(k)(P〈.01). The effects of age of dam were significant for growth ratio(b) but not significant for mature weight(A) and maturing rate(k). The linear term of the covariate of age at the final weights was significant for the A(P〈.01) and k(P〈.01) of Gompertz model, von Bertalanffy model and Logistic model. For the growth curve parameters fitted on individual data using Gompertz model, von Bertalanffy model and Logistic model, resulting the linear contrasts(fall-spring), Least square means of A in three nonlinear models were higher cows born at fall and A of Logistic model was significant(P〈.05) between the seasons. According to the results of the least square means of growth curve parameters by age of dam, least square means of mature weight(A) in Gompertz model was largest in 6 year and smallest estimating for 3 and 8 years of age of dam. The growth ratio(b) was largest in 2 year of age of dam and smallest estimating in 8 year. The A and k were not different by age of dam(p〉.05), On the other hand, the b was different by age of dam(p〈.01). The estimate of A in von Bertalanffy model was largest in 6 year and smallest in 8 and 9 years of age of dam. The b was largest in 2 year and tend to decline as age of dam increased. The A and k were not different by age of dam(p〉.05), On the other hand, the b was highly significant by age of dam(p〈.01).

• KSBB Journal
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• v.17 no.1
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• pp.73-79
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• 2002

The method to optimize the microbial production of ethanol from CO using Clostridium ljungdahlii was developed. The kinetic parameter study on CO conversion with Clostridium ljungdahlii was carried out and maximum CO conversion rate of 37.14 mmol/L-hr-O.D. and $K_{m}$ / of 0.9516 atm were obtained. It was observed that method of two stage fermentation, which consists of cell growth stage and ethanol production stage, was effective to produce ethanol. When pH was shifted from 5.5 to 4.5 and ammonium solution was supplied to culture media as nitrogen source at ethanol production stage, the concentration of ethanol produced was increased 20 times higher than that without shift. Ethanol production from CO in a fermenter with Clostridium ljungdahlii was optimized and the concentration of ethanol produced was 45 g/L and maximun ethanol productivity was 0.75 g ethanol/L-hr.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.218-233
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• 2022

The long-term (1986~2020) predictability of the number of days of heat and cold damages for each growth stage of soybean is evaluated using the daily maximum and minimum temperature (Tmax and Tmin) data produced by Pusan National University Coupled General Circulation Model (PNU CGCM)-Weather Research and Forecasting (WRF). The Predictability evaluation methods for the number of days of damages are Normalized Standard Deviations (NSD), Root Mean Square Error (RMSE), Hit Rate (HR), and Heidke Skill Score (HSS). First, we verified the simulation performance of the Tmax and Tmin, which are the variables that define the heat and cold damages of soybean. As a result, although there are some differences depending on the month starting with initial conditions from January (01RUN) to May (05RUN), the result after a systematic bias correction by the Variance Scaling method is similar to the observation compared to the bias-uncorrected one. The simulation performance for correction Tmax and Tmin from March to October is overall high in the results (ENS) averaged by applying the Simple Composite Method (SCM) from 01RUN to 05RUN. In addition, the model well simulates the regional patterns and characteristics of the number of days of heat and cold damages by according to the growth stages of soybean, compared with observations. In ENS, HR and HSS for heat damage (cold damage) of soybean have ranged from 0.45~0.75, 0.02~0.10 (0.49~0.76, -0.04~0.11) during each growth stage. In conclusion, 01RUN~05RUN and ENS of PNU CGCM-WRF Chain have the reasonable performance to predict heat and cold damages for each growth stage of soybean in South Korea.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.352-362
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• 2023

Harvest time is one of the most important determining factors of seed quality, especially for species that produce seeds over irregular and long-term periods, such as Larix kaempferi. A cone collection plan must be established to increase seed production efficiency and stable mass production. We investigated seed qualities such as seed efficiency, germination rate, and T₅₀ (germination speed), with 7 or 8 cone collection times at a clonal seed orchard of L. kaempferi in Chungju between 2021 and 2022. A multivariate analysis was then performed for the collected data. In early August, decreases in the moisture contents and browning of cones were observed. These were followed by a decrease in germination rate, with a peak at the end of September, but no clear trend was observed. The later the cones were harvested, the better the seed vigor (T₅₀). However, the seed yield and efficiency decreased owing to increases in seed scattering and the number of insect-damaged seeds. As a result, the optimal time of seed harvest for the seed orchard was in early August. To produce uniform seedlings, insect damage must be reduced through timely control and harvest cones in early September. This shows that the degree of browning and moisture content of cones can be used as indicators of the timing of cone collection in L. kaempferi seed orchards.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.215-235
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• 1996

