• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.6
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• pp.3046-3070
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• 2017

Nowadays, the utilization of multiprocessor environments has been increased due to the increase in time complexity of application programs and decrease in hardware costs. In such architectures during the compilation step, each program is decomposed into the smaller and maybe dependent segments so-called tasks. Precedence constraints, required execution times of the tasks, and communication costs among them are modeled using a directed acyclic graph (DAG) named task-graph. All the tasks in the task-graph must be assigned to a predefined number of processors in such a way that the precedence constraints are preserved, and the program's completion time is minimized, and this is an NP-hard problem from the time-complexity point of view. The results obtained by different approaches are dominated by two major factors; first, which order of tasks should be selected (sequence subproblem), and second, how the selected sequence should be assigned to the processors (assigning subproblem). In this paper, a hybrid proposed approach has been presented, in which two different artificial ant colonies cooperate to solve the multiprocessor task-scheduling problem; one colony to tackle the sequence subproblem, and another to cope with assigning subproblem. The utilization of background knowledge about the problem (different priority measurements of the tasks) has made the proposed approach very robust and efficient. 125 different task-graphs with various shape parameters such as size, communication-to-computation ratio and parallelism have been utilized for a comprehensive evaluation of the proposed approach, and the results show its superiority versus the other conventional methods from the performance point of view.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.13
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• pp.515-536
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• 2000

This study analyzes the U.S. case law which challenges the legal conclusions of the district court with respect to the applicability, and effect, of the doctrine of waiver and estoppel in addition to the doctrine of documentary cure. The impliations are as follows. First, the documentary cure requirement can not be interpreted to mean early enough to allow the beneficiary to cure and represent the documents before the presentment deadline or expiry date of letter of credit. The mere fact that the presentment period expired before the completion of bank's review and notification process does not compel any conclusion about whether the examiner spent a reasonable amount of time examining the documents. Indeed, the reasonable time requirement does not imply that banks examine a presentation out of order or hurry a decision based upon particular needs or desires of a beneficiary. Secondly, even if the doctrine of waiver can apply to letter of credit governed by the strict compliance standard, a one-time acceptance of discrepant documents by a bank does not waive the bank's right to insist upon conforming documents in all subsequent letter of credit transactions between the bank and beneficiary. Revised UCC Article 5 is highly persuasive on this point: waiver of discrepancies by issuer or an applicant in one or more presentation does not waive similar discrepancies in a future presentation. Neither the issuer nor the beneficiary can reasonably rely upon honor over past waivers as a basis for concluding that a future defective presentation will justify honor.

• Journal of Adhesion and Interface
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• v.17 no.1
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• pp.21-28
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• 2016

Foam-type biodegradable polyurethane adhesives were developed as a non-lethal weapon against illegal fishing boats. The adhesives were prepared from a hardener of polymeric methylene diphenyl diisocyanate (MDI) and a base composed of polyester and/or polyether polyols. In order to accelerate biodegradability, starch, dextrin, and amylase were added into the base, and which present about 34% degradability within 4 weeks confirmed by OECD 301C method. For proper mixing and corresponding prompt foam reaction, viscosities of hardener and base compositions were investigated in the temperature ranges from 0 to $50^{\circ}C$. For fast completion of the foam forming and corresponding adhesion, rising time was recorded in the same temperature range, and the rising time of the adhesive was varied within around 1 minute. T-peel adhesion tests with cotton fabrics were performed which showed 20.78 N/cm and 11.95 N/cm as the maximum and the average values, respectively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.64-71
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• 2015

