• Title/Summary/Keyword: numerical analysis

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Calculation of Surface Heat Flux in the Southeastern Yellow Sea Using Ocean Buoy Data (해양부이 자료를 이용한 황해 남동부 해역 표층 열속 산출)

  • Kim, Sun-Bok;Chang, Kyung-Il
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.19 no.3
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    • pp.169-179
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    • 2014
  • Monthly mean surface heat fluxes in the southeastern Yellow Sea are calculated using directly observed airsea variables from an ocean buoy station including short- and longwave radiations, and COARE 3.0 bulk flux algorithm. The calculated monthly mean heat fluxes are then compared with previous estimates of climatological monthly mean surface heat fluxes near the buoy location. Sea surface receives heat through net shortwave radiation ($Q_i$) and loses heat as net longwave radiation ($Q_b$), sensible heat flux ($Q_h$), and latent heat flux ($Q_e$). $Q_e$ is the largest contribution to the total heat loss of about 51 %, and $Q_b$ and $Q_h$ account for 34% and 15% of the total heat loss, respectively. Net heat flux ($Q_n$) shows maximum in May ($191.4W/m^2$) when $Q_i$ shows its annual maximum, and minimum in December ($-264.9W/m^2$) when the heat loss terms show their annual minimum values. Annual mean $Q_n$ is estimated to be $1.9W/m^2$, which is negligibly small considering instrument errors (maximum of ${\pm}19.7W/m^2$). In the previous estimates, summertime incoming radiations ($Q_i$) are underestimated by about $10{\sim}40W/m^2$, and wintertime heat losses due to $Q_e$ and $Q_h$ are overestimated by about $50W/m^2$ and $30{\sim}70W/m^2$, respectively. Consequently, as compared to $Q_n$ from the present study, the amount of net heat gain during the period of net oceanic heat gain between April and August is underestimated, while the ocean's net heat loss in winter is overestimated in other studies. The difference in $Q_n$ is as large as $70{\sim}130W/m^2$ in December and January. Analysis of long-term reanalysis product (MERRA) indicates that the difference in the monthly mean heat fluxes between the present and previous studies is not due to the temporal variability of fluxes but due to inaccurate data used for the calculation of the heat fluxes. This study suggests that caution should be exercised in using the climatological monthly mean surface heat fluxes documented previously for various research and numerical modeling purposes.

Comparison Study on the Characteristics among Sasang Constitution in Acute Stroke Patients (급성기 중풍 환자의 사상체질에 따른 제특성 분포에 관한 임상적 연구)

  • Sun, Jong-Joo;Jung, Jae-Han;Choi, Chang-Min;Kim, Seok-Min;Kim, Chang-Hyun;Min, In-Gyu;Jeong, Dong-Won;Park, Sung-Uk;Jung, Woo-Sang;Moon, Sang-Kwan;Park, Jung-Mi;Ko, Chang-Nam;Cho, Ki-Ho;Kim, Young-Suk;Bae, Hyung-Sup
    • The Journal of Internal Korean Medicine
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    • v.28 no.1
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    • pp.34-46
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    • 2007
  • Objectives: This study was to assess characteristics in acute stroke patients according to Sasangconstitution (SC). Methods : We assessed the type of SC of acute stroke patients in $2^{nd}$ Department of Internal Medicine at KyungHee University Oriental Hospital from October 2005 to September 2006. Each subject's SC type was confirmed when the result of QSCC II+ was in accordance with the opinion of the Sasangconstitutional medicine specialist. We investigated general characteristics, stroke type, blood test results, alcohol drinking, smoking and dietary preferences according to SC. Results: 108 subjects were included in the final analysis. This study showed that out of the total patients, the proportion of So-yang to Tae-eum to So-eum was equal to 5.5 to 3.5 to 1. Especially, men were higher proportion So-yang while women recorded a more significant ratio of Tae-eum. Also, the BMI, waist circumference, hip circumference, and WC/HC ratio recorded significantly high results. The result indicated that even though the Tae-eum let on the highest numerical value in the aspect of their past history and the final diagnosis, no significant difference was revealed according to SC. The ratio of cerebral infarction to cerebral hemorrhage was 9 to 1. SVO, LAA, SUE are the 3 types of cerebral infarction classified by TOAST; SVO ranked the highest while SUE ranked the lowest in all constitutions. The blood test result displayed that averages of both TL and the T-chol were the highest in Tae-eum while that of hematocrit in So-yangand that of HDL-chol in So-eum. However, there was no significant difference. There were no significant differences classified by gender or by SC in the aspect of the alcohol drinking and smoking history. The majority of So-yang and Tae-eum demonstrated a preference for meat while So-eum and So-yang displayed high preferences for sea food. Conclusions : With respect to these results. we could observe the general disposition of various characteristic distributions according to SC of acute stroke patients. For further research in this field. it seems necessary to construct fundamental databases for the prevention and treatment of stroke by increasing the number of patients observed and by analyzing delicate characteristics of each constitution type.

