• Childhood Kidney Diseases
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• v.9 no.1
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• pp.21-30
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• 2005

Purpose : Metabolic bone diseases have been mai or problems in children with renal diseases and steroid treatment is the main precipitating factor reducing bone mineral density(BMD). This study was performed to assess the prevalence of osteoporosis and to evaluate the clinical factors associated with decreased BMD in children with renal diseases. Methods : Forty-four children with renal diseases who were diagnosed at the Pediatric no phrology division of Ajou University hospital since Oct. 1994 were included. Using a new quantitative ultrasound device, BMD and the prevalence of osteoporosis were evaluated. The clinical and serological data were analyzed in association with decreased BMD. Results : A total of 44 patients were evaluated. The age at initial diagnosis was 6.7$\pm$4.2 years. At the time of evaluation, the chronological and bone age was 9.3$\pm$4.2 years and 8.2 $\pm$ 4.6 years, respectively. The renal diseases included nephrotic syndrome 24(54.5%), Henoch Schonlein purpura nephritis 7(15.9%), IgA nephropathy 6(13.9%), reflux nephropathy(RN) 2 (4.5%), and other renal disease 5(%). The prevalence of osteoporosis was 11%. There was no difference in the clinical factors between the long-term and the short-term treated steroid groups. Conclusion : The prevalence of osteoporosis was 12% in 44 children with renal diseases No significant factor was found in association with decreased BMD and there was no relationship between osteoporosis and steroid usage duration or cumulative dose. A new quantitative ultrasound, which is relatively easy to perform, especially in children, is expected to be in common use and will enable clinicians to evaluate metabolic bone disorders with ease.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.702-708
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• 2011

There are considerable areas of wet paddy fields in Korea that requires improvement of its drainage system. In poorly drained sloping paddy fields, upland crops can be damaged by either rainfall or capillary rise of the water table caused by percolating water beneath the upper fields during summertime rainy season. The purpose of this study is to evaluate excess water stress of soybean yield by drainage systems. Four drainage methods namely open ditch, vinyl barrier, pipe drainage and tube bundle were installed within 1-m position at the lower edge of the upper paddy fields. Stress Day Index (SDI) approach was developed to quantify the the cumulative effect of stress imposed on a soybean yield throughout the growing season. SDI was determined from a stress day factor (SD) and a crop susceptibility factor (CS). The stress day factor is a measure degree and duration of stress of the ($SEW_{30}$). The crop susceptibility factor (CS) depends of a given excess water on crop stage. The results showed that SDI used to represent the moisture stress index was most low on the pipe drainage 64.75 compared with the open ditch 355.4, vinyl barrier 271.55 and tube bundle 171.55. Soybean grain yield increased continuously with the rate of 3% in Vinyl Barrier, 32% in Pipe Drainage and 16% in Tube Bundle.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.256-266
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• 2022

Empirical models including the Angstrom-Prescott (AP) model have been used to estimate solar radiation at sites, which would support a wide use of crop models. The objective of this study was to estimate two sets of solar radiation estimates using the AP coefficients derived for climate zone (AP_Frere) and specific site (AP_Choi), respectively. The daily solar radiation was estimated at 18 sites in Korea where long-term measurements of solar radiation were available. In the present study, daily solar radiation and sunshine duration were collected for the period from 2012 to 2021. Daily weather data including maximum and minimum temperatures and rainfall were also obtained to prepare input data to a process-based crop model, CERES-Rice model included in Decision Support System for Agrotechnology Transfer (DSSAT). It was found that the daily estimates of solar radiation using the climate zone specific coefficient, SFrere, had significantly less error than those using site-specific coefficients S_Choi (p<0.05). The cumulative values of S_Frere for the period from march to September also had less error at 55% of study sites than those of S_Choi. Still, the use of S_Frere and S_Choi as inputs to the CERES-Rice model resulted in slight differences between the outcomes of crop growth simulations, which had no significant difference between these outputs. These results suggested that the AP coefficients for the temperate climate zone would be preferable for the estimation of solar radiation. This merits further evaluation studies to compare the AP model with other sophisticated approaches such as models based on satellite data.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.189-197
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• 2022

