• Title/Summary/Keyword: Unbalanced rate

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Dietary Factors Associated with Attention Deficit Hyperactivity Disorder (ADHD) in School-aged Children (학동기 어린이 주의력결핍 과잉행동장애에서 식이요인의 역할 규명)

  • An, Minji;An, Hyojin;Hwang, Hyo-Jeong;Kwon, Ho-Jang;Ha, Mina;Hong, Yun-Chul;Hong, Soo-Jong;Oh, Se-Young
    • Korean Journal of Community Nutrition
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    • v.23 no.5
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    • pp.397-410
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    • 2018
  • Objectives: An association between dietary patterns and mental health in children has been suggested in a series of studies, yet detailed analyses of dietary patterns and their effects on ADHD (attention deficit hyperactivity disorder) are limited. Methods: We included 4569 children who had dietary intake data as part of the CHEER (Children's Health and Environmental Research) study conducted nationwide from 2005 to 2010. We assessed ADHD (Attention Deficit Hyperactivity Disorder) by the DuPaul's ADHD Rating Scales and dietary intake by a semi-quantitative food frequency questionnaire. Using intake data, we constructed five dietary patterns: "Plant foods & fish," "Sweets," "Meat & fish," "Fruits & dairy products," and "Wheat based." Results: The overall proportion of ADHD was 12.3%. Boys (17.8%) showed a higher rate of ADHD than girls (6.5%). The total intake of calories (85 kcal) and plant fat (2g) in the ADHD group was significantly higher than that of the normal group. ADHD was significantly negatively associated with dietary habits such as having breakfast and meal frequency, and positively associated with eating speed, unbalanced diet, overeating, and rice consumption. Regarding dietary patterns, the "Sweets" category was relevant to high ADHD risk (OR 1.59, 95% CI: 1.18, 2.15 for Q5 vs. Q1) in a linear relationship. An inverse, non-linear association was found between "Fruits & dairy products" and ADHD (OR 0.55, 95% CI: 0.39, 0.76 for Q4 vs. Q1). Conclusions: Our study confirms both positive and negative associations between diet and ADHD in elementary school age children. Moreover, linear or nonlinear associations between diet and ADHD draw attention to the possible threshold role of nutrients. Further studies may consider characteristics of diet in more detail to develop better intervention or management in terms of diet and health.

Joint Routing, Scheduling, and Power Control for Wireless Sensor Networks with RF Energy Transfer Considering Fairness (무선 에너지 전송 센서망에서의 공평성을 고려한 라우팅, 스케줄링, 전력 제어)

  • Moon, Seokjae;Roh, Hee-Tae;Lee, Jang-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.2
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    • pp.206-214
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    • 2016
  • Recently, radio frequency energy transfer (RFET) attracts more and more interests for powering sensor nodes in the wireless sensor network (WSN). In the conventional WSN, reducing energy consumption of sensor nodes is of primary importance. On the contrary, in the WSN with RFET, reducing energy consumption is not an important issue. However, in the WSN with RFET, the energy harvesting rate of each sensor node depends on its location, which causes the unbalanced available energy among sensor nodes. Hence, to improve the performance of the WSN with RFET, it is important to develop network protocols considering this property. In this paper, we study this issue with jointly considering routing, scheduling, and power control in the WSN with RFET. In addition, we study this issue with considering two different objectives: 'Max-min' with which we tries to maximize the performance of a sensor node having the minimum performance and 'Max-min fairness' with which we tries to achieve max-min fairness among sensor nodes. We show that our solutions can improve network performance significantly and we also discuss the differences between 'Max-min' and 'Max-min fairness'.

