• Title/Summary/Keyword: Reasonable alternative

Search Result 315, Processing Time 0.026 seconds

A partial factors methodology for structural safety assessment in non-linear analysis

  • Castro, Paula M.R.P.;Delgado, Raimundo M.;Cesar de Sa, Jose M.A.
    • Computers and Concrete
    • /
    • v.2 no.1
    • /
    • pp.31-53
    • /
    • 2005
  • In the present structural codes the safety verification is based on a linear analysis of the structure and the satisfaction of ultimate and serviceability limit states, using a semi-probabilistic security format through the consideration of partial safety factors, which affect the action values and the characteristic values of the material properties. In this context, if a non-linear structural analysis is wanted a difficulty arises, because the global safety coefficient, which could be obtained in a straightforward way from the non-linear analysis, is not directly relatable to the different safety coefficient values usually used for the different materials, as is the case for reinforced concrete structures. The work here presented aims to overcome this difficulty by proposing a methodology that generalises the format of safety verification based on partial safety factors, well established in structural codes within the scope of linear analysis, for cases where non-linear analysis is needed. The methodology preserves the principal assumptions made in the codes as well as a reasonable simplicity in its use, including a realistic definition of the material properties and the structural behaviour, and it is based on the evaluation of a global safety coefficient. Some examples are presented aiming to clarify and synthesise all the options that were taken in the application of the proposed methodology, namely how to transpose the force distributions obtained with a non-linear analysis into design force distributions. One of the most important features of the proposed methodology, the ability for comparing the simplified procedures for second order effects evaluation prescribed in the structural codes, is also presented in a simple and systematic way. The potential of the methodology for the development and assessment of alternative and more accurate procedures to those already established in codes of practice, where non-linear effects must be considered, is also indicated.

A Study on the Socio-economic Characteristics of the Angler Population and the Estimation of A Fishing Frequency Function (유어낚시인구의 사회경제학적 특성과 출조빈도함수의 추정에 관한 연구)

  • Park Cheol-Hyung
    • The Journal of Fisheries Business Administration
    • /
    • v.36 no.1 s.67
    • /
    • pp.81-101
    • /
    • 2005
  • This article is to estimate the fishing frequency function in Korean recreational fishery with respect to socio-economic characteristics of anglers. First, the study described the characteristics of the entire angler population on the view points of 9 socio-economic variables. And then, the study divided the total angler population into three groups of in-land, sea, and mixed angler populations in order to investigate the differences in their characteristics. The study could confirm the existence of differences in regions, size of regions, and educational levels between the in - land and the sea angler populations by testing heterogeneity in the frequency table. The fishing frequency function is estimated using Poisson regression model in order to accomodate the count data(non-negative discrete random variable) aspects of the fishing frequency. However, the model specification error is found due to overdispersion of data. The model exhibits the lack of goodness of fit. The negative binomial regression model is adopted to cure the overdispersion of the data as an alternative estimation methodology. Finally, the study can confirm overdispersion does not exist in the model any more and the goodness of fit improved significantly to the reasonable level. The results of estimation of fishing frequency population modeled by the negative binomial regression models are following. The three variables of region, sex, and education have effects on the decision making process of fishing frequency in the case of in-land recreation fishery. On the other hand, the three variables of sex, age, and marriage status do the same job in the case of sea angler population. Among the left-over variables, both income and use of Internet variables now affect on the process in mixed angler population. Finally, the results of whole angler population show that all of the previous variables are proven to be statistically significant due to the summation of data with all three sub-groups of angler population.

  • PDF

Bioequivalence Approaches for Highly Variable Drugs: Issue and Solution (개체 변이가 큰 약물 (highly variable drug)의 생물학적동등성 시험을 위한 실험설계 및 평가방법)

  • Baek, In-Hwan;Seong, Soo-Hyeon;Kwon, Kwang-Il
    • Korean Journal of Clinical Pharmacy
    • /
    • v.19 no.1
    • /
    • pp.50-60
    • /
    • 2009
  • Highly variable drugs (within-subject variability greater than 30%) have been difficult to meet current regulatory acceptance criteria using a reasonable number of study subjects. In this study, we reviewed previous studies presenting alternative approaches for bioequivalence evaluation of highly variable drugs, and focused on an approach for widening the bioequivalence acceptance limits using within-subject variability. We discussed the suggested five solutions for highly variable drug including the deletion of $C_{max}$ of the bioequivalence criteria, direct expansion of bioequivalence limit, multiple dose studies in steady state, bioequivalence assessment on the metabolite, add-on study, and widening the bioequivalence acceptance limits based on reference variability. The methods for widening of bioequivalence limits based on reference variability are scaled average bioequivalence containing within-subject variability on reference drug (${\sigma}_{WR}$), population bioequivalence derived from total variability on reference drug (${\sigma}_{TR}$) and test drug (${\sigma}_{TT}$), and individual bioequivalence derived from subject by formulation interaction variability (${\sigma}_D$) and within subject variability on reference drug (${\sigma}_{WR}$) and test drug (${\sigma}_{TR}$). To apply these methods, the switching variability (${\sigma}_0$) will have to be set by the regulatory authorities. The proposals of bioequivalence evaluation approach for the highly variable in Korea are presented for both of new drug and reevaluation drug.