This study was conducted to compare the egg productivity, egg quality, and blood characteristics of laying hens with different laying rates, and the frequency and cumulative duration of the sitting behavior observed before laying was investigated. Twelve 45-week-old Hy-Line Brown laying hens were randomly assigned to two treatment groups with three replicates. Treatment groups were classified as layers laying over 80%(high egg performance layers; HEP) and layers laying below 50%(poor egg performance layers; PEP). The experiment lasted 4 weeks. HEP showed higher hen-house egg production ratio and egg mass and lower feed conversion ratio(FCR) (P<0.05) compared with PEP, although egg weight was higher in PEP (P<0.05). In terms of egg quality, PEP showed differences in eggshell quality (eggshell color, eggshell thickness, and eggshell weight) (P<0.05). Additionally, HEP showed high triglycerides(TG), and PEP showed high alanine transaminase(ALT) level (P<0.05) in serum collected in the morning. In the afternoon, the HEP showed higher lactate dehydrogenase(LDH) levels (P<0.05). No differences in the Ca: P ratio were observed between layers with different laying rates. One hour before egg laying, HEP exhibited sitting behavior 4 times on average, each lasting 25 minutes. In conclusion, egg production and quality differ between HEP and PEP, and HEP showed frequent sitting behavior before egg laying. However, additional research is necessary to explore approaches other than specific behavioral observation to distinguish poor layers in the flock for application in farms.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.520-530
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• 2011

This study was carried out to evaluate the possibility of rice double cropping in Korea by assessing the growth and yield performance of rice cultivars transplanted at the extremely-early date. When the transplanted rice seedling was exposed to low temperature below 0℃, the survival rate decreased drastically. However, short exposure to below 0℃ one or two times did not damage transplanted rice seedling so severely. Thus, the earliest transplanting in spring would be possible when minimum temperature rises above 0℃. Compared with the conventional seedling nursery tray (CSNT), seedling rearing with the potted nursery tray was more effective for increasing leaf age and seedling dry weight during nursery period. In the first rice cropping, rice cultivation with seedlings reared in PSNT showed shorter growth duration and cumulative temperature from transplanting to heading than that with seedlings reared in CSNT. The earliest heading date on July 4 in Jinbuolbyeo was earlier by two to three days than that of Dunaebyeo. If rice has not exposed to cold damage, the earliest heading date of Jinbujolbyeo can advance to June 30 or July 1. In this case, rice harvest would be possible on August 5, enabling the rice transplanting of the second rice cropping before August 10. At transplanting time with low temperature damage rice yield were less than 400 kg/10a while rice yield exceeded 400 kg/10a at transplanting time without low temperature damage.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.323-331
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• 2000