A Study on Management and Improvement of School Libraries with Viewpoint of Five Laws of Library Science: Focused on D Elementary School Library in Busan (도서관학 5법칙으로 본 학교도서관 운영과 개선방안 - 부산 D초등학교 도서관을 사례로 하여 -)

  • Lee, Hyeonsook;Lee, Yong-Jae
    • Journal of Korean Library and Information Science Society
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    • v.53 no.1
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    • pp.171-190
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    • 2022
  • This study aims to examine the current status of managing elementary school libraries in Busan and suggest the ways to improve it with the viewpoint of 'the five laws of library science'. The scope of study was set as the elementary school libraries in Busan, and the operation status of 304 elementary school libraries was analyzed. And for in-depth investigation, D elementary school library was examined as a case. The operation status of elementary school libraries in Busan was analyzed with the analysis elements; existence of school library, placement of teacher librarian, library collection, annual use, budget, and library seats for 6 years from 2016 to 2021. As a result, especially the placement rate of full-time teacher librarians was only 10.5%, indicating that the problem of manpower shortage was serious. As case study, the current state of managing D elementary school library was deeply investigated with perspectives of the first law and the third law of library science among Ranganathan's five laws of library science. With the first law, the investigation was divided into the aspects of open-shelf system, library location, library hours, furniture, and staff. With the third law, the investigation was done as the aspects of shelf arrangement, catalog, extended service, book selection. Especially, books with more than 50 copies for the program of reading one book each semester accounted for 4.8% of the total collection, showing the problem of unbalanced collection. As the result of this study, 'expanding the placement of teacher librarians', 'making better reading environment through remodeling', and 'balanced collection development' were suggested as the ways of developing school libraries.

The Transition of Production, Consumption and Price of Non-ferrous Metals (비철금속(非鐵金屬)의 생산(生産), 소비(消費), 시세(時勢)의 추이(推移))

  • Moon, W.J.
    • Economic and Environmental Geology
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    • v.2 no.3
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    • pp.1-25
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    • 1969
  • In considering the mining industry, it is necessary to study the production, consumption and price of ore and metals in every country of the world in order to determine the trend of the industry in the present and for the future. This study is necessary especially for exporting domestically produced are which is in excess of domestic consumption and for importing are, or metal where local production does not meet domestic demand. It will be treated of Au, Ag, Cu, Pb, Zn, W, Mo, which are the most important non-ferrous metals, and which greatly affect the mining industry of Korea. The presentation will concern itself only with the free world. About 1, 200 ton of gold are produced annually with little fluctiation in recent years. Most of the gold produced is consumed by advanced countries for industrial uses as well as for producing precious objects. The U.S.A. expends yearly about four times its domestic production and Japan about three times its domestic production for industry and arts. Because of the instability of the currency of the U.S.A., England and France, recently, the price of gold has been $ 41-42 per ounce, whereas the official price is $35.00 per ounce. It will be expected that the official price will be raised in the near future. As for silver, about 6,500 tons are produced annually with no special fluctuation change in recent years. However, the annual consumption is about 14,000 ton, so the supply and demand is extremely unbalanced. The shortage is made up by the sale of the U.S. treasury's reserve stock and the reclaiminig of silver from coins and other scrap. As the Treasury'S reserves will be exhausted in a year or two, the price of silver which is $1. 64 per ounce, will go up drastically in about a year. As for copper, 5,257,000 ton's were mined in 1966. It's production is being increased about 5% annually. However, consumption exceeds production by about 100,000 ton a year. The recent Foreign refinery copper price in the U.S.A is $ 60 per pound. The supply of copper being insufficient to meet international demands, the price will go up and with no prospect of being lowered in the near future even with the slight annual increase in production. About 2,100,000 to 2,200,000 tons of lead are produced annually. Consumption exceeds production by about 50,000-60,000 tons annually. The current price of lead in New York is $ 155 per pound. As the supply of lead is internationally stable, It will be believed that there will be no significant change in its price in the near future. In 1967, 3,926,000 tons of Zinc were produced. There is annual increase of 4-7% in production. The annual consumption exceeds production by 100,000 to 200,000 tons. The current zinc price in the St. Louis market inthe U.S.A. is $ 145 per pound. Even though its supply is stable and sufficient world wide, the consumption rate will increase at a faster pace than before; hence, the price will slowly go up. Tungsten mines yield about 11,000 tons a year. Its production has been relatively constant in the past few years. The amount of its consumption increases slowly world wide, but in the free world· there has been a slight annual decrease. However, since Red China has not been exporting their tungsten to other countries for several months, the price on the London market of S.T.U. of $Wo_3$ has increased to $ 44~46. Should Red China begin to export actively again the price will drop to $ 40~42. In 1967, 56,000 tons of Molybdenum were produced. Production exceeds consumption by 200,000 -30,000 tons annually. The current price in the U.S.A. is $ 1.72 per Mo pound. Since the rate of production in the U.S.A. is on the increase with large amounts of ore reserve, the price of molubdenum should not go up.