In this paper, we present a multi-period 0-1 knapsack problem which has the cardinality constraints. Theoretically, the presented problem can be regarded as an extension of the multi-period 0-1 knapsack problem. In the multi-period 0-1 knapsack problem, there are n jobs to be performed during m periods. Each job has the execution time and its completion gives profit. All the n jobs are partitioned into m periods, and the jobs belong to i-th period may be performed not later than in the i-th period, i = 1, ${\cdots}$, m. The total production time for periods from 1 to i is given by $b_i$ for each i = 1, ${\cdots}$, m, and the objective is to maximize the total profit. In the extended problem, we can select a specified number of jobs from each of periods associated with the corresponding cardinality constraints. As the extended problem is NP-hard, the branch and bound method is preferable to solve it, and therefore it is important to have efficient procedures for solving its linear programming relaxed problem. So we intensively explore the LP relaxed problem and suggest a polynomial time algorithm. We first decompose the LP relaxed problem into m subproblems associated with each cardinality constraints. Then we identify some new properties based on the parametric analysis. Finally by exploiting the special structure of the LP relaxed problem, we develop an efficient algorithm for the LP relaxed problem. The developed algorithm has a worst case computational complexity of order max[$O(n^2logn)$, $O(mn^2)$] where m is the number of periods and n is the total number of jobs. We illustrate a numerical example.

• Journal of the Ergonomics Society of Korea
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• v.33 no.3
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• pp.241-253
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• 2014

Objective: The objective of this study was to examine multi-modal interaction effects of input-mode switching on the use of smart phones. Background: Multi-modal is considered as an efficient alternative for input and output of information in mobile environments. However, there are various limitations in current mobile UI (User Interface) system that overlooks the transition between different modes or the usability of a combination of multi modal uses. Method: A pre-survey determined five representative tasks from smart phone tasks by their functions. The first experiment involved the use of a uni-mode for five single tasks; the second experiment involved the use of a multi-mode for three dual tasks. The dependent variables were user preference and task completion time. The independent variable in the first experiment was the type of modes (i.e., Touch, Pen, or Voice) while the variable in the second experiment was the type of tasks (i.e., internet searching, subway map, memo, gallery, and application store). Results: In the first experiment, there was no difference between the uses of pen and touch devices. However, a specific mode type was preferred depending on the functional characteristics of the tasks. In the second experiment, analysis of results showed that user preference depended on the order and combination of modes. Even with the transition of modes, users preferred the use of multi-modes including voice. Conclusion: The order of combination of modes may affect the usability of multi-modes. Therefore, when designing a multi-modal system, the fact that there are frequent transitions between various mobile contents in different modes should be properly considered. Application: It may be utilized as a user-centered design guideline for mobile multi modal UI system.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.5
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• pp.16-28
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• 2007

In this study, the implications for landscape architecture in the restoration Project of Cheonggyecheon will be shown through the analysis of factors for landscape architect scheme modification. The method of study consists of theoretical study, analysis of the plan and design of landscape architecture of the restoration project of Cheonggyecheon, and deduction of implications thereof. The controversial feints included the many difficulties in realizing the productive design of landscape architecture due to the selective collecting of public opinion and the problems of settling the complications, the design limit of the turnkey and MA systems, the lack of hydraulic knowledge and technology and the shortage of vegetation monitoring data and experimental materials. The alternative proposals are as follows: 1) there should be agreement between the government organization and the civil group, 2) in the turnkey bidding for the river restoration projects, the river restoration design based on the volume divided into some parts should be reconsidered in order to maintain consistency in the total design, 3) in order to maintain consistency in the planning policies, MA designs should also be introduced and applied from the first stage of the project through its completion, and 4) data such as the safe water level in case of flooding for the facilities and the vegetation and data in connection with the ecological restoration of river should be accumulated. If these controversies are not settled effectively, the river restoration project will be delayed due to complications with the citizens and wasted time and effort will result from the frequent design changes. In addition, landscape architecture in this kind of restoration project is bound to decrease in the future due to frequent changes in the hydraulic-centered design.