  • PDF

Methods for improving efficiency in Apartment Maintenance Management using on Analytic Hierarchy Process (AHP 기법을 이용한 공동주택 유지관리 효율성 제고 방안)

  • Lee, Jeong-Bok
    • Korean Journal of Construction Engineering and Management
    • /
    • v.7 no.4 s.32
    • /
    • pp.69-77
    • /
    • 2006
  • In recent years, there has been more reconstruction and redevelopment of apartments rather than efforts to consider alternative to extend the life time of the apartments. It is essential to try to develop ways to adequately maintain and to use the apartment facilities efficiently in order to preserve earth environment and the limited resource. However, tacking research on the effects obtained through remodelling and maintenance have interfered with the vitalizing of the market. The objective of this study is to propose criterions and methods with which to evaluate adequacy of maintenance management. A survey was performed to investigate important maintenance methods in order to obtain advices that can smoothly progress improve apartment maintenance management. This study applied AHP(Analytical Hierarchy Process) methods for reasonable maintenance in apartment. Through this study, the flow of apartment maintenance market is elevated to reaching the level in advanced nation.

A Survey on the Barrier-Free Environment of Public Office Building in Jeju Area (제주지역 공공업무시설의 장애물 없는 생활환경 실태조사 연구)

  • Seong, Ki-Chang;Park, Chul-Min;Kim, In-Bae
    • Journal of The Korea Institute of Healthcare Architecture
    • /
    • v.22 no.4
    • /
    • pp.29-36
    • /
    • 2016
  • Purpose: Considering the proportion of the population such as the elderly, pregnant women, infants companion and constantly increasing foreign tourists, there is a high need for implementing an environment without barriers. In terms of policy and institutional aspects, Jeju Special Self-Governing Province is striving to create an environment without barriers and to promote the safety and convenience of Vulnerable Pedestrians. But it is not enough to create a viable barrier-free environment. Methods: Method of this research is to analyze the general population status and installed facilities status for the disabled in Jeju. And analysis of policy research needs and level of barrier-free. By applying the barrier-free environment certification standards should conduct an assessment of the level of the current public office buildings in Jeju. It presents the environmental improvement of public office buildings for barrier-free environment. Result: Barrier-free environment status of the five public office buildings research surveyed all buildings have shown low levels of installed facilities for the disabled. In particular, it was analyzed that represents a very low level in the intermediate facilities and other facilities. The development of a specific installation manual for the facilities for the disabled is required to improve public office buildings. And barrier-free criteria need to reflect on the implementation of regulations. Implications: Through continuous research to analyze the barrier-free level and problems of public office buildings, it will be made to improve the comprehensive and reasonable alternative.

Design and Implementation of iATA-based RAID5 Distributed Storage Servers (iATA 기반의 RAID5 분산 스토리지 서버의 설계 및 구현)

  • Ong, Ivy;Lim, Hyo-Taek
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.14 no.2
    • /
    • pp.305-311
    • /
    • 2010
  • iATA (Internet Advanced Technology Attachment) is a block-level protocol developed to transfer ATA commands over TCP/IP network, as an alternative network storage solution to address insufficient storage problem in mobile devices. This paper employs RAID5 distributed storage servers concept into iATA, in which the idea behind is to combine several machines with relatively inexpensive disk drives into a server array that works as a single virtual storage device, thus increasing the reliability and speed of operations. In the case of one machine failed, the server array will not destroy immediately but able to function in a degradation mode. Meanwhile, information can be easily recovered by using boolean exclusive OR (XOR) logical function with the bit information on the remaining machines. We perform I/O measurement and benchmark tool result indicates that additional fault tolerance feature does not delay read/write operations with reasonable file size ranged in 4KB-2MB, yet higher data integrity objective is achieved.

Development of the Interconnection Evaluation System for Dispersed Generations in Distribution Systems (분산전원의 배전계통 연계 평가 시스템의 개발에 관한 연구)

  • Kang Min-Kwan;Park Jae-Ho;Oh Yong-Taek;Hong Sang-Eun;Rho Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.7 no.1
    • /
    • pp.12-20
    • /
    • 2006
  • Recently, new dispersed sources (DSG) such as Photovoltaic, Wind Power, fuel cell etc. are interconnected with distribution systems as national projects for alternative energy preparing for oil crisis. This paper deals with the optimal evaluation algorithms in the case where new dispersed sources are operated in distribution systems. It is very difficult and complicated to handle the interconnection issues for proper voltage managements, because professional skills and enormous amounts of data for the evaluations are required. The typical evaluation algorithms mainly depending on individual ability and quality of data acquired, inevitably cause the different results f3r the same issue, so unfair and subjective evaluations are unavoidable. In order to overcome these problems, this paper proposes reasonable and general algorithms based on the standard model system and proper criterion, which offers the fair and objective evaluations in any case.