Purpose: Brain metastases are present in approximately 10-16% of small cell lung cancer patients at diagnosis. Brain metastasis is an important clinical problem associated with increasing the survival rate, with a cumulative incidence of up to 80% in patients surviving 2 years. Prophylactic cranial irradiation(PCI) reduces the incidence of brain matastasis and may prolong survival in patients with limited small-cell lung cancer who achieved complete remission. This study was performed to analyze the incidence of brain metastasis, survival and clinical aspects after PCI in patients with limited small-cell lung cancer who achieved complete remission. Methods : Between 1989 and 1999, forty-two patients with limited small-cell lung cancer who achived achieved complete remission after therapy were enrolled into this study retrospectively. All patients received etoposide and cisplatin(VPP) alternating with cytoxan, adriamycin, and vincristine(CAV) every 3 weeks for at least 6 cycles initially. All patients received thoracic radiotherapy: concurrent(38.1%) and sequential(61.9%). All patients received late PCI. Results : Most patients(88.1%) were men, and the median age was 58 years. The median follow-up duration was 18.1 months. During the follow-up period, 57.1% of the patients developed relapse. The most frequent site of relapse was chest(35.7%), followed by brain(14.3%), liver(11.9%), adrenal gland(44%), and bone(2.2%). With the Kaplan-Meier method, the average disease-free interval was 1,090 days(median 305 days). The average time to development of brain relapse after PCI and other sites relapse(except brain) were 2,548 days and 1,395 days(median 460 days), respectively. The average overall survival was 1,233 days(median 634 days, 21.1 months), and 2-year survival rates was 41.7%. The average overall survival in the relapse group was 642 days(median 489 days) and in the no relapse group was 2,622 days(p<0.001). The average overall survival in the brain relapse group was 928 days(median 822 days) and in the no brain relapse group was 1,308 days(median 634 days)(p=0.772). In most patients(85.7%), relapse(except brain) or systemic disease was the usual cause of death. Brain matastasis was the cause of death in 14.3% of the cases. Conclusions : We may conclude that PCI reduces and delays brain metastasis in patients with limited small cell lung cancer who achieved complete remission. We found decreased survival in relapse group but, no significant survival difference was noted according to brain matastasis. And relapse(except brain) or systemic disease was the usual cause of death. In order to increase survival, new treatment strategies for control methods for relapse and systemic disease are required.

• Tuberculosis and Respiratory Diseases
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• v.45 no.5
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• pp.1012-1021
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• 1998

Background : It is known that airway inflammation is present in most patients with asthma, but the relationship between symptoms and the severity and nature of airway inflammation has not been established. Cough variant asthma is defined as an asthma in which the dominant symptom is cough, and the condition can be successfully treated with inhaled steroids. This study was performed to evaluate the time course of bronchial responsiveness according to an inhaled anti-inflammatory therapy and the factors which affect the resolution of bronchial responsiveness, and an efficacy of nedocromil to cough asthma. Method: A prospective study for the investigation of bronchial responsiveness according to an inhaled anti-inflammatory treatment in sixty-one cough asthmatics was performed. Twenty-three entered budesonide ($400{\mu}g{\times}2/day$), twenty-two entered nedocromil ($4mg{\times}2/day$) and sixteen patients entered combined group. The bronchial hyperresponsiveness (BHR) was estimated by methacholine challenge test using counted breath method. The symptom was estimated by 'symptom score'. Reevaluation of BHR and symptom was performed at 2 month after treatment, and if BHR was not resoluted at this time, regarded as a non-responder, and then follow-up of BHR and symptom was performed at 4- and/or 6 month after treatment. Results: The improvement of BHR and symptom was significant in 2 month (p<0.05), but there was no change of them during follow-up period of 4- and/or 6 month in non-responders. In comparison of allergic markers such as serum total IgE, peripheral eosinophil count and skin test reactivity between responders and non-responders, there was no difference in each other. However, in comparison of other factors such as cumulative pack-years, symptom duration, age, gender, and the initial degree of PC20, there was a significant difference in each other(p<0.05). The percent of patients with the resolution of BHR in 2 month was not different in each group(p=0.95). There was no significant difference in the degree of improvement of BHR and symptom in each group. Conclusion: Bronchial responsiveness and symptom was not significantly improved in non-responders during follow-up period of 4- and/or 6 month. The effect of inhaled nedocromil was equivalent to that of inhaled steroid in cough asthmatics, and the response to combined treatment is not superior to that achieved by either of these agents used alone.

