• International journal of advanced smart convergence
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• 제12권3호
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• pp.233-243
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• 2023

In modern society, since the expansion of the e-commerce market and the spread of the pandemic, face-to-face business are gradually changing to non-face-to-face. In the logistics industry, the demand for unmanned courier storage is increasing due to lack of loading space from urbanization and courier theft accidents. As the demand for unmanned parcel lockers increases, improved functions such as food storage and efficient space loading are required. This study develops an integrated model-based evaluation procedure of product based on performance factors according to the IEC 61508 standard for newly unmanned parcel storage devices with active loading technology, and derive Critical Technology Element based on the product's core functions and performance goals. As proposing these research, We expect improve the safety and reliability of development targets by identifying and evaluating elements.

• 한국지진공학회논문집
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• 제23권2호
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• pp.131-140
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• 2019

Diagonally reinforced concrete coupling beams (DRCBs) have been widely adopted in reinforced concrete (RC) bearing wall systems. DRCBs are known to act as a fuse element dissipating most of seismic energies imparted to the bearing wall systems during earthquakes. Despite such importance of DRCBs, the damage estimation of such components and the corresponding consequences within the knowledge of performance based seismic design framework is not well understood. In this paper, drift-based fragility functions are developed for in-plane loaded DRCBs. Fragility functions are developed to predict the damage and to decide the repair method required for DRCBs subjected to earthquake loading. Thirty-seven experimental results are collected from seventeen published literatures for this effort. Drift-based fragility functions are developed for four damage states of DRCBs subjected to cyclic and monotonic loading associated with minor cracking, severe cracking, onset of strength loss, and significant strength loss. Damage states are defined in a consistent manner. Cumulative distribution functions are fit to the empirical data and evaluated using standard statistical methods.

• 산업기술연구
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• 제21권B호
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• pp.163-174
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• 2001

A dynamic reliability model for analyzing the stability of armor units on rubble-mound breakwater is mathematically developed by using Hudson's formula and definition of single-failure mode. The probability density functions of resistance and loading functions are defined properly, the related parameters to those probability density functions are also estimated straightforwardly by the first-order analysis. It is found that probabilities of failure for the stability of armor units on rubble-mound breakwater are continuously increased as the service periods are elapsed, because of the occurrence of repeated loading of random magnitude by which the resistance may be deteriorated. In particular, the factor of safety is incorporated into the dynamic reliability model in order to evaluate the probability of failure as a function of factor of safety. It may thus be possible to take some informations for optimal design as well as managements and repairs of armor units on rubble-mound breakwater from the dynamic reliability analyses.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권5호
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• pp.279-285
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• 2003

Lidocaine and galactose loading tests were performed on a bioartificial liver (BAL), an extracorporeal medical device incorporating living hepatocytes in a cartridge without a transport barrier across the membranes. The concentration changes were analyzed using pharmacokinetic equations to evaluate the efficacy and limitation of the proposed method. Lidocaine and galactose were found to be suitable drugs for a quantitative evaluation of the BAL functions, as they did not interact with the plasma proteins or blood vessels, making their concentrations easy to determine. The drug concentration changes after drug loading were easily analyzed using pharmacokinetic equations, and the BAL functions quantitatively expressed by pharmacokinetic parameters, such as the clearance (CL) and galactose elimination capacity (GEC). In addition, these two drugs have already been used in clinical tests to evaluate human liver functions over long periods, and lidocaine CL values and GEC values reported for a normal human liver. Thus, a comparison of the CL and GEC values for the BAL and a natural liver revealed what proportion of normal liver functions could be replaced by the BAL.

• Industrial Engineering and Management Systems
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• 제3권1호
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• pp.22-37
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• 2004

An integrated heuristic approach based on genetic algorithms (GAs) is proposed for solving the container selection and loading problems. The GA for container selection solves a two-dimensional knapsack problem, determining a set of containers to minimize the transportation or shipment cost. The GA for container loading solves for the weighted coefficients in the evaluation functions that are applied in selecting loading positions and boxes to be loaded, so that the volume utilization is maximized. Several loading constraints such as box orientation, stack priority, stack stability, and container stability are also incorporated into the algorithm. In general, our computational results based on randomly generated data and problems from the literature suggest that the proposed heuristic provides a good solution in a reasonable amount of computational time.