The thermal analysis by mathematical model simulation makes it possible to reasonably predict heating and/or cooling requirements of certain greenhouses located under various geographical and climatic environment. It is another advantages of model simulation technique to be able to make it possible to select appropriate heating system, to set up energy utilization strategy, to schedule seasonal crop pattern, as well as to determine new greenhouse ranges. In this study, the control pattern for greenhouse microclimate is categorized as cooling and heating. Dynamic model was adopted to simulate heating requirements and/or energy conservation effectiveness such as energy saving by night-time thermal curtain, estimation of Heating Degree-Hours(HDH), long time prediction of greenhouse thermal behavior, etc. On the other hand, the cooling effects of ventilation, shading, and pad ||||&|||| fan system were partly analyzed by static model. By the experimental work with small size model greenhouse of 1.2m$\times$2.4m, it was found that cooling the greenhouse by spraying cold water directly on greenhouse cover surface or by recirculating cold water through heat exchangers would be effective in greenhouse summer cooling. The mathematical model developed for greenhouse model simulation is highly applicable because it can reflects various climatic factors like temperature, humidity, beam and diffuse solar radiation, wind velocity, etc. This model was closely verified by various weather data obtained through long period greenhouse experiment. Most of the materials relating with greenhouse heating or cooling components were obtained from model greenhouse simulated mathematically by using typical year(1987) data of Jinju Gyeongnam. But some of the materials relating with greenhouse cooling was obtained by performing model experiments which include analyzing cooling effect of water sprayed directly on greenhouse roof surface. The results are summarized as follows : 1. The heating requirements of model greenhouse were highly related with the minimum temperature set for given greenhouse. The setting temperature at night-time is much more influential on heating energy requirement than that at day-time. Therefore It is highly recommended that night- time setting temperature should be carefully determined and controlled. 2. The HDH data obtained by conventional method were estimated on the basis of considerably long term average weather temperature together with the standard base temperature(usually 18.3$^{\circ}C$). This kind of data can merely be used as a relative comparison criteria about heating load, but is not applicable in the calculation of greenhouse heating requirements because of the limited consideration of climatic factors and inappropriate base temperature. By comparing the HDM data with the results of simulation, it is found that the heating system design by HDH data will probably overshoot the actual heating requirement. 3. The energy saving effect of night-time thermal curtain as well as estimated heating requirement is found to be sensitively related with weather condition: Thermal curtain adopted for simulation showed high effectiveness in energy saving which amounts to more than 50% of annual heating requirement. 4. The ventilation performances doting warm seasons are mainly influenced by air exchange rate even though there are some variations depending on greenhouse structural difference, weather and cropping conditions. For air exchanges above 1 volume per minute, the reduction rate of temperature rise on both types of considered greenhouse becomes modest with the additional increase of ventilation capacity. Therefore the desirable ventilation capacity is assumed to be 1 air change per minute, which is the recommended ventilation rate in common greenhouse. 5. In glass covered greenhouse with full production, under clear weather of 50% RH, and continuous 1 air change per minute, the temperature drop in 50% shaded greenhouse and pad ＆ fan systemed greenhouse is 2.6$^{\circ}C$ and.6.1$^{\circ}C$ respectively. The temperature in control greenhouse under continuous air change at this time was 36.6$^{\circ}C$ which was 5.3$^{\circ}C$ above ambient temperature. As a result the greenhouse temperature can be maintained 3$^{\circ}C$ below ambient temperature. But when RH is 80%, it was impossible to drop greenhouse temperature below ambient temperature because possible temperature reduction by pad ||||&|||| fan system at this time is not more than 2.4$^{\circ}C$. 6. During 3 months of hot summer season if the greenhouse is assumed to be cooled only when greenhouse temperature rise above 27$^{\circ}C$, the relationship between RH of ambient air and greenhouse temperature drop($\Delta$T) was formulated as follows : $\Delta$T= -0.077RH＋7.7 7. Time dependent cooling effects performed by operation of each or combination of ventilation, 50% shading, pad ＆ fan of 80% efficiency, were continuously predicted for one typical summer day long. When the greenhouse was cooled only by 1 air change per minute, greenhouse air temperature was 5$^{\circ}C$ above outdoor temperature. Either method alone can not drop greenhouse air temperature below outdoor temperature even under the fully cropped situations. But when both systems were operated together, greenhouse air temperature can be controlled to about 2.0-2.3$^{\circ}C$ below ambient temperature. 8. When the cool water of 6.5-8.5$^{\circ}C$ was sprayed on greenhouse roof surface with the water flow rate of 1.3 liter/min per unit greenhouse floor area, greenhouse air temperature could be dropped down to 16.5-18.$0^{\circ}C$, whlch is about 1$0^{\circ}C$ below the ambient temperature of 26.5-28.$0^{\circ}C$ at that time. The most important thing in cooling greenhouse air effectively with water spray may be obtaining plenty of cool water source like ground water itself or cold water produced by heat-pump. Future work is focused on not only analyzing the feasibility of heat pump operation but also finding the relationships between greenhouse air temperature(T$_{g}$ ), spraying water temperature(T$_{w}$ ), water flow rate(Q), and ambient temperature(T$_{o}$).

