• Journal of The Korean Association of Information Education
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• v.25 no.2
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• pp.239-247
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• 2021

In elementary schools, software education became essential and the importance of artificial intelligence education was emphasized. The software private education market is gradually growing, but related research is insufficient. In addition to the software education provided by public education, a basic investigation and analysis on the reasons and perceptions of parents participating in software private education are required. This study surveyed the reasons and necessity of participating in software private education, and perceptions of software education for parents of elementary school students who participated in software private education. As a result of the study, the biggest reason for participating in software private education was the lack of time and environment to provide software education in elementary schools. It was analyzed that the need for private software education had the greatest impact on the need for a separate formal subject for software education.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.3
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• pp.119-126
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• 2023

Sarcopenia is not well known enough to be classified as a disease in 2021 in Korea, but it is recognized as a social problem in developed countries that have entered an aging society. The diagnosis of sarcopenia follows the international standard guidelines presented by the European Working Group for Sarcopenia in Older People (EWGSOP) and the d Asian Working Group for Sarcopenia (AWGS). Recently, it is recommended to evaluate muscle function by using physical performance evaluation, walking speed measurement, and standing test in addition to absolute muscle mass as a diagnostic method. As a representative method for measuring muscle mass, the body composition analysis method using DEXA has been formally implemented in clinical practice. In addition, various studies for measuring muscle mass using abdominal images of MRI or CT are being actively conducted. In this paper, we develop an AI image segmentation model based on abdominal images of CT with a relatively short imaging time for the diagnosis of sarcopenia and describe the multicenter validation. We developed an artificial intelligence model using U-Net that can automatically segment muscle, subcutaneous fat, and visceral fat by selecting the L3 region from the CT image. Also, to evaluate the performance of the model, internal verification was performed by calculating the intersection over union (IOU) of the partitioned area, and the results of external verification using data from other hospitals are shown. Based on the verification results, we tried to review and supplement the problems and solutions.

• Korean Journal of Environment and Ecology
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• v.28 no.1
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• pp.90-98
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• 2014

This study was carried out to provide basic data. his research conducted the survey using face to face survey and board survey during about 2 months from Oct. to Nov. in 2009 for users of Bongje Mt., a small-sized mountain at downtown, and Acha Mt., a big-sized mountain at outskirt so as to compare the differences of using behavior by forms and size of urban forest in living area of Seoul. Characteristics of urban forest users, using behavior, demands and satisfaction of facilities and management and pass pattern were set as research items. The thing in common for using behavior is that both genders of main users were in more than 40s~60s. They showed the highest using rate from 7 a.m. to 12 p.m. and high rate for using nearly everyday or visiting two or three times per a week. In addition, it's judged that the accessibility from dwelling area to entrance of urban forest in living area is good and satisfaction for the standard of facilities and their management in forest way was relatively low. For the complement and essential facilities, 'sanitary facilities' showed the highest rate. For the differences of using behavior, most of Bongje Mt. users were residents living within a 2km radius (under the standard of walking) and they moved by average 1.3km. And, they preferred short-time activities of about 24 minutes. On the other hand, main users of Acha Mt. were residents living within a 4km radius (under the standard of walking) and people of other regions. and 60% of them preferred the passage route taking 3hours half over 6km. Through the survey on using behavior of urban forest in living area of Seoul, with different using form and forest size, introduction of using program for main users or managing method of differentiations for introduced facility's management should be properly applied. Especially, urban forest should be systematically managed like park green as expected that residents's using of urban forest will be increased with the increase of leisure time.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.93-100
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• 2011