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Eating Habits of Children Under 4 Years with Poor-Feeding (식욕부진이 있는 4세 이하 영.유아의 식이 습관에 대한 조사)

  • Yoon, Young-Hun;Park, Yeung-Bong;Yang, Eun-Seok;Rho, Young-Ill;Kim, Eun-Young;Moon, Kyung-Rye;Lee, Chul-Gab
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.6 no.2
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    • pp.167-173
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    • 2003
  • Purpose: To find out the differences in eating habits between poor feeding and non-poor feeding children. Methods: We performed questionnaires on 504 children under four years of age who visited hospitals in Gwangju city and JaollaNamdo from May to August, 2002. Results: 138 (27.4%) children were included in poor feeding group, and 366 (72.%) children were in non-poor feeding group. Breast feeding rate was 18.8% in the poor feeding group and 20.3% in the non-poor feeding group. Duration of breast feeding for less than six months were noted in 70.5% of poor feeding group, and 58.5% of non-poor feeding group. The time at starting solid food in the poor feeding group was as follows; 15.9% of infants started on solid food when they were 2~4 months old, 32.7% during 4~6 months, 38.1% during 6~8 months and 18.8% over one year of age. Solid food was given in wrongly manners in both groups by nursing bottles, including 80.4% in poor feeding group and 66.6% in non-poor feeding group. Conclusion: This study demonstrated close relationships among poor feeding children under four years of age with history of low rate and short duration of breast feeding, inappropriate time to start on solid food, less interest in food during mealtime, and unbalanced diet. Pediatricians should make an effort to play an important role in nutritional education and treatment in children.

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The Analysis of Cost Structure and Productivity in the Korea and Japan Railroad Industry (한국과 일본 철도산업의 비용구조와 생산성 분석)

  • Park, Jin-Gyeong;Kim, Seong-Su
    • Journal of Korean Society of Transportation
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    • v.24 no.2 s.88
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    • pp.65-78
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    • 2006
  • This paper investigates the cost structure ot the Korea and Japan railroad industry with respect to density, scale and scope economies as well as productivity growth rate using a generalized trans)og multiproduct cost function model. The paper then assumes that the Korea and Japan railway companies pi·educe three outputs (incumbent railway passenger-kilometers. Shinkansen passenger-kilometers, ton-kilometers of freight) using four input factors (labor, fuel, maintenance, rolling stock and capital). The specified cost function includes foul other independent variables: track lengths to reflect network effects, two dummies to reflect nation and ownership effects, and time trend as a proxy for technical change. The simultaneous equation system consisting of a cost function and three input share equations is estimated with the Zellner's iterative seemingly unrelated regression. The unbalanced panel data used in the paper, a total of 154 observations. are collected from the annual records of the Korea National Railroad (KNR) for the yews $1977{\sim}2003$, Japan National Railways (JNR) for the years $1977{\sim}1984$. seven Japan Railways (JR's) for the years $1987{\sim}2003$. The findings show that the Korean and Japanese railways exhibit product-specific and overall economies of density but product-specific diseconomies of scale with respect to incumbent railway passenger-kilometers, Shinkansen-kilometers and ton-kilometers. However, the railways experience mild overall economies of scale which result from economies of scope associated with the joint production of incumbent railway/Shinkansen and feight, freight/incumbent railway and Shinkansen except Shinkansen/incumbent railway and freight. In addition, the economies of density and scale in the KNR, JR east, JR central, and JR west companies at the point of the years $1990{\sim}2003$ average is generally analogous to the above results at the point of sample average. There also appear to be economies of ssope associated with the joint Production of the incumbent railway and Shinkansen in JR central but diseconomies of scope in JR East and JR West. The findings also indicate that the productivity growth rate of the privately-owned JR's is larger than that of the government-owned KNR.