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An Investigation of Reliability and Safety Factors in RC Flexural Members Designed by Current WSD Standard Code (현행(現行) 허용응력설계법(許容應力設計法)으로 설계(設計)되는 RC 휨부재(部材)의 신뢰성(信賴性)과 안전율(安全率) 고찰(考察))

  • Shin, Hyun Mook;Cho, Hyo Nam;Chung, Hwan Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.1 no.1
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    • pp.33-42
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    • 1981
  • Current standard code for R.C. design consists of two conventional design parts, so called WSD and USD, which are based on ACI 318-63 and 318-71 code provisions. The safety factors of our WSD and USD design criteria which are taken primarily from ACI 318-63 code are considered to be not appropriate compared to out country's design and construction practices. Furthermore, even the ACI safety factors are not determined from probabilistic study but merely from experiences and practices. This study investigates the safety level of R.C. flexural members designed by the current WSD safety provisions based on Second Moment Reliability theory, and proposes a rational but efficient way of determining the nominal safety factors and the associated flexural allowable stresses of steel bars and concretes in order to provide a consistent level of target reliability. Cornell's Mean First-Order Second Moment Method formulae by a log normal transformation of resistance and load output variables are adopted as the reliability analysis method for this study. The compressive allowable stress formulae are derived by a unique approach in which the balanced steel ratios of the resulting design are chosen to be the corresponding under-reinforced sections designed by strength design method with an optimum reinforcing ratio. The target reliability index for the safety provisions are considered to be ${\beta}=4$ that is well suited for our level of construction and design practices. From a series of numerical applications to investigate the safety and reliability of R.C. flexural members designed by current WSD code, it has been found that the design based on WSD provision results in uneconomical design because of unusual and inconsistent reliability. A rational set of reliability based safety factors and allowable stress of steel bars and concrete for flexural members is proposed by providing the appropriate target reliability ${\beta}=4$.

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Experimental study on the relaxation zone depending on the width and distance of the weak zone existing ahead of tunnel face (터널 굴진면 전방에 위치한 연약대 폭과 이격거리에 따른 이완영역에 대한 실험적 연구)

  • Ham, Hyeon Su;Lee, Sang Duk
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.5
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    • pp.855-867
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    • 2018
  • When a weak zone exists ahead of tunnel face, the stress in the adjacent area would increase due to the longitudinal arching effect and the stability of the tunnel is affected. Therefore, it is critical to prepare a countermeasure through the investigation of the frontal weakness zone of the excavated face. Although there are several researches to predict the existence of weak zone ahead of tunnel face, such as geophysical exploration, numerical analysis and tunnel support, lack of studies on the relaxation zone depending on the width or distance from the vulnerable area. In this study, the impact of the weak zone on the formation of the relaxation zone was investigated. For this purpose, a series of laboratory test were carried out varying the width of the weak zone and the separation distance between tunnel face and weak zone. In the model test, sand with a water content of 3.8% was used to form a model ground. The model weak zone was constructed with dry sand curtains. The tunnel face was adjusted to allow a sequential excavation of upper and lower half part. load cells were installed on the bottom of the foundation and the tunnel face and measuring instruments for displacement were installed on the surface of the model ground to measure the vertical stress and surface displacements due to tunnel excavation respectively. The test results show that the width of weak zone did not affect the ground settlement while the ground subsidence drastically increased within 0.25D. The vertical stress and horizontal stress increased from 0.5D or less. In addition, the longitudinal arching effect is likely within the 1.0D zone ahead of the tunnel face, which may reduce the vertical stress in the ground following tunneling direction.