Maintenance of adequate soil water potential during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement within and below the rooting zone can facilitate optimal irrigation scheduling aimed at minimizing the adverse effects of water stress on crop growth and development and the leaching of water below the root zone which can have adverse environmental effects. The objective of this study was to evaluate the feasibility of using a portable irrigation controller with an Watermark sensor for the cultivation of drip-irrigated vegetable crops in a greenhouse. The control capability of the irrigation controller for a soil water potential of -20 kPa was evaluated under summer conditions by cultivating 45-day-old tomato plants grown in three differently textured soils (sandy loam, loam, and loamy sands). Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30 cm depths. Even though a repeatable cycling of soil water potential occurred for the potential treatment, the lower limit of the Watermark (about 0 kPa) obtained in this study presented a limitation of using the Watermark sensor for optimal irrigation of tomato plants where -20 kPa was used as a point for triggering irrigations. This problem might be related to the slow response time and inadequate soil-sensor interface of the Watermark sensor as compared to a porous and ceramic cup-based tensiometer with a sensitive pressure transducer. In addition, the irrigation time of 50 to 60 min at each of the irrigation operation gave a rapid drop of the potential to zero, resulting in over irrigation of tomatoes. There were differences in water content among the three different soil types under the variable rate irrigation, showing a range of water contents of 16 to 24%, 17 to 28%, and 24 to 32% for loamy sand, sandy loam, and loam soils, respectively. The greatest rate increase in water content was observed in the top of 10 cm depth of sandy loam soil within almost 60 min from the start of irrigation.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.464-472
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• 2020

We suggest a hydroponic cultivation system combined with a plasma generator to investigate the changes in the growth and functional substance content of lettuces during the cultivation period. Lettuce seedlings of uniform size were planted in semi-DFT after seeding for 3 weeks, and the plasma-activated water was intermittently operated for 1 hour at an 8 hours cycle for 4 weeks. Lettuces grew with or without plasma-activated water with the nutrient solution in hydroponics culture systems. Among the reactive oxygen species generated during plasma-activated water treatment, brown spots and necrosis appeared in the individuals closer to the plasma generating device due to O₃, and there was no significant difference in the growth parameters. While the rutin and total phenolic content of the lettuce shoot grown in the nutrient solution were higher than that of the plasma-activated water, epicatechin contents in plasma-activated water were significantly greater than the nutrient solution. However, in the roots, all kinds of secondary metabolites measured in this work, rutin, epicatechin, quercetin, and total phenolic contents, were significantly higher in the plasma-activated water than the control. These results were indicated that the growth of lettuce was decreased due to the reactive oxygen species such as ozone in the plasma-activated water, but the secondary metabolites in the root zone increased significantly. It has needed to use this technology for the cultivation of root vegetables with the modified plasma-activated water systems to increase secondary metabolite in the roots.

• Journal of the Korean Vacuum Society
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• v.17 no.3
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• pp.226-233
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• 2008

The nucleation and evolution process of Ge nano-islands on Si(001) surfaces grown by chemical vapor deposition have been explored using atomic force microscopy (AFM). The Ge nano-islands are grown by exposing the substrates to a mixture of gasses GeH4 and H2 at pressure of 0.1-0.5Torr and temperatures of $600-650^{\circ}C$. The effect of growth conditions such as temperature, Ge thickness, annealing time on the shape, size, number density, and surface distribution was investigated. For Ge deposition greater than ${\sim}5$ monolayer (ML) with a growth rate of ${\sim}0.1ML/sec$ at $600^{\circ}C$, we observed island nucleation on the surface indicating the transition from strained layer to island structure. Further deposition of Ge led to shape transition from initial pyramid and hut to dome and superdome structure. The lateral average size of the islands increased from ${\sim}20nm$ to ${\sim}310nm$ while the number density decreased from $4{\times}10^{18}$ to $5{\times}10^8cm^{-2}$ during the shape transition process. In contrast, for the samples grown at a relatively higher temperature of $650^{\circ}C$ the morphology of the islands showed that the dome shape is dominant over the pyramid shape. The further deposition of Ge led to transition from the dome to the superdome shape. The evolution of shape, size, and surface distribution is related to energy minimization of the islands and surface diffusion of Ge adatoms. In particular, we found that the initially nucleated islands did not grow through long-range interaction between whole islands on the surface but via local interaction between the neighbor islands by investigation of the inter-islands distance.