• Journal of The Korea Institute of Healthcare Architecture
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• v.22 no.1
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• pp.39-49
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• 2016

Purpose: This is the ex-post evaluation on "the Central General Hospital in Quang Nam Province in Vietnam" funded by Korean ODA. Through this evaluation, this study tries to explore useful ways to improve the effectiveness of Korean ODA projects related to hospital establishment. Methods: Field survey and analysis of questionaire to the staffs and patients of Quang Nam Province General Hospital were conducted twice in 2012 and 2014 after the completion of the Hospital. Two sets of surveys and questionaire outcomes have been comparatively analysed by statistics in order to seek the trend of satisfaction level of hospital users and find out the improvement way in hospital design and construction. Results: The satisfaction level on the hospital was relatively high and that of 2014 is higher than that of 2012. The satisfaction level of the users was recorded in Likert 5 scales. Continuous facility complement and maintenance is considered as the main contributor in increasing the satisfaction level of users. As far as the satisfaction level of outpatient is concerned, that of 2012 was recorded as 3.65 and that of 2014 was 4.05. In case of inpatient, the satisfaction level on the hospital in 2012 was 3.76, and 4.06 in 2014. Implications: In overseas hospital projects, proper hospital project management system including medical service plan, strategic plan, brief, design & construction and maintenance have to be put together effectively and efficiently for the success of the hospital project. At the same time local climate, culture, building material and local code have to be considered in order to build sustainable hospital.

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.417-422
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• 2009

Tunnels that have recently been constructed are characterized by longer length than ever before and furthermore they frequently go through the ground area with poor conditions such as fractured zones. If ground strength is weak, plastic deformation of tunnel occurs, and occasionally a big fall may be brought about. Up to now, the construction work of tunneling has been executed as a sequential method placing the lining concrete after completion of excavation. Such a method requires a long time and much money to complete the tunnel. It is hard to ensure the stability of tunnel if tunnel is left undone for a long time after excavation in fracture zones or plastic grounds. For this reason, we tried to take simultaneous construction of tunnel excavation and lining concrete in order to not only shorten construction schedule but also stabilize the tunnel at the highly fractures zone as soon as possible. As preliminary consideration for simultaneous construction, in-situ tests are performed to calculate the isolation distance over which blasting vibration does not influence the strength of lining concrete. Improvement of ling form, placing method of concrete, ventilation using a dust collector, together with equipment arrangement, was made to assure the simultaneous construction work.

• Korean Journal of Construction Engineering and Management
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• v.9 no.5
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• pp.127-136
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• 2008

The initial step in the construction process, estimating appropriate construction time and expense is the most important factor that would influence the result of the construction. In order to enhance productivity and efficiency, there is a need to analyze and manage rationally. The purpose of this project is to make a simulation model for all subway tunnel construction based on the NATM method, also give an support equipment that would make available to plan and analyze the construction. The development of simulation model is based on a real case construction analysis process and also on the reference data. It reflects restrictive elements, make it possible to modify the conditions, and not only adapt to our project's construction but other projects as well. The model developed by this project will be able to reasonably predict the construction completion time and support the process of decision making during the planning. Therefore we can expect the productivity and efficiency of the whole construction projects.

• Journal of the Korea Society of Computer and Information
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• v.16 no.7
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• pp.13-23
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• 2011

Grid computing is a new generation computing technology which organizes virtual high-performance computing system by connecting and sharing geographically distributed heterogeneous resources, and performing large-scaled computing operations. In order to maximize the performance of grid computing, job scheduling is essential which allocates jobs to resources effectively. Many studies have been performed which minimize total completion times, etc. However, resource costs are also important, and through the minimization of resource costs, the overall performance of grid computing and economic efficiency will be improved. So in this paper, we propose a multi-objective job scheduling model considering both time and cost. This model derives from the optimal scheduling solution using NSGA-II, which is a multi objective genetic algorithm, and guarantees the effectiveness of the proposed model by executing experiments with those of existing scheduling models such as Min-Min and Max-Min models. Through experiments, we prove that the proposed scheduling model minimizes time and cost more efficiently than existing scheduling models.