A Study on the Effects of the Breath Efficiency & Lung Capacity Improvement Using Recorder Playing Focused on Breath Training (리코더 연주를 통한 뇌졸중 노력성 폐활량과 호흡 효율성 향상 연구)

  • Choi, Sung Joo
    • Journal of Music and Human Behavior
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    • v.4 no.1
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    • pp.31-46
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    • 2007
  • The purpose of the study was to improve the efficiency of Breath & Forced Vital Capacity(FVC) of Stroke Patients Using Record Playing Focused on Breath Training. The Training of Forced Vital Capacity(FVC) is focused on trunk muscles reinforce for Breathing. So the study tried to play Recorder for reinforcing FVC. The play included the two parts. One was for solo play, the other was play in concert base on solo play using Korea country song, Arirang. The Recorder play used abdominal breath, Pursed-lip & Paced methods. The course of play included Long Tone, Staccato, Crescendo, Decrescendo and throughout the course we tried to improve the efficiency & Quantity of breathe. Experiment performed at Social welfare institute for the old. They played & checked FVC, $FEV_1$, $FEV_1/FVC$ before & after breathe 19 times for 6 weeks using Spirovit SP-1, Schiller. After experiment we performed statical process(p<0.05) using statical Package software. The findings were as follows: Analysis for Experiment showed the numerical Value of increasing Of FVC, $FEV_1$, $FEV_1/FVC$. Increasing Percentage of Measured/Predicted FVC, $FEV_1$ (or calculated based on theory) ration was 25%, 13% and Quantity of FVC, $FEV_1$ 35%, 40%. Also $FEV_1/FVC$ Ratio(showed efficiency of breathe) raised 13%. And experiment data was confirmed by statical process. The experiment data was valuable under p<0.05. In Conclusion we think the results of experiment showed the efficiency of Music therapy for Breathe(FVC, $FEV_1$, $FEV_1/FVC$) reinforce.

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Analysis of Orthotropic Body under Ultimate Moment Load (극한(極限)모멘트 하중(荷重)을 받는 이방성(異方性) 구조체(構造體)의 해석(解析))

  • Chang, Suk Yoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.3
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    • pp.95-105
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    • 1985
  • This dissertation presents an exact solution for the normal and shearing stresses of an orthotropic plane body loaded by a moment load. The solution satisfies the conditions of equilibrium compatibility equations concurrently and is governing for the body being in the elasto-plastic state. An Airy stress function is introduced to solve the problem related to an orthotropic half-infinite plane under a moment load. All the equations for orthotropy must be degenerated into the expressions for isotropy when orthotropic constants are replaced by isotropic ones. The author has evaluated all the equations of orthotropy and succeeded in obtaining exactly identical expressions to the equations of isotropy which were derived independently by of L'hosptials rule. The analytical results of isotropy are compared with the simple results of other investigator. Since moment Load under the elastic state and plastic state only is a particular case of moment load under the elasto-plastic state. All the equations of elasto-plastic state case are degenerated into the expressions for the each case. The formal solution is expressed in terms of closed form. The orthotropic constants are evaluated for two kinds and two different orientations of the grain of wood and two kinds of structures. The numerical results for orthotropy are evaluated for one kind and two different orientations of three-layered ply wood. The distribution of normal and shearing stresses are shown in figures. It is noted that the distribution of stresses of orthotropic materials depends on the type of materials and orientations of the grain and stiffening.