• Clinical and Experimental Pediatrics
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• v.50 no.11
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• pp.1061-1066
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• 2007

Purpose : Early identification of developmental disabilities allows intervention at the earliest possible point to improve the developmental potential. The Ages and Stages Questionnaire (ASQ), a parent- completed questionnaire, can be used as a substitute for formal screening tests. The purpose of this study was to evaluate the validity of the Korean version of the ASQ (K-ASQ) as a screening tool for detecting developmental delay of young Korean children in the setting of a busy pediatric outpatient clinic. Methods : Parents completed the K-ASQ in the waiting room of the pediatric outpatient clinic of St. Mary's Hospital, Catholic University Medical College. Out of 150 completed the ASQ, 67 who were born term and had no previous diagnosis of developmental delay, congenital anomalies, or neurological abnormalities were enrolled. The cut-off values of less than 2 standard deviations (SD) below the mean for the ASQ were used to define a "fail", and children who failed in one or more domains tested were classified as "screen-positive". Diagnosis of developmental delay was made when the developmental indices fell below -1 SD of the Bayley Scales of Infant Development-II. Results : (1) The mean age of children was $16.4{\pm}7.4$ months. Ten children (14.9%) were small-for- gestational age infants. The mean birth weight and gestational age were $3.1{\pm}0.6kg$ and $38.8{\pm}1.4$ weeks. Nine children (13.4%) were twins and 33 (49.0%) were male. The mean maternal education in years was $13.6{\pm}2.4$, and 31.3% had full-time jobs. The time for completing the ASQ was $10.2{\pm}3.0$ minutes. (2) Seventeen children (25.4%) were classified as screen-positive, four of them were delayed in development. Among eight children diagnosed with developmental delay, four were screen-positive and the other four were screen-negative by the ASQ. (3) The test characteristics of the ASQ were as follows: sensitivity (50.0%); specificity (78.0%); positive predictive value (23.5%); negative predictive value (92.0%). Conclusion : The high negative predictive value of the K-ASQ supports its use as a screening tool for developmental delay in the setting of a pediatric outpatient clinic.

• Childhood Kidney Diseases
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• v.6 no.1
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• pp.48-55
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• 2002

Purpose: Thin glomerular basement membrane nephropathy (TGBMN) is recognized as the leading cause of microscopic hematuria in both children and adults. However thinning of glomerular basement membrane (TCBM) has been found in healthy adult and also is known to be associated with various renal diseases such as Alport syndronh, IgA nephropathy and mesangial proliferative glomerulonephritis. The association of TGBM with minimal change nephrotic syndrome (MCNS) has been very rare so that the present study was undertaken to determine the relationship between TGBM and MCNS. Methods: The study population consisted of 49 children with biopsy- proven MCNS who have been admitted to the pediatric department of Kyungpook University Hospital during the past 5 years from 1997 to 2001. Group I consisted of 8 children associated with TGBM and Group II 41 children without TCBM. Various parameters such as age of illness, duration from discovery of illness to the time of biopsy, family history of hematuria and other laboratory tests were compared between these two groups and the following results were obtained. Results: Age distribution showed slightly older age in Group I ($7.1{\pm}3.5$ years) compared to Group II ($4.8{\pm}2.9$ years). However this was not statistically different (P=0.056). Family history of hematuria was noted in 2 cases in Group II. Though statistically not significant, hematuria was seen in 2 out of 8 cases ($25\%$) in MCNS children with TGBM, compared to 7 out of 41 cases ($17\%$) with MCNS children without TGBM. Other parameters such as BUN, creatinine, 24 hours urine protein excretion, serum protein, albumin, cholesterol, and T4/T8 ratio, showed no difference. Also renal biopsy finding showed no significant difference and the thickness of glomerular basement membrane in Croup I was $188{\pm}30nm$. Conclusion: TGBM was found in 8 out of 49 children with MCNS ($16.3\%$). And this high frequency of occurrence indicates that these association is not an incidental findings. Typical clinical findings of TCBMN was not noted in all of the 8 children with MCNS associated with TGBM, suggesting that thinning of glomerular basement membrane (TCBN) is secondary to rather than the cause of MCNS. (J Korean Soc Pediatr Nephrol 2002;6: 48-55)