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.6
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• pp.59-76
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• 2019

Most technology-based entrepreneurship(TBE) go through an process of decline or disappear without overcoming the valley of death(VoD). The purpose of this study is to identify the growth dimension of TBE and to test the influence of firms activities on firms growth over time. This study identified the two-dimensional growth dimension divided by size and profit through exploratory factor analysis(EFA) of a number of growth indicators. Then, we defined the discrete state of growth firm in four states, divided by size and profit, and five states, including the closure of business. Multi-nomial logit model is used to predict the effect of TBE activities on a discrete state of growth firm(size×profit, closure of business) based on multiple independent variables. The independent variables are based on five representative firms activities: employment, marketing, R&D, financial activities, and general management activities. The growth stage of TBE over time has been categorized into three stages: early stage, middle stage, and late stage of business, taking into account the main periods during which the survival rate of startups sharply decreases. The analytical data of this study was based on the secondary data of the start-up supporting companies of government and public institutions. The subjects of analysis were TBE within 10 years. As a result of the empirical analysis, the employment and marketing activities of TBE show that early and mid-term activities had an effect on the state of firms growth. However, if there is a difference, employment activities have both positive and negative effects, while marketing activities have only a positive effect on size and profit growth. And besides, R&D activities, financial activities, and general management activities throughout the entire process of firms growth were found to be firms activities that have both positive and negative effects on firms growth. In addition, the age of the founder, the firms' industry, and the geographic location of the firms, which are general characteristics of the company, were found to have a distinctive effect on the growth status of the firms according to the growth stage.

• Korean Journal of Ecology and Environment
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• v.45 no.3
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• pp.271-277
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• 2012

The present study was conducted to assess the suitability of domestic natural waters as a Daphnia magna culture medium. In order to assess survival rate and reproductive output, young female daphnids (parent animals), aged less than 24 hours at the start of the test and produced in the Elendt M4 medium, were exposed to Elendt M4 medium, de-chlorinated tap water, and natural mineral water for 21 days. D. magna cultured in Elendt M4 medium (reference medium) and natural mineral water met the criteria of OECD No. 211, Daphnia magna Reproduction Test Guidelines in terms of percent adult survival, first day of reproduction, and average young production. However, the mortalities of adult daphnids observed in de-chlorinated tap water were more than 20% in two reproduction tests for 21 days. Mortality was observed on exposure days 13, 15, and 18 in de-chlorinated water. The use of D. magna is recommended in water of hardness >80 mg $CaCO_3\;L^{-1}$. However, the hardness of de-chlorinated tap water used in the present study was 50~53 mg $CaCO_3\;L^{-1}$. Therefore, it is judged that the delayed mortalities observed in de-chlorinated tap water were caused by a rapid decreased in hardness when the medium was changed from Elendt M4 to de-chlorinated tap water. When D. magna is cultured using domestic natural waters (underground water, surface water, and de-chlorinated water), the quality-control (QC) data should be maintained through a standardization for health assessment method, toxicity test method using reference chemical, test intervals of reference toxicant toxicity test, and data treatment and interpretation. In the long term, national research programs are needed for the development of test species which are representative of domestic aquatic environmental conditions among indigenous daphnids.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.742-748
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• 2004

