• Journal of Engineering Education Research
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• v.6 no.1
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• pp.15-21
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• 2003

This paper reports the results of course restructuring employing design projects in an introductory mechanics of materials course at Pennsylvania State University. Unlike traditional lecture courses, students were encouraged to learn the rudiments of mechanical design and how materials standards, economics, manufacturing, environmental, legal (liability) and societal (safety) concerns relate to design. Through conducting collaborative design projects, the instructors helped students to acquire more advanced skills such as team-based decision making, integration and establishment of criteria, use of modern design theory, consideration of alternative solutions, and application of realistic constraints. In order to examine the impact of new course changes on students' learning, a survey was conducted in 1998 Fall semester. According to the results of survey analyses, students reported high values on this introductory mechanics of materials course. However, they did not give high values on the design projects. Rather, they preferred lecture sessions. Additionally, it was also found that students who earned higher grades from a prerequisite course(statics) showed lower values on the design projects. Implications for engineering educators and suggestions for future research studies were discussed.

• Journal of Broadcast Engineering
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• v.15 no.2
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• pp.173-181
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• 2010

In this paper, we propose a new resource allocation scheme for an OFDMA relay network with multicells. In the proposed scheme, by sharing the channel state information (CSI) between base stations, resources are allocated to users and relays to maximize the overall sum of the achievable rate under fairness constraints. In order to reduce the computational complexity, a resource allocation scheme is proposed by separating subcarrier allocation and power allocation into two parts. First of all, by considering inter-cell interference (ICI), a subcarrier is allocated to a user-relay pair, and power is allocated relays. Simulation results show that the proposed scheme achieves higher spectral efficiency per subcarrier than the static scheme and reduces the outage probability compared to the static and greedy schemes.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.9-18
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• 2011

In this paper, we propose a method which recognizes human activity using model-based gaze direction estimation in an indoor environment. The method consists of two steps. First, we detect a head region and estimate its gaze direction as prior information in the human activity recognition. We use color and shape information for the detection of head region and use Bayesian Network model representing relationships between a head and a face for the estimation of gaze direction. Second, we recognize event and scenario describing the human activity. We use change of human state for the event recognition and use a rule-based method with combination of events and some constraints. We define 4 types of scenarios related to the gaze direction. We show performance of the gaze direction estimation and human activity recognition with results of experiments.

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.2
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• pp.159-178
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• 1995

Supervisory control is an approach based on formal language. it is used to model and control discrete event systems in which each discrete event process is represented as an automation. A supervisor is a generator that switches control patterns in such a way that a given discrete evenet process behaves in obedience to various constraints. A flexible manufacturing cell (FMC) is one of discrete evenet systems. Functions necessary for the operation of an FMC are characterized by operational components and informational compoments. The operational components can be modeled using the finite state machines and the informational components can be modeled using the abstract formalism which describes supporting operations of the cell controller. In this paper, we addressed function required for FMC control specification, software engineering aspects on FMC control based on supervisory control, a concept of event queue for resolving synchronization problem, and complexity reduction. Based on the mathematical model of an FMC. we synthesized the controller by integrating a supervisor for FMC with control specification that specifies event-driven operation of the cell controller. The proposed control scheme is stable mathematically so that the system always behaves on a controlled way even under the existence of uncontrollable events. Furthermore, using an event queue concept, we can solve a synchronization problem caused by the violation of instantaneity assumption of supervisory control theory in real life situation. And also, we can propotype a control software rapidly due to the modularity of the proposed control scheme.

• 한국사회복지학회:학술대회논문집
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• 2004.06a
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• pp.3-50
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• 2004

${\cdot}$ Recent social policy and labour markets debates in Europe, responding to the difficulties faced by the traditional neo-Keynesian welfare state settlement, stress the value of positive investment alongside de-regulation and greater flexibility as a way of achieving both economic and social goals. ${\cdot}$ Patterns of policy reform are complex and reflect differing national circumstances. A general move towards deregulation, constraints on entitlement to passive benefits, programmes to enhance employment, particularly among high-risk groups such as single parents and young people, targeted subsidies for low earners and casemanagement may be identified. ${\cdot}$ In relation to investment in education, research and development and combined training and benefit programmes to enhance mobility between jobs the picture is less clear. Education standards continue to rise, but research and development spending stagnates and few countries have developed substantial ‘flexi-curity’ programmes to support job mobility. ${\cdot}$ The labour market tradition in much of Europe has been one of conflict between labour and employers. As labour grows weaker, new approaches develop. These tend to stress productivity agreements and greater flexibility in work practices within firms and reforms to passive social security systems more broadly, but movement to support the more challenging investment and flexi-curity policies is slow. ${\cdot}$ In general, social and labour market policies in Europe stress deregulation and negative activation more strongly than social investment and ‘flexi-curity’. The countries with high growth and employment achieve that goal by different routes: Sweden has a closely integrated social democratic corporatism with high spending on benefits and training programmes and the UK a more liberal market-oriented system, with lower spending, highly targeted benefits and less mobility support. ${\cdot}$ Europe has something to learn from Korea in achieving high investment in human capital and R and D, while Korea may have something to learn from Europe in social investment, particularly flexi-curity and equal opportunity policies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.107-110
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• 2015