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A Study on Shape Optimization of Plane Truss Structures (평면(平面) 트러스 구조물(構造物)의 형상최적화(形狀最適化)에 관한 구연(究研))

  • Lee, Gyu won;Byun, Keun Joo;Hwang, Hak Joo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.3
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    • pp.49-59
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    • 1985
  • Formulation of the geometric optimization for truss structures based on the elasticity theory turn out to be the nonlinear programming problem which has to deal with the Cross sectional area of the member and the coordinates of its nodes simultaneously. A few techniques have been proposed and adopted for the analysis of this nonlinear programming problem for the time being. These techniques, however, bear some limitations on truss shapes loading conditions and design criteria for the practical application to real structures. A generalized algorithm for the geometric optimization of the truss structures which can eliminate the above mentioned limitations, is developed in this study. The algorithm developed utilizes the two-phases technique. In the first phase, the cross sectional area of the truss member is optimized by transforming the nonlinear problem into SUMT, and solving SUMT utilizing the modified Newton-Raphson method. In the second phase, the geometric shape is optimized utilizing the unidirctional search technique of the Rosenbrock method which make it possible to minimize only the objective function. The algorithm developed in this study is numerically tested for several truss structures with various shapes, loading conditions and design criteria, and compared with the results of the other algorithms to examme its applicability and stability. The numerical comparisons show that the two-phases algorithm developed in this study is safely applicable to any design criteria, and the convergency rate is very fast and stable compared with other iteration methods for the geometric optimization of truss structures.

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Development of salt-tolerant transgenic chrysanthemum (Dendranthema grandiflorum) lines and bio-assay with a change of cell specificity (내염성 국화 형질전환 계통 육성 및 저항성 검정과 세포특성 변화)

  • Kang, Chan-Ho;Yun, Seung-Jung;Han, Bum-So;Lee, Gong-Joon;Choi, Kyu-Hwan;Park, Jong-Suk;Shin, Yong-Kyu
    • Journal of Plant Biotechnology
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    • v.38 no.1
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    • pp.1-8
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    • 2011
  • Recently the increasing of vinyl and green houses and development of reclaimed land including Saemangeum induced the need for breeding salt-tolerant crops which can survive and grow in high salinity soil. So we try to develop salt-tolerant transgenic chrysanthemum (Dendranthema grandiflorum.) lines by using anti-porter gene TANHX and HVNHX. Through marker selection and plant regeneration step, we could get 284 putative transgenic chrysanthemum lines. On selected putative transgenic plants, 40 candidates were used for genetic analysis and 30 lines could be made up of target size band on PCR, so about 75% of marker selected lines were decided as real transgenic lines. Selected 284 transgenic lines were also used for salt-tolerance test as a range of NaCl 0.2 ~ 1.2% (300 mM). As a result of salt-tolerance test, 15 selected transgenic lines could live and grow on the continuous supply of 0.8% (200 mM) NaCl solution and another 7 lines were could survive under 1.2% (300 mM) NaCl solution. This salt-tolerant transgenic lines under salt stress also lead a cell alternation especially a guard cell. A stressed guard cell be swelled and grow larger in proportion to NaCl concentration. TTC test for cell viability on transgenic chrysanthemum lines pointed out that more strong salt-tolerant lines can be live more than another under same salt stress. The numerical value of strong salt-tolerant 7 transgenic lines were 0.206 ~ 0.331 under 1.2% NaCl stress, and then it's value is more larger than middle salinity lines' 0.114 ~ 0.193 and non-transgenic's 0.046. And the proline contents as indicated stress compound also pointed out that HVNHX introduced salt-tolerant transgenic lines were less stressed than other under same salt stress. The contents of strong salt-tolerant transgenic lines were 2.255 ~ 2.638 mg/kg and it is much higher than that of middle salinity lines' 1.496 ~ 2.125.

Field Bioassays On Shellfish To Assess Environmental Pollution Levels Of The Masan Bay (마산만(馬山灣)의 환경오염(環境汚染) 평가(評價)를 위한 야외(野外) 생물(生物) 오염(汚染) 시험(試驗) 연구(硏究))