• Journal of Biosystems Engineering
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• 제20권1호
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• pp.87-94
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• 1995

When farmer loads and unloads farm products with a trailer, linked to a tractor, the tractor-trailer is backed up to the loading duck. However, travelling backward is not easy and takes a time for even skilled operators. Therefore, unmanned backing up is necessary to save the effort. A backward controller of tractor-trailer was simulated using fuzzy logic and genetic algorithms. Operators drive the tractor-trailer back and forth several times for backing up to the loading duck. As the operators did it, a backward controller was designed using fuzzy logic. And genetic algorithms was applied to improve the performance of the backward controller. With the strings coded with the fuzzy membership functions, genetic operations were carried out. After 30 generations, the best fitted fuzzy membership functions were found. Those membership functions were used in the fuzzy backward controller. The fuzzy controller combined with genetic algorithms showed the better results than the fuzzy controller did alone.

• 한국항공우주학회지
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• 제31권8호
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• pp.91-98
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• 2003

발사체의 구조해석적인 측면에서 외부하중에 따른 발사체의 반응을 파악하는 것은 중요한 일이다. 기본적으로 발사체는 응력집중이나 내부 모듈간의 변위 간섭 등이 일어나지 않게 설계되어야한다. 이를 위해서는 외부하중에 관한 연구가 선행되어야 한다. 발사체에 작용하는 외부하중 중 연소 및 배기에 의해 발생하는 음향하중은 통계적 방법으로 다루어야 하는 랜덤 하중이다. 본 연구에서는 발사시 작용하는 음향하중에 대하여 하중 함수를 구성하고, 이를 이용하여 발사체의 하중해석을 수행하였다. 음원 할당 방법으로 음향하중을 추정하여 하중함수를 구성하였고, 이를 발사체의 유한요소 모델에 적용하였다. 응력해석을 이용하여 발사체의 구조 강성을 확인할 수 있었으며, 발사체 각 섹션의 경계면에서의 가속도 파워 스펙트럴 밀도함수를 구할 수 있었다. 이러한 결과를 이용하여 각 섹션의 진동 시험에 필요한 스펙을 도출할 수 있다.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 International Conference on Digital Policy & Management
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• pp.375-387
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• 2004

The paper presents an Integrated E-Community System (IECS) for management, decision and service, designed for the e-government project of Haishu District of Ningbo, Zhejiang, China. The project need is to promote the integration of management information and service information of communities, providing a unified platform on which different departments of the district government can share and exchange community information, government officers can analyze information and make decisions, and the outside users can access and request services. To meet the project need, the IECS consists of five parts: 1) The Central DataBase (CDB) that stores all information related with management, decision and service of communities: 2) Information Extracting Subsystem (IES) that provides functions of extracting data from data sources, transforming and loading them into the CDB for system administrators; 3) Information Management Subsystem (IMS) that provides functions of querying and sharing of information for government users, and functions of information maintenance, rights and log management for system administrators: 4) Intelligent Analysis Subsystem (IAS) that provides functions of extracting analysis related data from the CDB and loading them into the DW, and functions of multi-dimensional analysis and decision-making based on the DW and OLAP for government users; 5) Information Service Website (ISW) that provides functions of promulgating and collecting of information for government users and system administrators, and functions of browsing, querying and requesting of service information for outside users. The IECS supports management, decision and service of a government based on a unified data platform--the CDB, and ensures data security by providing different workplaces and rights for different users. In the real application, the system works well.

• Interaction and multiscale mechanics
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• 제1권3호
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• pp.317-328
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• 2008

When carbon-filled rubber specimens are subjected to cyclic loading, they do not return to their initial state after loading and subsequent unloading, but exhibit a residual strain or permanent deformation. We propose a specific form of the pseudo-elastic energy function to represent cyclic loading for incompressible, isotropic materials with stress softening and residual strain. The essence of the pseudo-elasticity theory is that material behaviour in the primary loading path is described by a common elastic strain energy function, and in unloading, reloading or secondary unloading paths by a different strain energy function. The switch between strain energy functions is controlled by the incorporation of a damage variable into the strain energy function. An extra term is added to describe the permanent deformation. The finite element implementation of the proposed model is presented in this paper. All parameters in the proposed model and elastic law can be easily estimated based on experimental data. The numerical analyses show that the results are in good agreement with experimental data.

• 품질경영학회지
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• 제20권2호
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• pp.129-136
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• 1992

This paper aims to develope an algorithm to minimize the total production time, sum of group formation times and processing times, under the balanced workload among the machines by grouping parts with machine loading in FMS. The algorithm of this study is composed of four step procedures ; (1) Parts grouping by Group Technology(GT) (2) Minimizing total processing time in loading problem (3) Machine workload balancing, including above(2) (4) Group formation time, including above(3) For parts grouping, Rank Order Clustering(ROC) algorithm developed by King(1980) is used and this algorithm is programmed by using the MACRO functions of QUATTRO Pro, one of the spreadsheet packages. The structure for loading model is solved by using the Hyper-LINDO. As a case study, numerical examples are demonstrated to show the effectiveness of the proposed machine loading procedure.