In this paper, we propose a coalitonal game theoritic approach to the power control problem in resource-constrained wireless sensor networks, where the objective is to enhance power efficiency of individual sensors while providing the QoS requirements. We model this problem as two-sided one-to-one matching game and deploly deferred acceptance procedure that produces a single matching in the core. Furthermore, we show that, by applying the procedure repeatedly, a certain stable state is achieved where no sensor can anticipate improvements in their power efficiency as far as all of them are subject to their own QoS constraints. We evaluate our proposal by comparing them with cluster-based and the local optimal solution obtained by maximizing the total system energy efficiency, where the objective function is non-convex.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.3
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• pp.244-260
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• 2006

The main objective of this study aims at analyzing the national roles of fisheries in the global economy from the constitutional view point. Globalization provides general firms and businessmen with great opportunities that allow them to be able to plan and operate their business strategies beyond the national boundaries. WTO and FTA negotiations must be important facilitators of such globalization. However, Korean primary industries like fisheries under comparative disadvantage have a high probability that there may have to be the trade-offs between the primary and the industrial sector to maximize national benefits in the process of bilateral and/or multilateral international trade deals. Since, moreover, fishermen face strong binding constraints under which they hardly carry out fishing operations standing aloof from national boarders, they have to manage fishing businesses within their own national territory, to maintain and develop fisheries culture, and to explore their own destiny for themselves. Because of such reasons, the constitution imposes upon the State the duty to support and develop fisheries and fishing villages. Considering its article and spirit associated with fisheries(i.e. article 123), it seems unnecessary at this point in time that Korean society makes debates over national consensus for supporting fisheries. The reason is because the explicit provisions of the constitution do not allow their arbitrary interpretation depending upon interests or policy situations. However, where national support to the particular sector could not meet the expected social value system, there would be a great deal of chance to invite serious societal debates over such national commitment to the fisheries. Therefore, whether using it efficiently and realizing the socially expected policy goals must be a responsibility of both fisheries administration and fishing industries.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.540-550
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• 2016

Since energy efficiency has become a significant concern for network infrastructure, next-generation network devices are expected to have embedded advanced power management capabilities. However, how to effectively exploit the green capabilities is still a big challenge, especially given the high heterogeneity of devices and their internal architectures. In this paper, we introduce a hierarchical power management architecture (HPMA) which represents physical components whose power can be monitored and controlled at various levels of a device as entities. We use energy aware state (EAS) as the power management setting mode of each device entity. The power policy controller is capable of getting information on how many EASes of the entity are manageable inside a device, and setting a certain EAS configuration for the entity. We propose the optimal local control policy which aims to minimize the router power consumption while meeting the performance constraints. A first-order Markov chain is used to model the statistical features of the network traffic load. The dynamic EAS configuration problem is formulated as a Markov decision process and solved using a dynamic programming algorithm. In addition, we demonstrate a reference implementation of the HPMA and EAS concept in a NetFPGA frequency scaled router which has the ability of toggling among five operating frequency options and/or turning off unused Ethernet ports.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.261-274
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• 1999

Recently, automated business processing systems, so called workflow systems, have been studied. have been studied. even though each task has noticible duration inherently, most of previous models regard it as a simple finite automation where state transitions occur instantly. In this paper, we propose a modeling method for workflow each of whose component task has minimum processing time and due-date. Firstly we provide a priority function to choose the proper alternatives when tasks fail before their due-date. The priority function considers the time-relevant factor and the semantic compatibility level to decide the best alternative. secondly, we identify six different types of execution requirements for tasks with noticible durations. They are serial, parallel, simultaneous start simultaneous termination, interleaved and nested dependency. Note that previous models deal with only serial execution and parallel execution. Lastly, we also propose graph-based methods to detect logical conflicts in time constraint-based workflow specifications.

• The KIPS Transactions:PartB
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• v.13B no.2 s.105
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• pp.139-148
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• 2006

In the collaborative product design environment, the communication between designers is important to capture design intents and to share a common view among the different but semantically similar terms. The Semantic Web supports integrated and uniform access to information sources and services as well as intelligent applications by the explicit representation of the semantics buried in ontology. Ontologies provide a source of shared and precisely defined terms that can be used to describe web resources and improve their accessibility to automated processes. Therefore, employing ontologies on assembly modeling makes assembly knowledge accurate and machine interpretable. In this paper, we propose a framework of semantic assembly modeling using ontologies to share design information. An assembly modeling ontology plays as a formal, explicit specification of a shared conceptualization of assembly design modeling. In this paper, implicit assembly constraints are explicitly represented using OWL (Web Ontology Language) and SWRL (Semantic Web Rule Language). The assembly ontology also captures design rationale including joint intent and spatial relationships.