  • PDF

A Study on Receipt Caused by Spatial Transformation of Kitchen Space in Apartment Housing

  • Choi, Lee-Seoung;Kim, Hyung-Woo
    • Journal of the Korea Furniture Society
    • /
    • v.19 no.4
    • /
    • pp.260-272
    • /
    • 2008
  • The recent concept of kitchen is likely defined as "Kitchen Culture" including the function of living room where all families make a conversation as well as a dinner, and it is becoming another type of the residential environment, deviating from the stereotype as only cooking area. Particularly the comfortableness of living room is closely associated with a receipt function of kitchen, and the sort & dimension & size of furniture and diversity of shapes playa more meaningful role for improving our life standard & comfortableness compared with the past, nevertheless this receipt study is carelessly handled in the first phase of construction. This Study is focusing on understanding the modern concept of kitchen where the open space concept is being introduced as more reasonable space concept, and on suggesting a solution for receipt-function of the modern kitchen concept connected with "L-D-K (Living room - Dining room- Kitchen)" space idea. In the Chapter 2 the concept of receipt and function of kitchen, the wide variety of kitchen utensils was checked up, and in the Chapter 3 the change of trends of kitchen area & receipt space was considered, and finally in the Chapter 4 the modern concept of kitchen was presented, by instancing overseas examples with receipt planning. As a consequence, the alternative of the receipt in the modern kitchen is to install an Ireland table or another type of receipt-available table (lower furniture) in the dead space between kitchen & living room for motivating smooth communication and convenient receipt, and that is the trend nowadays. Kitchen desires a rapid change. Through this kind of study it should be more researched that kitchen is not an independent space any more and lies in the mutual connection of L-D-K.

  • PDF

Development and Application of Pre/Post-processor to EMTP for Sequence Impedance Analysis of Underground Transmission Cables (지중 송전선로 대칭분 임피던스 해석을 위한 EMTP 전후처리기 개발과 활용)

  • Choi, Jong-Kee;Jang, Byung-Tae;An, Yong-Ho;Choi, Sang-Kyu;Lee, Myoung-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.63 no.10
    • /
    • pp.1364-1370
    • /
    • 2014
  • Power system fault analysis has been based on symmetrical component method, which describes power system elements by positive, negative and zero sequence impedance. Obtaining accurate line impedances as possible are very important for estimating fault current magnitude and setting distance relay accurately. Especially, accurate calculation of zero sequence impedance is important because most of transmission line faults are line-to-ground faults, not balanced three-phase fault. Since KEPCO has started measuring of transmission line impedance at 2005, it has been revealed that the measured and calculated line impedances are well agreed within reasonable accuracy. In case of underground transmission lines, however, large discrepancies in zero sequence impedance were observed occasionally. Since zero sequence impedance is an important input data for distance relay to locate faulted point correctly, it is urgently required to analyze, detect and consider countermeasures to the source of these discrepancies. In this paper, development of pre/post processor to ATP (Alternative Transient Program) version of EMTP (Electro-Magnetic Transient Program) for sequence impedance calculation was described. With the developed processor ATP-cable, effects of ground resistance and ECC (Earth Continuity Conductor) on sequence impedance were analyzed.

X11ARIMA Procedure (한국형 X11ARIMA 프로시져에 관한 연구)

  • 박유성;최현희
    • The Korean Journal of Applied Statistics
    • /
    • v.11 no.2
    • /
    • pp.335-350
    • /
    • 1998
  • X11ARIMA is established on the basis of X11 which is one of smoothing approach in time series area and this procedure was introduced by Bureau of Census of United States and developed by Dagum(1975). This procedure had been updated and adjusted by Dagum(1988) with 174 economic index of North America and has been used until nowadays. Recently, X12ARIMA procedure has been studied by William Bell et.al. (1995) and Chen. & Findly(1995) whose approaches adapt adjusting outliers, Trend-change effects, seasonal effect, arid Calender effect. However, both of these procedures were implemented for correct adjusting the economic index of North America. This article starts with providing some appropriate and effective ARIMA model for 102 indexes produced by national statistical office in Korea; which consists of production(21), shipping(27), stock(27), and operating rate index(21). And a reasonable smoothing method will be proposed to reflect the specificity of Korean economy using several moving average model. In addition, Sulnal(lunar happy new year) and Chusuk effects will be extracted from the indexes above and both of effects reflect contribution of lunar calender effect. Finally, we will discuss an alternative way to estimate holiday effect which is similar to X12ARIMA procedure in concept of using both of ARIMA model and Regression model for the best fitness.

  • PDF