Properties in Strength of Raschel Netting (랏쉘그물감의 강도)

  • KIM Dai An
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.11 no.1
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    • pp.39-48
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    • 1978
  • 1) The decrease in strength of Raschel twines at Raschel joints is regarded to be due mainly to the frictional force between yarns and the unbalanced tensile distribution by the deformation of the joints. The rate of the decrease is about $13\%$ in lengthwise pull and 22 to $26\%$ in breadthwise pull. 2) The 3-course joint is less in deformation and stronger than the 2-course joint in all cases of pulls. 3) The variation of Raschel joint strength $T_R$ with the angle $\varphi$ between the adjacent bars is expressed as $T_R=T_{R0}-k\varphi$ where $T_{R0}$ is the strength at $\varphi=0^{\circ}$ and K is a constant. 4) The tensile strength ${\sigma}R$ and tile breaking energy $E_R$ of Raschel netting are given by $${\sigma}R=KN\;or\;${\sigma}R=T_RN$$ and $$E_R=AN$$ respectively, where N is the number of meshes at the pulling side, and K and A are constants. But the breaking energy of the netting is almost constant independent of tile variation of N. 5) The Raschel netting with some bars cut already breaks from tile joints of the bars next to the cut bars and its tensile strength, breaking energy, and breaking elongation decrease largily even if only one bar is in already cut state. 6) The tearing strength of Raschel netting is almost equal to the tensile strength of its single joint pulled by two bars. 7) The twisted joint is much more excellent in strength than the knot or the Raschel joint. The knot strength is 69 to $76\%$, and the Raschel joint strength is 71 to $74\%$ in lengthwise pull and 62 to $67\%$ in breadthwise pull, respectively, of the twisted joint strength.

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A Study on Eating Habits of Elementary School Students and the Perception on the Nutrition Education in Curriculum (초등학생의 식습관 실태 및 학교 교육과정에서의 영양교육에 대한 인식)

  • Lee Ji Eun;Jung In-Kyung
    • Journal of Korean Home Economics Education Association
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    • v.17 no.2
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    • pp.79-93
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    • 2005
  • The purpose of this was to present the efficient directions of nutrition education for elementary school children. We examined the problems of eating habits. nutrition knowledge, and perception and expectations on nutrition education of elementary school children in school. This study was carried out using a self-administered questionnaire and subjects were 562 elementary school children in Gyeonggi Province. All data in this research was analyzed through SAS program, and the frequency$(\%)$ and the $mean{\pm}S.D.$ on each question were calculated. Data for each group was analyzed according to sex and the difference among the groups were treated for significance by using chi-square test and Student t-test. About $87.6\%$ of the children have a meal over three times a day, and $76.7\%$ answered that they ate at a certain time regularly everyday. Only $69.6\%$ of subjects said that they ate breakfast everyday, showing very high levels of skipping breakfast. The most common frequency of eating snacks was 'once a day' in both sexes(male $52.2\%$, female $48.6\%$). In the perception on the eating habits, $69.3\%$ of children recognized problems on dieting habits, such as unbalanced diet. irregular eating time, and overeating. The perceived and correct knowledge of nutrition were $99.5\%$ and $86.9\%$, respectively. Most of the children$(99.1\%)$ acknowledged that nutrition education need to be carried out in school. And children want to deeply deal with 'cooking', 'growth and nutrition', 'good eating habits', 'nutrition and disease', These results indicated that elementary school children tended to have undesirable eating behaviors, but the rate of children who recognize the importance and the needs of nutrition education in school was high. Therefore, their parents and teachers need to perform continuous education through a curriculum and life instruction so that students have healthy habits by considering what the problems of nutrition habits are, as the elementary students considerably recognize problems of their own dietary habits and needs of nutrition education.

