• Title/Summary/Keyword: limit theory

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Development of Optimal Train Operation System in Bottle-neck Section According to the Opening of High Speed Railway in Seoul Metropolitan Area (수도권 고속철도개통에 따른 고속선 병목구간 최적열차운행 체계 연구)

  • Chun, Chunggeun;Chung, Sungbong;NamKung, Baekkyu
    • Journal of the Korean Society for Railway
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    • v.15 no.6
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    • pp.631-637
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    • 2012
  • New Opening of Suseo-Pyeongteak High Speed Railway (HSR) will be a new leap in the Korean railway history. However if this section of HSR line around Seoul Metropolitan Area opens, the confluence of new HSR and existing HSR line in Pyeongteak-Osong section will cause a bottle neck problem. In other words, the opening of Suseo-Pyeongteak HSR line will make the capacity of track reach the limit and the section of railroad between Pyeongteak and Osong will be saturated. This will also make such troubles as restricting the number of train which stops at Cheonan-Asan station. In this study, based on the train assignment theory of TVM430 signal system, the methods of calculating headway and number of train are reviewed and the plan for application of optimal operation pattern during peak hour between Pyeongteak-Osong section is also suggested. To remove the bottle neck problem in this HSR section, 3 alternatives are suggested and the expected effects and problems of each alternative are also analyzed. The results show that the troubles caused by excess of track capacity can be removed without any additional cost if the minimum headway in operating system for HSR is adopted in this section. In the future, if these alternatives are considered to the long-term plan for operating train and signal systems, this will improve the efficiency of train operation, which can remove the bottle neck in the HSR line.

Nurturing Experience of Mothers of Children with Disabilities Admitted to a Group-Home (장애아동을 그룹홈에 입소시킨 어머니의 양육경험)

  • Hwang, Yeon-Hwa;Im, Jong-Ho
    • The Journal of the Korea Contents Association
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    • v.16 no.8
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    • pp.257-267
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    • 2016
  • The research subject is 8 mothers who put their physical/mentally impaired children in a group home, as the research method, this study conducted an in-depth interview survey. The participants of this study collected data from the in-depth interview on 8 mothers who put their disabled children to the group home. In the result of open coding, total 34 concepts, 28 subcategories and 13 categories were derived. The core category in the selective coding was 'establishing restorative relationship through entering a group home after encountering the limit of nurture.' Practical Strategies include the following; first, it's necessary to provide psychology counselling consequent on a mother's nurturing phase, and this study proposes a program for a father having a child with disability; in addition, there is the necessity of having to arrange the differentiated facility for physically/mentally impaired people, which meets the needs of the relevant people. At a level of policy, this study suggested the necessity of having to take into account the minimization of poverty problem facing a family having a disable child through the caring card, necessity of the use of good-natured card, and medical-social-welfare-based intervention, expansion of facility-touring class installation, and use of adult guardianship system, and differential payment of disabled child nurturing allowance consequent on income quantile, etc.

Resistance Factor and Target Reliability Index Calculation of Static Design Methods for Driven Steel Pipe Pile in Gwangyang (광양지역에 적합한 항타강관말뚝의 목표신뢰성지수 및 저항계수 산정)

  • Kim, Hyeon-Tae;Kim, Daehyeon;Lim, Jae-Choon;Park, Kyung-Ho;Lee, Ik-Hyo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8128-8139
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    • 2015
  • Recently, the necessity of developing the load and resistance factor design(LRFD) for soft ground improvement method has been raised, since the limit state design is requested as international technical standard for the foundation of structures. In this study, to develop LRFD codes for foundation structures in Korea, target reliability index and resistance factor for static bearing capacity of driven steel pipe piles were calibrated in the framework of reliability theory. The 16 data(in Gwangyang) and the 57 data(Korea Institute of Construction Technology, 2008) sets of static load test and soil property tests conducted in the whole domestic area were collected along with available subsurface investigation results. The resistance bias factors were evaluated for the tow static design methods by comparing the representative measured bearing capacities with the expected design values. Reliability analysis was performed by two types of advanced methods : the First Order Reliability Method (FORM), and the Monte Carlo Simulation (MCS) method using resistance bias factor statistics. As a result, when target reliability indices of the driven pipe pile were selected as 2.0, 2.33, 2.5, resistance factor of two design methods for SPT N at pile tip less than 50 were evaluated as 0.611~0.684, 0.537~0.821 respectively, and STP N at pile tip more than 50 were evaluated as 0.545~0.608, 0.643~0.749 respectively. The result from this research will be useful for developing various foundations and soil structures under LRFD.