The On-X valve was recently introduced. It was the aim of this study to assess the safety and feasibility from the data derived from 28 patients who underwent aortic and/or mitral valve replacement with this prosthesis in National Medical Center. Material and Method： From May 1999 and May 2003, a series of 28 consecutive patients who had been implanted with 32 On-X prosthesis were reviewed, The operative procedure comprised of 12 MVR, 10 AVR and 6 DVR. The study followed the guidelines of AATS/STS. Mean follow-up was 27 months (total 04 patient-years). Result: Early ($\leq$30 days) mortality was 7.44% (2/28) and no late mortality occurred in the study. Total actuarial freedom from mortality at 2 years was 92.86$\pm$4.87% for all cases, 100% for MVR, 90$\pm$9.49% for AVR, and 83.3$\pm$1.52% for DVR. Thromboembolic event occurred in 2 MVR patients and that was the only complication; therefore, the linearized incidence of valve related complications was 3.17%/ patient-years for all cases and 6.5%/patient-years for MVR and the actuarial freedom from valve related complications at 2 years was 84.85$\pm$10.75%. Preoperatively, 24 (85.71%) patients were in NYHA functional class III or IV but postoperatively, 25 (89,29%) patients were in NYHA functional class I or II. The levels of hemoglobin, hematocrit, serum LDH, reticulocyte rate and indirect bilirubin were all within normal range at postoperative 3 month. In mitral position, the peak gradient was 6.1$\pm$1.8 mmHg and the mean gradient was 3.0$\pm$0.6 mmHg and EOA were 2.54$\pm$0.56 $m^2$, 2.39$\pm$0.73 $m^2$, 2.34$\pm$0.55 $m^2$, 2.40$\pm$0.63 $m^2$ at 27 mm, 29 mm, 31 mm, 33 mm respectively. In aortic postion, the peak gradient was 21.1 $\pm$14.12 mmHg and the mean gradient was 12.3$\pm$6.52 mmHg. Conclusion: Since there was no significant difference in the postoperative mortality, valve related complications and echocardiographic hemodynamic data compared to standard bileaflet design and since there was an improvement in the NYHA functional class and normal values of hemolytic indicators, it can be assumed that On-X valve is safe and feasible. However, accumulation of cases and long-term follow-up of this patient group is needed to establish this result.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.143-150
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• 2020

This research is intended to identify how office worker's recognition of strength affects the intention of starting a business when it is used as a medium for utilizing strength. The survey period was conducted for two months from January 17, 2019 to March 8, 2019. In order to achieve the object of this study, a significant number of employees have been collected nationwide, and 287 office workers were analyzed after collecting 300 questionaires, excluding 13 office workers who were not sincere. The significant data were analyzed by utilizing the structural equation and technical statistics and by verifying the conformity of structural model and measurement model and by investigating the relationship between variables. The results of this study are summarized as follows: First, employee's perception of strength has been found to have a significant effect on the utilizing of strength. Second, the use of workers' strengths has been found to have a significant effect on the intention of starting a business. Third, it has been confirmed that in the relationship between the employee's perception of strength and intention to start a business, the recognition of strength has a significant effect on the intention of starting a business only through the use of strength. Most office workers are nervous about the future and make various plans. The time to live after retirement is getting longer and jobs and working hours are shrinking at an alarming rate. According to the analysis on the status of small business owners in the mid-term of 2017 data, the average monthly operating profit of small business owners across the country is decreasing over the years, and most start-ups are subsistence-type start-ups, and they decide to start their own businesses because they have no other choice than start-ups. As the number of small business owners suffering from financial difficulties has increased since the financial crisis and insecurity of job is pushing those with financial difficulties after retirement to the battleground of the start-up market, the result of this research suggest that the workers need to recognize their own strength and enhance the importance of utilizing the strength.