• Title/Summary/Keyword: Plank problem

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PLANK PROBLEMS, POLARIZATION AND CHEBYSHEV CONSTANTS

  • Revesz, Szilard-Gy.;Sarantopoulos, Yannis
    • Journal of the Korean Mathematical Society
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    • v.41 no.1
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    • pp.157-174
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    • 2004
  • In this work we discuss "plank problems" for complex Banach spaces and in particular for the classical $L^{p}(\mu)$ spaces. In the case $1\;{\leq}\;p\;{\leq}\;2$ we obtain optimal results and for finite dimensional complex Banach spaces, in a special case, we have improved an early result by K. Ball [3]. By using these results, in some cases we are able to find best possible lower bounds for the norms of homogeneous polynomials which are products of linear forms. In particular, we give an estimate in the case of a real Hilbert space which seems to be a difficult problem. We have also obtained some results on the so-called n-th (linear) polarization constant of a Banach space which is an isometric property of the space. Finally, known polynomial inequalities have been derived as simple consequences of various results related to plank problems.

An Analysis of Heating and Cooling Energy Cost according to Building Type of Apartment Complex (공동주택 단지의 주동형식에 따른 냉난방 에너지 비용 분석)

  • Roh, Ji-Woon
    • Journal of the Korean Solar Energy Society
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    • v.33 no.1
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    • pp.96-105
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    • 2013
  • This study aims to investigate the energy performance of apartment in respect of complex design, building type and generation house layout and finally to produce the guide line for energy saving design. To grasp the present condition and problem about this subject, apartment building types were examined and representative types were extracted. Considering azimuth angle, private area, and generation number, building type of the subject apartment was classified in detail, energy simulation was conducted, and the effect to energy cost was compared. In the research, using VE energy simulation program, the heating and cooling load were calculated and converted to energy cost. It is expected that this analysed results will be basic data for the more integrated study. Research consequence can be summarized as follow: 1) Energy cost is compared according to several azimuth in plank '一' type apartment. As the results, calculated gas cost is the best in $49^{\circ}$, but total cost is in $-31^{\circ}$. 2) Apartment buildings of tower types are compared, it is resulted that 'Y' type (azimuth $-7^{\circ}$, $-20^{\circ}$) is the best in gas cost, but the total cost is worst because of high cooling load.

A Study of 'Mode Selecting Stochastic Controller' for a Dynamic System Under Random Vibration

  • Kim Yong-Kwan;Lee Jong-Bok;Heo Hoon
    • Journal of Mechanical Science and Technology
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    • v.19 no.10
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    • pp.1846-1855
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    • 2005
  • This paper presents a new stochastic controller applied on the vibration control system under irregular disturbances based on the mode selection scheme. Measured displacement and frequency characteristics are simultaneously used in designing a mode selecting controller. This technique is validated by applying to the suppression problem of a flexible beam with randomly vibrated circumstances. The presented method, called Mode Selecting Stochastic Controller, uses the frequency measurement of the flexible system based on a Fast-Fourier transformation algorithm. This controller is constructed by combining mode selection method with previous known Stochastic Controller in real time: Numerical simulations and several experiments are conducted to validate the proposed method. The performance of the proposed method is compared with a stochastic controller developed recently. This method was improved compared with previous one.

An Analysis of Heating and Cooling Energy and Effect on Outdoor Air Cooling according to Building Type of Apartment Complex (공동주택 단지의 주동형식에 따른 냉난방 에너지 및 외기냉방 효과 분석)

  • Roh, Ji-Woong
    • Journal of the Korean Solar Energy Society
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    • v.34 no.4
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    • pp.31-38
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    • 2014
  • This study makes three apartment building complex an object of analyzing representative building types and energy consumption rate of house holds, and effect of outdoor air cooling. Recently created apatrment complex is composed of very various types of building, plan, and orientation etc. But, it is difficult to remark conclusively that these various types of buildings are designed energy-effectively. Because architects are hard to find useful energy design guideline for decision making. By the preceding study, the present condition and problem about this subject is grasped, apartment building types were examined and representative types were extracted. In this study, energy simulation was conducted, and the effect to outdoor air cooling was analyzed about representative types of the subject apartment complex. It is expected that this analysed results will be basic data for the more integrated study. Research consequence can be summarized as follow: 1) Besides solar gain, household layout of building, orientation, and plan etc. effects compositively on energy consumption rate. 2) The effect of ourdoor air cooling in building of tower type can be improved by arranging households appropriately.