The prosthetic approach and principle for an collapsed VDO ; A clinical case of pseudo Class III patient (저위교합환자의 보철적 접근법과 이론 : Pseudo Class III 교합환자 증례)

  • Kwon, Kung-Rock;Choi, Dae-Gyun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.20 no.2
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    • pp.121-134
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    • 2004
  • This article describes a clinical protocol for the conventional rehabilitation of patient diagnosed with partial anodontia. A combined dental therapy approach was used and included endodontic therapy and root capping on the maxillary central incisors, fabrication of a maxillary overdenture, and fabrication of mandibular konus overdenture supported by 3 konus abutments. Within this protocol, tooth-supported overdenture prostheses are used for 2 purposes: first, to obtain the most rigid retention and function at an established maxillary-mandibular relationship; and second, to continuously maintain function and esthetic appearance applying immediate dentures after teeth extraction. The idea behind this protocol and its associated clinical procedures is presented along with a discussion compared with implant therapy. In the case introduced, and after 7 years of observation, the therapy can be seen as a success. We increased the occlusal vertical height in this case, but it would be more appropriate to see this as recovering the occlusal vertical height that was lost. The process of increasing the occlusal vertical height, that is restoration of the face, modification of the extrinsic occlusion of the incisors, and retraction of the mandible is very difficult and important. Ultimately, class III malocclusion is fixed, adequate occlusal vertical height is gained, and the retracted posterior anodontial portion is restored by prosthodontic dentures based on the rigid support theory. The result of the therapy done on the later-achieved malocclusion with partial anodontia on the posterior portion must consider the following in order to maintain the safety of the esthetics of the tooth and face for a period of time: 1) occlusal restoration with an ideal occlusal vertical height, 2) allowance of the final occlusion induced by the functional relationship of the upper and lower jaw, 3)final occlusion functionally induced by the lip competence limit.

Dynamic Prefetch Filtering Schemes to enhance Utilization of Data Cache (데이타 캐시의 활용도를 높이는 동적 선인출 필터링 기법)

  • Chon, Young-Suk;Kim, Suk-Il;Jeon, Joong-Nam
    • Journal of KIISE:Computer Systems and Theory
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    • v.35 no.1
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    • pp.30-43
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    • 2008
  • Memory reference instructions such as loads or stores are critical factors that limit the processing power of processor. The prefetching technique is an effective way to reduce the latency caused from memory access. However, excessively aggressive prefetch leads to cache pollution so as to cancel out the advantage of prefetch. In this study, four filtering schemes have been compared and evaluated which dynamically decide whether to begin prefetch after referring a filtering table to decrease cache pollution. First, A bi-states scheme has been shown to analyze the lock problem of the conventional scheme, this scheme such as conventional scheme used to be N:1 mapping, but it has the two state to 1bit value of each entries. A complete state scheme has been introduced to be used as a reference for the comparative study. A block address lookup scheme has been proposed as the main idea of this paper which exhibits the most exact filtering performance. This scheme has a length of the table the same as the bi-states scheme, the contents of each entry have the fields the same as the complete state scheme recently, never referenced data block address has been 1:1 mapping a entry of the filter table. Experimental results from commonly used general benchmarks and multimedia programs show that average cache miss ratio have been decreased by 10.5% for the block address lookup scheme(BAL) compare to conventional dynamic filter scheme(2-bitSC).