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Analyzing the Efficiency of Korean Rail Transit Properties using Data Envelopment Analysis (자료포락분석기법을 이용한 도시철도 운영기관의 효율성 분석)

  • 김민정;김성수
    • Journal of Korean Society of Transportation
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    • v.21 no.4
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    • pp.113-132
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    • 2003
  • Using nonradial data envelopment analysis(DEA) under assumptions of strong disposability and variable returns scale, this paper annually estimates productive. technical and allocative efficiencies of three publicly-owned rail transit properties which are different in terms of organizational type: Seoul Subway Corporation(SSC, local public corporation), the Seoul Metropolitan Electrified Railways sector (SMESRS) of Korea National Railroad(the national railway operator controlled by the Ministry of Construction and Transportation(MOCT)), and Busan Urban Transit Authority (BUTA, the national authority controlled by MOCT). Using the estimation results of Tobit regression analysis. the paper next computes their true productive, true technical and true allocative efficiencies, which reflect only the impacts of internal factors such as production activity by removing the impacts of external factors such as an organizational type and a track utilization rate. And the paper also computes an organizational efficiency and annually gross efficiencies for each property. The paper then conceptualized that the property produces a single output(car-kilometers) using four inputs(labor, electricity, car & maintenance and track) and uses unbalanced panel data consisted of annual observations on SSC, SMESRS and BUTA. The results obtained from DEA show that, on an average, SSC is the most efficient property on the productive and allocative sides, while SMESRS is the most technically-efficient one. On the other hand. BUTA is the most efficient one on the truly-productive and allocative sides, while SMESRS on the truly-technical side. Another important result is that the differences in true efficiency estimates among the three properties are considerably smaller than those in efficiency estimates. Besides. the most cost-efficient organizational type appears to be a local public corporation represented by SSC, which is also the most grossly-efficient property. These results suggest that a measure to sort out the impacts of external factors on the efficiency of rail transit properties is required to assess fairly it, and that a measure to restructure (establish) an existing(a new) rail transit property into a local public corporation(or authority) is required to improve its cost efficiency.

A Study on the Characteristics of Dietary Behaviors and Food Intake Patterns of University Student according to the Obesity Index (대학생의 비만도에 따른 식생활 특성 및 식이섭취 양상에 관한 연구)

  • Oh Se-In;Lee Mee-Sook
    • The Korean Journal of Food And Nutrition
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    • v.19 no.1
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    • pp.79-90
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    • 2006
  • This study was performed to investigate the dietary behaviors and food intake patterns of university students according to the obesity index(OI). The subjects were 349 students(107 males and 242 females) who were assigned to one of the following groups based on the percentage of ideal body weight: underweight(OI< 90%), normal ($90%{\leq}Ol<10%$) and overweight($OI{\geq}110%$). The dietary behaviors and food intake patterns were evaluated by questionnaires and 24 hour recall method. The results were summarized as follows. The rates of underweight, normal, and overweight students were 33.8%, 61.0%, and 5.2% respectively. The ratios of underweight was higher than overweight, especially in case of female. The 60.46% of subjects responded that they had an irregular eating habits, especially in overweight group(72.22%). The 52.44% of subjects showed skipping mealtime more than one time per day. The overweight group had a tendency to overeat themselves than other groups. The normal group had less unbalanced dietary pattern than the other groups(p<0.0019). Most subjects had a snack(96.27%). The percentage of those who drank and smoked were 86.74% and 19.54%, respectively. The smoking value was significantly higher in the overweight group(p<0.0009). The food consumption frequency by food groups was not different among the groups except instant and fast food. More than 50% subjects consumed fish, legumes & its products, and vegetables everyday. There was significantly less rate of the instant and fast food consumption frequency in the normal group(p<0.0177). The 3/4 subjects that showed the lower consumed level in RDA(< 75%) were under-nutritional state in the Fe and Ca. In case of Ca, there was a higher NAR value in the overweight group(p<0.0257) significantly, and Fe, protein, vitamin $B_1$, vitamin $B_2$, and niacin showed similar tendencies. The INQ of Fe was significantly higher in the overweight group than other groups(p<0.0335).