A Study on the Definition of Panok in the Records of the Joseon Dynasty - Based on the Records Related to DB Pan-ock in Institute for the Translation of Korean Classics - (조선 시대 기록을 통해서 본 판옥의 정의에 관한 연구 - 한국고전종합DB의 판옥(板屋) 관련 기록을 중심으로 -)

  • Kim, Ra-Nee;Han, Dong-Soo
    • Journal of the Korean Institute of Rural Architecture
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    • v.24 no.4
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    • pp.117-124
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    • 2022
  • Recognizing the problem that the definition of the term pan-ock does not appear precisely in the dictionary, the definition of pan-ock was established through analysis by analyzing 183 cases of pan-ock searched in the Korean Classics DB and classifying them into buildings and ships. First of all, the 65 pan-ocks classified as architecture were used in various ways, such as residences, religious facilities, jang-pan-ocks, and prisons, depending on their use. Second, the 90 cases of pan-ock related to ships were the concept of houses that combine work and accommodation on ships. Finally, through military installations, literary expressions, and bureaucrats who have seen trains and wagons, Pan-ock uses boards. It can be used for walls or roofs only, or for both walls and roofs. Therefore, it is necessary to consider the case of the Joseon Dynasty with the definition of Pan-ock in the existing dictionary. In other words, Pan-ock refers to "houses, religious facilities, royal tombs, and prisons, with various uses and forms. In addition, it refers to the joining of only the wall or the roof with planks, or the joining of both the wall and the roof," suggesting a broader interpretation of the category.

Explicit Nonlinear Finite Element Analysis for Flexural/Shear Behavior of Perfobond FRP-Concrete Composite Beam (퍼포본드 FRP-콘크리트 합성보의 휨/전단거동에 관한 외연적 비선형 유한요소해석 연구)

  • Yoo, Seung-Woon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.771-776
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    • 2020
  • In this study, the flexural/shear behavior characteristics of perfobond FRP-concrete composite beams using an FRP plate with perforated webs as formwork and reinforcement are analyzed through an analytical method. Compared with the existing experimental results, we have proved its usefulness and use it in future practice. When the nonlinearity is very large in this case, the nonlinear finite element analysis by an explicit method will be effective. The concrete damage plasticity (CDP) model adopted in this study is considered to be able to adequately simulate the nonlinear behavior of concrete, and the determination of several variable factors required in the model is compared with the experimental results and values used in the study. This recommendation will require review and adjustment for more diverse cases. The effect of the perfobond of the composite beam with perforated web is considered to be somewhat effective in terms of securing the initial stiffness, but in the case of the apex, it is considered that the cross-sectional loss and the effect of improving the bonding force should be properly arranged. The contact problem, such as slipping of the FRP plate and concrete, is considered to be one of the reasons that the initial stiffness is slightly larger than the test result, and the slightly difference from the experimental results is attributed to the separation problem between concrete and FRP after the peak.

A Study on the Nutritive Value and Utilization of Powdered Seaweeds (해조의 식용분말화에 관한 연구)