Design and Implementation of a Backup System for Object based Storage Systems (객체기반 저장시스템을 위한 백업시스템 설계 및 구현)

  • Yun, Jong-Hyeon;Lee, Seok-Jae;Jang, Su-Min;Yoo, Jae-Soo;Kim, Hong-Yeon;Kim, Jun
    • Journal of KIISE:Computer Systems and Theory
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    • v.35 no.1
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    • pp.1-17
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    • 2008
  • Recently, the object based storage devices systems(OSDs) have been actively researched. They are different from existing block based storage systems(BSDs) in terms of the storage unit. The storage unit of the OSDs is an object that includes the access methods, the attributes of data, the security information, and so on. The object has no size limit and no influence on the internal storage structures. Therefore, the OSDs improve the I/O throughput and the scalability. But the backup systems for the OSDs still use the existing backup techniques for the BSDs. As a result, they need much backup time and do not utilize the characteristics of the OSDs. In this paper, we design and implement a new object based backup system that utilizes the features of the OSDs. Our backup system significantly improves the backup time over existing backup systems because the raw objects are directly transferred to the backup devices in our system. It also restores the backup data much faster than the existing systems when system failures occur. In addition, it supports various types of backup and restore requests.

A Study of the Designing and Producing of Efficient Stage Costume Using Rented Costume - Focusing on the Western Clothes used in the Performance "Lee Jin" - (대여의상을 이용한 효율적인 무대의상 디자인 및 제작에 관한 연구 - 공연<리진>에 사용된 서양복을 중심으로 -)

  • Kim, Young-Sam;Woo, Bo-Kyung;Han, Na-Ra;Yin, Xiang-Lan
    • Journal of the Korean Society of Costume
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    • v.59 no.3
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    • pp.157-165
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    • 2009
  • This study intends to discuss the efficient stage costume design that uses costume-rentals and production method as a realistic alternative for production of stage costume of low budget performance. Directly participating in the costume design and production of the performance , this researcher applied the methodology of corroborative study on the basis of production process and results by referring to the papers and literature published by academic society for the theory necessary for study. Centering around the western costume in the stage costumes of , the scope of study was the costume of Paris, France prevalent at the end of the 19th century which is epochal background of performance. In spite of its merit of reducing production charge and production in the low budget performance, costume-rentals is subject to the lack of considering unitγ with other visual factors and limit in reflecting the creativity of costume designer. The following actions shall be taken to solve such problem. First, it is essential to set production direction and plan that meets budget and work concept. Second, it is required to highlight the characteristic factor of the age which is the background of work so as to grant the sense of age and to produce the visual unity of costume by supplementing the costume composition. Third, it is necessary to make large effect with low lost by using costume articles that can express the characteristics of the age. Fourth, it is required to efficiently reflect the transformation of design by minimizing the damage of costume through research on the sewing method and materials as well as creative idea. In this way, the efficient stage costume could be realized in the performance with low budget by approaching costume-rentals in the viewpoint of costume design, transforming it in accordance with work concept and adding the visual factors.

Ultimate Strength of branch-rotated T-joints in Cold-formed Square Hollow Sections-Chord web failure mode- (지관이 회전된 냉간성형 각형강관 T형 접합부의 최대내력(II)-주관 웨브 파괴모드-)

  • Bae, Kyu Woong;Park, Keum Sung;Kang, Chang Hoon;Moon, Tae Sup
    • Journal of Korean Society of Steel Construction
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    • v.15 no.1
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    • pp.69-76
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    • 2003
  • This paper described the ultimate strength and deformation limit of new uniplanar T-joints in cold-formed square hollow sections. The new T-joint had the configuration that only a branch member was oriented at 45 degrees to a chord member in the plane of the truss. This study focused on the branch-rotated T-joints governed by chord web failure. Based on the test results of the T-joint in cold-formed square hollow sections, the deformation lirnit was found to be 3%B for $16.7{\leq}2(B/T){\leq}33.3$ and $0.63{\leq}(b_1/B)=0.7$. Existing strength formulas for traditional T-joint were investigated, and the new strength formula for the branch-rotated T-joint was proposed. This proposed formula was based on column buckling theory considering the rounded corners of cold-formed square hollow sections. Finally, the optimization condition of yield stress and $2{\gamma}$ was recommended to select the optimized chord section.