• Journal of Preventive Medicine and Public Health
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• v.30 no.2 s.57
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• pp.381-391
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• 1997

In an epidemiological study of metal workers exposed to metalworking fluids (MWF), the prevalence time of Evolution, seasonal occurrence and clinical type of contact dermatitis were investigated. Compostional analysis of MWF with HPLC, dermatological examination and two consecutive questionnaire surveys were conducted. Study population was divided into two groups ; workers contact to cutting oil and workers contact to rust preventive oil. In the analysis of MWF, aliphatic hydrocarbons, having 12-20 carbons, was most common composition(49.04%) of cutting oil otherwise, major contents (90.99%) of the rust preventives oil were aliphatic hydrocarbons composed of 6-9 carbons. The frequency (point prevalence) of contact dermatitis(CD) was 7(12.7 per 100 subjects) in the dermatological examination of 55 workers. As the result of second survey for contact dermatitis, cumulative prevalence of oil working full-time and recent 1 year prevalence in two groups were 28.0, 16.7 and 15.1, 12.5 per 100 subjects. There were no difference in the prevalence of CD by oil, age, oil contact duration. Summer is the most common evolution season in workers exposed to cutting oil, but not in workers exposed to rust preventive oil. Major clinical type of CD was erythematous papules in both groups. It presents the importance of preventive measures that 51.1% suffer from contact dermatitis had medical care at their own expense, and 47.1% of them felt serious about their contact dermatitis. From the fact that 68.6% think cotton gloves protective apparatus, we emphasize the need for health education.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.389-398
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• 1998

Purpose : To evaluate the role of conventional postoperative adjuvant radiotherapy in the management of supratentorial malignant glioma and to determine favorable prognostic factors affecting survival. Materials and Methods : From Sep. 1985 to Mar. 1997, the number of eligible patients who received postoperative radiotherapy completely was 69. They ranged in age from 7 to 66 years (median, 47). Forty-two (61$\%$) patients were glioblastoma multiforme and the other 27 (39$\%$) were anaplastic astrocytoma. Twenty patients (29$\%$) had Karnofsky score equal or more than 80 preoperatively. Forty-three patients (62$\%$) had symptom duration equal or less than 3 months. Twenty-four patients (35$\%$) had gross total resection and forty patients(58$\%$) had partial resection, the remaining five patients (7$\%$) had biopsy only. Radiotherapy dose ranged from 50.4 Gy to 61.2 Gy (median, 55.8; mode, 59.4) with fraction size of 1 8 Gy-2.0 Gy for 33-83 days(median, 48) except three patients delivered 33, 36, 39 Gr, respectively with fraction size of 3.0 Gy due to poor postoperative performance status. Follow-up rate was 93$\%$ and median follow-up period was 14 months. Results : Overall survival rate at 2 and 3 years and median survival were 38$\%$, 20$\%$, and 16 months for entire patients; 67$\%$, 44$\%$, and 34 months for anaplastic astrocytoma; 18$\%$, 4$\%$, and 14 months for glioblastoma multiforme, respectively (p=0.0001). According to the extent of surgery, 3-year overall survival for gross total resection, partial resection, and biopsy only was 38$\%$, 11$\%$, and 0$\%$, respectively (p=0.02) The 3-year overall survival rates for patients age 40>, 40-59, and 60< were 52$\%$, 8$\%$, and 0$\%$, respectively (p=0.0007). For the variate of performance score 80< vs 80>, the 3-year survival rates were 53$\%$ and 9$\%$, respectively (p=0.008). On multivariate analysis including covariates of three surgical and age subgroups as above, pathology, extent of surgery and age were significant prognostic factors affecting overall survival. On another multivariate analysis with covariates of two surgical (total resection vs others) and two a9e (50> vs 50<) subgroups, then, pathology, extent of surgery and performance status were significant factors instead of age and 3-year cumulative survival rate for the five patients with these three favorable factors was 100$\%$ without serious sequela. Conclusion : We confirmed the role of postoperative conventional radiotherapy in the management of supratentorial malignant glioma by improving survival as compared with historical data of surgery only. Patients with anaplastic astrocytoma, good performance score, gross total resection and/or young age survived longest. Maximum surgical resection with acceptable preservation of neurologic function should be attempted in glioblastoma patients, especially in younger patients. But the survival of most globlastoma patients without favorable factors is still poor, so other active adjuvant treatment modalities should be tried or added rather than conventional radiation treatment alone in this subgroup.