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.4
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• pp.372-380
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• 1996

The operation of Far East Chain(GRI 5970) of Loran - C system had been stopped on June, 1995, but that of Korean Chain(GRI 9930) of Loran - C system which was jointed with North West Pacific Chain(GRI 8930) and Russia Chain(GRI 7950) by international cooperation, was started on January 1996. In this paper, in order to study the accuracy of Loran - C fix of Korean Chain, the authors examined and analyzed the data of the reciever of Loran - C(LC -90, Furuno) and GPS(AccNav Sport super (TM), Eagle) measured automatically and continually for 2 seconds at interval of 5 minutes from November 22, 1992, to January 20, 1996 at the fixed position of National Fisheries University of Pusan, The results obtained were as follows ; 1)The mean time differences of M-W, M-X, and M-Y pair measured in the base observed position were 12333.09${\mu}$s, 28338.44${\mu}$s, and 42806.01${\mu}$s respectively and the mean standard deviations of that were 0.0121${\mu}$s, 0.0290${\mu}$s, and 0.0327${\mu}$s respectively. The daily and monthly variance forms of time difference at each pair appeared in a similar reappearance. 2)The mean standard deviations of the latitude and longitude by Loran - C were 9.1m and 17.4m in W.X pair, 11.5m and 13.7m in W.Y pair, and 8.1m and 29.3m in X.Y pair respectively, and then the probable radiuses within 95% of each pair were 39.2m, 35.7m, and 60.8m, respectively. Therefore, It is to be desired that W.Y par is selected to improve the accuracy in Pusan area. 3)The mean standard deviations of the latitude and longitude by GPS were 15.4m and 15.0m and the probable radius within 95% was 43.4m. 4)The position errors for GPS and each pair of Loran - C were 16.0m to the South in GPS and 265.2m to the East in W.X pair of Loran - C, 279.5m to the North in W.Y pair of that, and 224.3m to the North-West in X.Y pair of that, so GPS is about 250m higher than Loran - C in accuracy.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.329-336
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• 2014

As an abiotic stress, chilling stress is one of the major factors limiting plant growth and increasing susceptibility to pathogens. Therefore, enhancing stress tolerance in plants is an important strategy for their survival under unfavorable environmental conditions. The objective of this study was to determine the effects of the exogenous application of salicylic acid (SA) or nitric oxide (NO) on chilling tolerance in pepper seedlings. Pepper (Capsicum annuum L. 'kidaemanbal') seedlings were grown under normal growing conditions ($20/25^{\circ}C$, 15 hours photoperiod, $145{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, fluorescence lamps) for 23 days after transplanting. The solution (3 mL) of 1 mM SA and 0.3 mM NO with surfactant triton 0.1% were sprayed two times a week, respectively. Right after the completion of chemical application, seedlings were subjected to chilling condition at $4^{\circ}C$ for 6 hours under dark condition and then the seedlings were recovered at the normal growing conditions for 2 days. In order to assess plant tolerance against chilling stress, growth characteristics, chlorophyll fluorescence (Fv/Fm), and membrane permeability were determined after chilling stress imposition. Total phenolic concentration and antioxidant capacity were measured during the whole experimental period. Disease incidence for pepper bacterial spot and wilt was also analyzed. Pepper seedlings treated with SA or NO were maintained similar dry mass ratio, while the value in control increased caused by chilling stress suggesting relatively more water loss in control plants. Electrolyte leakage of pepper seedlings treated with SA or NO was lower than that of control 2 days after chilling treatment. Fv/Fm rapidly decreased after chilling stress in control while the value of SA or NO was maintained about 0.8. SA increased higher total phenolic concentration and antioxidant capacity than NO and control during chemical treatment. In addition, increase in total phenolic concentration was observed after chilling stress in control and NO treatment. SA had an effect on the reduction of bacterial wilt in pepper seedlings. The results from this study revealed that pre-treatment with SA or NO using foliar spray was effective in chilling tolerance and the reduction of disease incidence in pepper seedlings.