Research on the Leadership Types in Italian Restaurants (이태리 레스토랑 종사자들의 리더십 유형에 관한 연구)

  • Yim, Seoung-Bean;Kim, Pan-Jin
    • Journal of Distribution Science
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    • v.10 no.12
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    • pp.35-43
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    • 2012
  • Purpose - This study analyzes the effects of types of leadership on the employees of Italian restaurants, its efficacy, and organizational citizenship behavior, utilizing a causal assessment model. In this study, independent variables such as the type of leadership perceived in the manager or chef by an Italian restaurant's employees, and its efficacy were parameters, and the organizational citizenship behavior and organizational effectiveness were the variables representing the results in the hypothesis. The study aimed to draw implications by verifying the leadership via efficacy and the impact on organizational citizenship behavior of Italian restaurants. Research design, data, methodology - For the purpose of this analysis, specific questionnaire items were configured according to the theory and efficacy of the study. From a questionnaire used in organizational citizenship behavior comprising 22 questions, six were modified to suit the research purpose of this study. The configured questionnaire comprised 5 parts and 40 items. A Likert (Likert) 5-point scale was utilized to measure responses to the questionnaire items from the employees of an Italian restaurant in Seoul who participated in the survey. For data collection, 400 questionnaires were distributed, and 344 collected. Factor analysis and reliability verification were conducted using SPSS18.0 and AMOS18.0. A covariance structure analysis was conducted to test the research hypotheses. Results - Based on the results of the analyses, the summary and suggested implications of the research are as follows: The covariance structure analysis used to analyze the kind of effect transformational and transactional leadership styles in Italian restaurant employees had on self-efficacy, group-efficacy, and organizational citizenship behavior, indicated that among the characteristics of transformational leadership (such as, idealized influence, inspirational motivation, individual consideration, and intellectual stimulation), idealized influence and individual consideration had a positive influence on self-efficacy. Idealized influence, individual consideration, conditional reward, and management by exception also positively influenced self-efficacy and altruistic and conscientious behavior (organizational citizenship behavior). Conclusions - Results suggest that with regard to self-efficacy and group efficacy, managers in different departments and chefs should provide team members with a vision for the future, increase their confidence in their abilities, and build their trust in the organization. By evaluating employee performance and experiences, management can demonstrate leadership and encourage organizational citizenship behavior through enjoyable, voluntary participation. Transformational and transactional leadership is effective in group processes that include social-exchange relationships, self-efficacy and group efficacy, and organizational citizenship behavior. However, as this research study utilizes only self-reported data, it has several limitations, such as a vulnerability of errors caused by the various experiment types. A significant limitation of this study is the lack of potential for the duplication of results. The covariance structure analysis, however, provides complementation to limit the impact of errors from self-reporting studies. A future study can extend this research by utilizing different data collection methods.

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Theory of efficient array observations of microtremors with special reference to the SPAC method (SPAC 방법에 근거한 상시진동의 효과적 배열 관측 이론)

  • Okada, Hiroshi
    • Geophysics and Geophysical Exploration
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    • v.9 no.1
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    • pp.73-85
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    • 2006
  • Array observations of the vertical component of microtremors are frequently conducted to estimate a subsurface layered-earth structure on the assumption that microtremors consist predominantly of the fundamental mode Rayleigh waves. As a useful tool in the data collection, processing and analysis, the spatial autocorrelation (SPAC) method is widely used, which in practice requires a circle array consisting of M circumferential stations and one centre station (called "M-station circle array", where M is the number of stations). The present paper considers the minimum number of stations required for a circle array for efficient data collection in terms of analytical efficacy and field effort. This study first rearranges the theoretical background of the SPAC algorithm, in which the SPAC coefficient for a circle array with M infinite is solely expressed as the Bessel function, $J_0(rk)$ (r is the radius and k the wavenumber). Secondly, the SPAC coefficient including error terms independent of the microtremor energy field for an M-station circle array is analytically derived within a constraint for the wave direction across the array, and is numerically evaluated in respect of these error terms. The main results of the evaluation are: 1) that the 3-station circle array when compared with other 4-, 5-, and 9-station arrays is the most efficient and favourable for observation of microtremors if the SPAC coefficients are used up to a frequency at which the coefficient takes the first minimum value, and 2) that the Nyquist wavenumber is the most influential factor that determines the upper limit of the frequency range up to which the valid SPAC coefficient can be estimated.