• Asia Marketing Journal
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• v.14 no.2
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• pp.157-176
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• 2012

Brand switching data frequently used in market structure analysis is adequate to analyze non- durable goods, because it can capture competition between specific two brands. But brand switching data sometimes can not be used to analyze goods like automobiles having long term duration because one of main assumptions that consumer preference toward brand attributes is not changed against time can be violated. Therefore a new type of data which can precisely capture competition among durable goods is needed. Another problem of using brand switching data collected from actual purchase behavior is short of explanation why consumers consider different set of brands. Considering above problems, main purpose of this study is to analyze market structure for durable goods with consideration set. The author uses exploratory approach and latent class clustering to identify market structure based on heterogeneous consideration set among consumers. Then the relationship between some factors and consideration set formation is analyzed. Some benefits and two demographic variables - age and income - are selected as factors based on consumer behavior theory. The author analyzed USA automotive market with top 11 brands using exploratory approach and latent class clustering. 2,500 respondents are randomly selected from the total sample and used for analysis. Six models concerning market structure are established to test. Model 1 means non-structured market and model 6 means market structure composed of six sub-markets. It is exploratory approach because any hypothetical market structure is not defined. The result showed that model 1 is insufficient to fit data. It implies that USA automotive market is a structured market. Model 3 with three market structures is significant and identified as the optimal market structure in USA automotive market. Three sub markets are named as USA brands, Asian Brands, and European Brands. And it implies that country of origin effect may exist in USA automotive market. Comparison between modal classification by derived market structures and probabilistic classification by research model was conducted to test how model 3 can correctly classify respondents. The model classify 97% of respondents exactly. The result of this study is different from those of previous research. Previous research used confirmatory approach. Car type and price were chosen as criteria for market structuring and car type-price structure was revealed as the optimal structure for USA automotive market. But this research used exploratory approach without hypothetical market structures. It is not concluded yet which approach is superior. For confirmatory approach, hypothetical market structures should be established exhaustively, because the optimal market structure is selected among hypothetical structures. On the other hand, exploratory approach has a potential problem that validity for derived optimal market structure is somewhat difficult to verify. There also exist market boundary difference between this research and previous research. While previous research analyzed seven car brands, this research analyzed eleven car brands. Both researches seemed to represent entire car market, because cumulative market shares for analyzed brands exceeds 50%. But market boundary difference might affect the different results. Though both researches showed different results, it is obvious that country of origin effect among brands should be considered as important criteria to analyze USA automotive market structure. This research tried to explain heterogeneity of consideration sets among consumers using benefits and two demographic factors, sex and income. Benefit works as a key variable for consumer decision process, and also works as an important criterion in market segmentation. Three factors - trust/safety, image/fun to drive, and economy - are identified among nine benefit related measure. Then the relationship between market structures and independent variables is analyzed using multinomial regression. Independent variables are three benefit factors and two demographic factors. The result showed that all independent variables can be used to explain why there exist different market structures in USA automotive market. For example, a male consumer who perceives all benefits important and has lower income tends to consider domestic brands more than European brands. And the result also showed benefits, sex, and income have an effect to consideration set formation. Though it is generally perceived that a consumer who has higher income is likely to purchase a high priced car, it is notable that American consumers perceived benefits of domestic brands much positive regardless of income. Male consumers especially showed higher loyalty for domestic brands. Managerial implications of this research are as follow. Though implication may be confined to the USA automotive market, the effect of sex on automotive buying behavior should be analyzed. The automotive market is traditionally conceived as male consumers oriented market. But the proportion of female consumers has grown over the years in the automotive market. It is natural outcome that Volvo and Hyundai motors recently developed new cars which are targeted for women market. Secondly, the model used in this research can be applied easier than that of previous researches. Exploratory approach has many advantages except difficulty to apply for practice, because it tends to accompany with complicated model and to require various types of data. The data needed for the model in this research are a few items such as purchased brands, consideration set, some benefits, and some demographic factors and easy to collect from consumers.