• Steel and Composite Structures
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• v.34 no.5
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• pp.681-698
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• 2020

The paper addresses contribution to the modeling and optimization of major machinability parameters (cutting force, surface roughness, and tool wear) in finish dry hard turning (FDHT) for machinability evaluation of hardened AISI grade die steel D₃ with PVD-TiN coated (Al₂O₃-TiCN) mixed ceramic tool insert. The turning trials are performed based on Taguchi's L₁₈ orthogonal array design of experiments for the development of regression model as well as adequate model prediction by considering tool approach angle, nose radius, cutting speed, feed rate, and depth of cut as major machining parameters. The models or correlations are developed by employing multiple regression analysis (MRA). In addition, statistical technique (response surface methodology) followed by computational approaches (genetic algorithm and particle swarm optimization) have been employed for multiple response optimization. Thereafter, the effectiveness of proposed three (RSM, GA, PSO) optimization techniques are evaluated by confirmation test and subsequently the best optimization results have been used for estimation of energy consumption which includes savings of carbon footprint towards green machining and for tool life estimation followed by cost analysis to justify the economic feasibility of PVD-TiN coated Al₂O₃+TiCN mixed ceramic tool in FDHT operation. Finally, estimation of energy savings, economic analysis, and sustainability assessment are performed by employing carbon footprint analysis, Gilbert approach, and Pugh matrix, respectively. Novelty aspects, the present work: (i) contributes to practical industrial application of finish hard turning for the shaft and die makers to select the optimum cutting conditions in a range of hardness of 45-60 HRC, (ii) demonstrates the replacement of expensive, time-consuming conventional cylindrical grinding process and proposes the alternative of costlier CBN tool by utilizing ceramic tool in hard turning processes considering technological, economical and ecological aspects, which are helpful and efficient from industrial point of view, (iii) provides environment friendliness, cleaner production for machining of hardened steels, (iv) helps to improve the desirable machinability characteristics, and (v) serves as a knowledge for the development of a common language for sustainable manufacturing in both research field and industrial practice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6004-6013
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• 2014

The research on resource sharing in the diversification field is concerned mainly with sharing, but there has been little interest in resources. This research examined resource sharing with the main variables and logics of resource-based view. Based on a survey of 263 affiliates of 35 diversified firms, the impacts of resource quantity, resource quality, and resource exploitability on inter-affiliate resource sharing were hypothesized and verified. To confirm the performance implications of resource sharing, the impacts of the combination of resource quantity and resource sharing, the combination of resource quality and resource sharing, and the combination of resource exploitability and resource sharing on the affiliate performance were also hypothesized and verified. According to the empirical results from multiple regression analyses, resource sharing increases in the order of low resource quantity, high resource quality, and high resource exploitability. The performance was advanced in resource sharing under a low resource quantity and resource sharing under high resource exploitability, but it was not advanced in resource sharing under high resource quality. The results highlight the need for a further study on why the resource quality and resource exploitability affect resource sharing in the opposite directions, as expected in the hypotheses, why resource sharing under high resource quality does not lead to high performance, even though resource quality increases resource sharing, and what they would be if resources are subdivided by the types.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.560-567
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• 1997

A new approach to obtain stable $W_1/O/W_2$ multiple emulsions has been studied ; The basis of the interfacial interaction between a PCL-PEO-PCL triblock copolymer and a lipophilic emulsifier in the dispersed oil phase was examined. $W_1/O/W_2$ multiple emulsions were prepared by the two-step method. Arlacel P-l35 was used as a liphophilic emulsifier and Synperonic PE/F 127 as a hydrophilic one. Eutanol-G was used as an oil phase. NaCl was encapsulated within the multiple emulsion droplets as the internal marker and its release rate studies were carried out. The suability of the multiple emulsions have been assessed by measuring Separation Ratios(%) and microscopic observations. The release of NaCl was significantly reduced in $W_1/O/W_2$ multiple emulsions containing PCL-PEO-PCL triblock copolymer(2k-4k-2k or 6k-4k-6k) in the oil phase. It may be concluded that the copolymer and the emulsifier form effective interfacial complex to enhance stability and to control the release rate. The effective diffusion coefficients of the NaCl were estimated as $2.64{\times}10^{-15}s$and $3.23{\times}10^{-16}gcm^2/s$ for the $W_1/O/W_2$ multiple emulsion containing 1.2 wt % of PCL-PEO-PCL triblock copolymers with compositions of 2k-4k-2k and 6k-4k-2k, respectively. The rate of release decreased with the increase of the initial concentration of NaCl. The results were examined in view of Higuchi mechanism. A kinetic model which is similar to the model for release of dispersed drugs from a polymeric matrix was found to be suitable for the release of NaCl from $W_1/O/W_2$ multiple emulsions.

• The Journal of Fisheries Business Administration
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• v.14 no.1
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• pp.19-43
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• 1983

Mankind has made traditional use of various ocean resources in such several forms as fish, plants food, means of transportation, and military purpose, followed by the recent exploitation of offshore subsoil or sea-bed minerals, energies, and utilization of ocean space. These available ocean resources come from the marine natural environment which has a distinct feature in view of the relationship between human wants and their capacity to meet them. Though these socially basic resources however bring forth the so-called scarcity or differential rent, their communal nature of ownership dissipates free gifts of nature endowed to society as a whole. Thus to maximize these rents and social welfare thereof, rents should be secured and preserved through a well-defined arrangements of property-ownership as well as appropriate comparison of competing uses of marine resources, taking full cognizance of their irreversible adverse effects of a specific choice on the alternatives. Here I showed the sources of rent yielded from the multiple uses of navigation, fishery, mariculture, minerals, and recreation site, and also summarized the presently widely-known analytic tool to measure these rents with emphasis on due care of the telescopic faulty of the appraiser in charge, viewed from the communal point, Finally, as communal property is in strict sense owned by the public at large, notwithstanding the restricted communal ownership at government or local governments control, effectiveness of competition I expect should be kept while transferring claims of these resources from the legal owner to private enterprise as well as while extracting their rent by her. In particular, various national or social objectives look forward to tile maximization of social efficiency. Discretionary system in noncompetitive method thus, is exceptionally suggested because of probable suspicion from the public whether these resources are transferred as a give away or not in discretion. And these realized rent payments, I propose, should be wisely taken advantage of in advancement of scientific research in marine nature to bring an incremental rent therefrom successively.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.553-561
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• 2002