  • Park, Joo-Surk
    • 한국해양학회지
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    • v.14 no.1
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    • pp.15-25
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    • 1979
  • A study on field bioassay test using four species of commercially important shellfish was carried out to assess the effect of pollutants and determine the extent of marine environmental pollution of the Masan Bay from 9 to 15 August 1978. Water quality analysis and planktological examination of sea water were made during the experiment and the examination gave the following results. The water temperature was so high at 31.7$^{\circ}C$ in maximum and rather subject to change on weather condition of the land than on the effect of the water mass from outer bay. The range of DO,COD and SS at the stations were 0.3-7.08cc/l, 0.07-3.31ppm and 5.5-117ppm, respectively with the high values of COD and SS at the stations 7 and 1. The concentrations of the dissolved inorganic nitrogen in sea water, NH$\sub$4/-N, NO$\sub$2/-N, NO$\sub$3/-N, and PO$\sub$4/-P were 18.90-99.80, 2.48- 19.60, 13.00-39.00 and 1.04-14.0$\mu\textrm{g}$ at/l, respectively with decrease of their values in the outer part of the Bay. The high values mentioned above were caused by the sewage and industrial activities. The effects of organic waste are increased oxygen demand, nutrient concentration, turbidity and a higher input of pathogens, leading to structural changes in the marine ecosystems and to a considerable hazard to public health. The percentage composition of phytoplankton standing crop between diatom and dinoflagellate was characterized by making a difference between the two groups in respect of location: a decrease of diatom and a increase of dinoflagellate in numerical abundance toward inner part from outer part of the bay. Namely phytoplankton organisms were composed of 80% of diatom and 20% of dinoflagellate in outer bay, on the contrary, only 4% of diatom and 96% of dinoflagellate occupied by 94% of prorocentrum micans known as tolerant species to polluted reaas in the inner bay. On the occurrence and composition of zooplankton, there are two significant communities in the bay:one is characterized by the predominance of Oithona nana and the other by Favella sp They were composed of a range from 84% to 90% of the total organisms and monotonously constituted of themselves only at most inner station 3 even small numbers. From the results mentioned above, Oithona nana, Favella and prorocentrum micans recommed themselves as valuable indicators for judging the extent of the marine pollution.During the period of the biossays Mytilus edulis showed the highest mortality and Tapes japonica the lowest one between the four test species. The highest death rate by stations was found at most inner stations 3'and 4near Masan Free Export Zone with the most sensitive response and the lowest one occured at outer station 13 where no death specimen of oyster and arkshell was found during the whole test period.As for mussel,85 percent death rate appeared after 72 hours and 100percent rate after 120hours at station 4. It was found that the significant high mortality of the test shellfish mentioned above was caused by severe pollution with mainly organic pollutants from domestic sewage and industrial wastes from the results of too much higher concentrations of dissolved inorganic nitrogen especially ammonia-N,COD,SS and lack of dissolved oxygen,and furthermore occurrence and abundance composition of Prorcentrum,Favella and Oithona nana by stations, valuable indicator species of coastal pollution by orgnic and boilogical pollutants.

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A Method of Evaluating the Spatial Difference between Two Numerical Surfaces (두 개의 수치 평면에 대한 공간적 차이의 측정 방법)

  • Lee Jung-Eun;Sadahiro Yukio
    • Journal of the Korean Geographical Society
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    • v.41 no.2 s.113
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    • pp.212-226
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    • 2006
  • Surface data generally represent continuous distribution of geographical or social phenomena of a region in urban analysis. Instances include distribution of temperature, population of region, and various distributions related to human activities. When spatial data are given in the form of surface, surface comparison is required as a way of comprehending the surface change or the relationship between two surfaces. As for previous approaches of surface comparison, there are visualization, quantitative methods and qualitative method. All those approaches, however, show the difference between two surfaces in a limited way. Especially, they are not able to distinguish spatial difference between two surfaces. To overcome such problem, this paper proposes a method of comparing two surfaces in terms of their spatial structure. Main concept of the method comes from earth moving problem and the method is named minimum surface transformation, here. When a surface is transformed into another, total surface volume moved in the process of transformation should be the minimum. Both quantitative and spatial differences between two surfaces are evaluted by total surface volume moved and the distribution of moved surface volume of each cell respectively. The method is applied to hypothetical and actual data. From the former, it is understood that the method explains how two surfaces are quantitatively and spatially different. The result of the latter shows that moved total surface volume decreases as time goes by which fits the actual situation that population change rate gets smaller. Concerning the other measure of surface difference, the distribution of $X_{ij}$ describes detailed flow of surface volume than that of simply subtracting surface volume by indicating to what direction the population change occurs.