  • Yu, Jong-Yull;Lee, Ki-Yull;Kim, Sook-Hee
    • Journal of Nutrition and Health
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    • v.8 no.1
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    • pp.15-37
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    • 1975
  • I. Subject of the study A study on the nutritive value and utilization of powdered seaweeds. II. Purpose and Importance of the study A. In Korea the shortage of food will be inevitable by the rapidly growing population. It will be very important study to develop a new food from the seaweeds which were not used hitherto for human consumption. B. The several kinds of seaweeds have been used by man in Korea mainly as side-dishes. However, a properly powdered seaweed will enable itself to be a good supplement or mixture to certain cereal flours. C. By adding the powdered seaweed to any cereals which have long been staple foods in this country the two fold benefits; saving of cereals and change of dietary pattern, will be secured. III. Objects and scope of the study A. Objects of the study The objects will come under four items. 1. To develop a powdered seaweed as a new food from the seaweeds which have been not used for human consumption. 2. To evaluate the nutritional quality of the products the analysis for chemical composition and animal feeding experiment will be conducted. 3. Experimental cocking and accepability test will be conducted for the powdered products to evaluate the value as food stuff. 4. Sanitary test and also economical analysis will be conducted for the powdered products. B. Scope of the study 1. Production of seaweed powders Sargassum fulvellum growing in eastern coast and Sargassum patens C.A. in southern coast were used as the material for the powders. These algae, which have been not used for human consumption, were pulverized through the processes of washing, drying, pulverization, etc. 2. Nutritional experiments a. Chemical composition Proximate components (water, protein, fat, cellulose, sugar, ash, salt), minerals (calcium, phosphorus, iron, iodine), vitamins (A, $B_1,\;B_2$ niacin, C) and amino acids were analyzed for the seaweed powders. b. Animal feeding experiment Weaning 160 rats (80 male and 80 female rats) were used as experimental animals, dividing them into 16 groups, 10 rats each group. Each group was fed for 12 weeks on cereal diet (Wheat flour, rice powder, barley powder, potato powder, corn flour) with the supplementary levels of 5%, 10%, 15%, 20% and 30% of the seaweed powder. After the feeding the growth, feed efficiency ratio, protain efficiency ratio and ,organs weights were checked and urine analysis, feces analysis and serum analysis were also conducted. 3. Experimental cooking and acceptability test a. Several basic studies were conducted to find the characteristics of the seaweed powder. b. 17 kinds of Korean dishes and 9 kinds of foreign dishes were prepared with cereal flours (wheat, rice, barley, potato, corn) with the supplementary levels of 5%, 10%, 15%, 20% and 30% of the seaweed powder. c. Acceptability test for the dishes was conducted according to plank's Form. 4. Sanitary test The heavy metals (Cd, Pb, As, Hg) in the seaweed powders were determined. 5. Economical analysis The retail price of the seaweed powder was compared with those of other cereals in the market. And also economical analysis was made from the nutritional point of view, calculating the body weight gained in grams per unit price of each feeding diet. IV. Results of the study and the suggestion for application A. Chemical composition 1. There is no any big difference in proximate components between powders of Sargassum fulvellum in eastern coast and Sargassum patens C.A. in southern coast. Seasonal difference is also not significant. Higher levels of protein, cellulose, ash and salt were found in the powders compared with common cereal foods. 2. The levels of calcium (Ca) and iron (Fe) in the powders were significantly higher than common cereal foods and also rich in iodine (I). Existence of vitamin A and vitamin C in the Powders is different point from cereal foods. Vitamin $B_1\;and\;B_2$ are also relatively rich in the powders.'Vitamin A in ·Sargassum fulvellum is high and the levels of some minerals and vitamins are seemed4 to be some influenced by seasons. 3. In the amino acid composition methionine, isoleucine, Iysine and valine are limiting amino acids. The protein qualities of Sargassum fulvellum and Sargassum patens C.A. are seemed to be .almost same and generally ·good. Seasonal difference in amino acid composition was found. B. Animal feeding experiment 1. The best growth was found at.10% supplemental level of the seaweed Powder and lower growth rate was shown at 30% level. 2. It was shown that 15% supplemental level of the Seaweed powder seems to fulfil, to some extent the mineral requirement of the animals. 3. No any changes were found in organs development except that, in kidney, there found decreasing in weight by increasing the supplemental level of the seaweed powder. 4. There is no any significant changes in nitrogen retention, serum cholesterol, serum calcium and urinary calcium in each supplemental level of the seaweed powder. 5. In animal feeding experiment it was concluded that $5%{\sim}15%$ levels supplementation of the seaweed powder are possible. C. Experimental cooking and acceptability test 1. The seaweed powder showed to be utilized more excellently in foreign cookings than in Korean cookings. Higher supplemental level of seaweed was passible in foreign cookings. 2. Hae-Jo-Kang and Jeon-Byung were more excellent than Song-Pyun, wheat cake, Soo-Je-Bee and wheat noodle. Hae-Je-Kang was excellent in its quality even as high as 5% supplemental level. 3. The higher levels of supplementation were used the more sticky cooking products were obtained. Song-Pyun and wheat cake were palatable and lustrous in 2% supplementation level. 4. In drop cookie the higher levels of supplementation, the more crisp product was obtained, compared with other cookies. 5. Corn cake, thin rice gruel, rice gruel and potato Jeon-Byung were more excellent in their quality than potato Man-Doo and potato noodle. Corn cake, thin rice gruel and rice gruel were excellent even as high as 5% supplementation level. 6. In several cooking Porducts some seaweed-oder was perceived in case of 3% or more levels of supplementation. This may be much diminished by the use of proper condiments. D. Sanitary test It seems that there is no any heavy metals (Cd, Pb, As, Hg) problem in these seaweed Powders in case these Powders are used as supplements to any cereal flours E. Economical analysis The price of the seaweed powder is lower than those of other cereals and that may be more lowered when mass production of the seaweed powder is made in future. The supplement of the seaweed powder to any cereals is also economical with the criterion of animal growth rate. F. It is recommended that these seaweed powders should be developed and used as supplement to any cereal flours or used as other food material. By doing so, both saving of cereals and improvement of individual's nutrition will greatly be achieved. It is also recommended that the feeding experiment for men would be conducted in future.

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