We present a novel service discipline, called linear service discipline, to serve multiple QoS queues sharing a resource and analyze its properties. The linear server makes the output traffic and the queueing dynamics of individual queues as a linear function of its input traffic. In particular, if input traffic is Gaussian, the distributions of queue length and output traffic are also Gaussian with their mean and variance being a function of input mean and input power spectrum (equivalently, autocorrelation function of input). Important QoS measures including buffer overflow probability and queueing delay distribution are also expressed as a function of input mean and input power spectrum. This study explores a new direction for network-wide traffic management based on linear system theories by letting us view the queueing process at each node as a linear filter.

• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.45-52
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• 2006

This paper presents an image-space algorithm to real-time collision detection, which is run completely by GPU. For a single object or for multiple objects with no collision, the front and back faces appear alternately along the view direction. However, such alternation is violated when objects collide. Based on these observations, the algorithm propose the depth peeling method which renders the minimal surface of objects, not whole surface, to find colliding. The Depth peeling method utilizes the state-of-the-art functionalities of GPU such as framebuffer object, vertexbuffer object, and occlusion query. Combining these functions, multi-pass rendering and context switch can be done with low overhead. Therefore proposed approach has less rendering times and rendering overhead than previous image-space collision detection. The algorithm can handle deformable objects and complex objects, and its precision is governed by the resolution of the render-target-texture. The experimental results show the feasibility of GPU-based collision detection and its performance gain in real-time applications such as 3D games.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1677-1688
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• 1998

In this paper, we analyze the performance of a DS-CDMA system employing adaptive adaptive array antenna technology at base-station. For the analysis the receiving architecture of a multiple team adaptive base-station array antenna is proposed as a major system omponent, and signal to interference and noise ratio(SINR) on the proposed architecture is developed. We show that the perfomance enhancement of the CDMA system is represented as great reduction of interfreence by employing an array antenna capable of resolving the angular distribution of the mobile users as seen at the ase-station. The energy associated with each mobile or a group of mobiles is thus confined within the addressed volume, greatly reducing the amount of co-channel interference experienced from and by neighboring co-channel cells. In order to ascertain the benefits of such an antenna, a theoretical approach, which eis based on the conventional and proposed antenna systems in a typical mobile radio environment, is adopted. Finally computer simulation results show the insight into how the adaptive array antenna operates when used in conjunction with DS-CDMA and illustrate the potential benefits in the SINR point of view.

• Korean Journal of Social Welfare
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• v.56 no.2
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• pp.311-326
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• 2004

This article focuses on the use of case management in the Self-support program. Case management is a service modality which provides integrated services for people with multiple needs in the community. The goal to accomplish self-sufficiency of working participants in Self-Support Programs is positively affected by the efforts to reduce high social risks they are exposed. It is recommended that the agencies running Self-support programs apply case management to increase the quality of lives as well as the effectiveness of exiting statuses of conditional welfare recipients. Several service considerations of case management are recommended for the change in the structure and functioning of the Self-Support Program: Integrated view and contextualized thinking, empowerment-oriented approach, and a development of the community support system through networking. Types of case management and practice roles of the case manager applicable to the Self-Support Program are also recommended. Structural aspects of an organization, inter-organizational linkages and contextual factors need to be considered to improve problematic conditions that have not enough resources and appropriate authorities in providing case management functions.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.72-77
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• 2008

Identification of humans from multiple view points is an important task for surveillance and security purposes. For optimal performance the system should use the maximum information available from sensors. Multimodal biometric systems are capable of utilizing more than one physiological or behavioral characteristic for enrollment, verification, or identification. Since gait alone is not yet established as a very distinctive feature, this paper presents an approach to fuse face and gait for identification. In this paper we will use the single camera case i.e both the face and gait recognition is done using the same set of images captured by a single camera. The aim of this paper is to improve the performance of the system by utilizing the maximum amount of information available in the images. Fusion in considered at decision level. The proposed algorithm is tested on the NLPR database.

• Journal of the Korean Geographical Society
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• v.48 no.3
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• pp.466-481
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• 2013

The purpose of this research is to propose a model for education for sustainable development (ESD) within the geography curriculum. The study consists of two parts. The first part discusses the normal view of a model to assess the curriculum, namely the content and the cognitive dimensions. The ESD component necessitates an action program with skills and citizenship considered as the Objective Dimension. The second part of the paper examines the means for adding the Objective Dimension which follows a taking action approach through knowledge, skills, and citizenship that are consistent with ESD goals. The research procedure applied the methodology of the Delphi process. The theoretical model was initially developed by the researchers based on current practices in geography assessment in South Korea and the U.S. The model was tested using the Delphi technique by high school geography teachers and geography education faculty members in both countries who were recognized experts in their field. The research complements the curriculum and instructional activities that have been under way with the United Nations Decade of Education for Sustainable Development (UNDESD). The model may be used to deliberate proposals for building an ESD component into existing assessment practices.