• 한국기계연구소 소보
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• s.19
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• pp.117-123
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• 1989

This study is to develop interactive program for work-cell layout of SACARA type robot by using PC. To make this program interactively, we made use of the software which has the function of menu, dialog box, and graphic. By using the mouse, we can progress this program quickly and easily. It has 2Y2 dimension and provides that one can layout elements (robot, peripheral device, and etc.), create work path, and calculate cycle time of working robot. By comparing with cycle times of any number of work-cell layout for same work, we can evaluate work-cell layout. Finally, we can select one work-cell layout to be considered optimal one which has the least cycle time.

• Journal of Information Processing Systems
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• v.13 no.5
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• pp.1320-1330
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• 2017

Wireless sensor networks for forest monitoring are typically deployed in fields in which manual intervention cannot be easily accessed. An interesting approach to extending the lifetime of sensor nodes is the use of energy harvested from the environment. Design constraints are application-dependent and based on the monitored environment in which the energy harvesting takes place. To reduce energy consumption, we designed a power management scheme that combines dynamic duty cycle scheduling at the network layer to plan node duty time. The dynamic duty cycle scheduling is realized based on a tier structure in which the network is concentrically organized around the sink node. In addition, the multi-paths preserved in the tier structure can be used to deliver residual packets when a path failure occurs. Experimental results show that the proposed method has a better performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5389-5396
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• 2012

In this paper, an optimized residual data decoder architecture is proposed to improve the performance in H.264/AVC. The proposed architecture is an integrated architecture that combined parallel inverse transform architecture and parallel inverse quantization architecture with common operation units applied new inverse quantization equations. The equations without division operation can reduce execution time and quantity of operation for inverse quantization process. The common operation unit uses multiplier and left shifter for the equations. The inverse quantization architecture with four common operation units can reduce execution cycle of inverse quantization to one cycle. The inverse transform architecture consists of eight inverse transform operation units. Therefore, the architecture can reduce the execution cycle of inverse transform to one cycle. Because inverse quantization operation and inverse transform operation are concurrency, the execution cycle of inverse transform and inverse quantization operation for one $4{\times}4$ block is one cycle. The proposed architecture is synthesized using Magnachip 0.18um CMOS technology. The gate count and the critical path delay of the architecture are 21.9k and 5.5ns, respectively. The throughput of the architecture can achieve 2.89Gpixels/sec at the maximum clock frequency of 181MHz. As the result of measuring the performance of the proposed architecture using the extracted data from JM 9.4, the execution cycle of the proposed architecture is about 88.5% less than that of the existing designs.

• Journal of applied mathematics & informatics
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• v.34 no.3_4
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• pp.227-237
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• 2016

In this paper we introduce a new graph labeling called k-prime cordial labeling. Let G be a (p, q) graph and 2 ≤ p ≤ k. Let f : V (G) → {1, 2, . . . , k} be a map. For each edge uv, assign the label gcd (f(u), f(v)). f is called a k-prime cordial labeling of G if |v_f (i) − v_f (j)| ≤ 1, i, j ∈ {1, 2, . . . , k} and |e_f (0) − e_f (1)| ≤ 1 where v_f (x) denotes the number of vertices labeled with x, e_f (1) and e_f (0) respectively denote the number of edges labeled with 1 and not labeled with 1. A graph with a k-prime cordial labeling is called a k-prime cordial graph. In this paper we investigate the k-prime cordial labeling behavior of a star and we have proved that every graph is a subgraph of a k-prime cordial graph. Also we investigate the 3-prime cordial labeling behavior of path, cycle, complete graph, wheel, comb and some more standard graphs.

• Proceedings of the Technology Innovation Conference
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• 2003.02a
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• pp.63-77
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• 2003

In this paper, we investigate the co-movements of the real GDP cycle and the telecommunications service expenditure cycle over 1980 through 2000 in Korea. We used several appropriate statistical tools to characterize and to compare the co-movements between the two aforementioned variables. The statistics presented in this paper are common, easy to Interpret and capture important visual, descriptive information and the dynamics of data that would be lost if one focused only on the unconditional correlation coefficients of de-trended data. This paper examines four possible characteristics for the co-movements of real GDP and telecommunications service expenditure in Korea. The first is that in low frequency, the cyclical movements in telecommunications service expenditure are very similar to the cyclical movements in real GDP, The second is that in the high frequency, the estimated stationary cyclical telecommunications service expenditure is not closely related to the estimated stationary cyclical real GDP. Third, according to co-spectra analysis, the strong relationships between the variables are found in the mid-term frequency and as such this empirical finding has important implications for telecommunications policy and telecommunications service implementation strategies. Finally, in the short-term period, our empirical results support telecommunications network theories such as path dependence properties, lock-in, positive feedback externality, and network externality.

• Korean Journal of Mathematics
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• v.25 no.2
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• pp.279-301
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• 2017

An L(3, 2, 1)-labeling for the graph G = (V, E) is an assignment f of a label to each vertices of G such that ${\mid}f(u)-f({\upsilon}){\mid}{\geq}4-k$ when $dist(u,{\upsilon})=k{\leq}3$. The L(3, 2, 1)-labeling number, denoted by ${\lambda}_{3,2,1}(G)$, for G is the smallest number N such that there is an L(3, 2, 1)-labeling for G with span N. In this paper, we compute the L(3, 2, 1)-labeling number ${\lambda}_{3,2,1}(G)$ when G is a cylindrical grid, which is the cartesian product $P_m{\Box}C_n$ of the path and the cycle, when $m{\geq}4$ and $n{\geq}138$. Especially when n is a multiple of 4, or m = 4 and n is a multiple of 6, then we have ${\lambda}_{3,2,1}(G)=11$. Otherwise ${\lambda}_{3,2,1}(G)=12$.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.975-983
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• 2022

This paper presents an innovative way of integrating scheduling and project controls with the environmental impact of a construction project to track, monitor, and manage environmental emissions at the activity level. As a starting point, scheduling and project controls help monitor the status of a project to provide an assessment of the duration and sequence of activities. Additionally, project schedules can also reflect resource allocation and costs associated with various phases of a construction project. Owners, contractors and construction managers closely monitor tasks or activities on the critical path(s) and/or longest path(s) calculated through network based scheduling techniques. However, existing industry practices do not take into account environmental impact associated with each activity during the life cycle of a project. Although the environmental impact of a project may be tracked in various ways, that tracking is not tied to the project schedule and, as such, generally is not updated when schedules are revised. In this research, a Cradle to Gate approach is used to estimate environmental emissions associated with each activity of a sample project schedule. The research group has also investigated the potential determination of scenarios of lowest environmental emissions, just as project managers currently determine scenarios with lowest cost or time. This methodology can be scaled up for future work to develop a library of unit emissions associated with commonly used construction materials and equipment. This will be helpful for project owners, contractors, and construction managers to monitor, manage, and reduce the carbon footprint associated with various projects.

• Journal of Korea Multimedia Society
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• v.20 no.4
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• pp.640-648
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• 2017

Sensors have limited resources in sensor networks, so efficient use of energy is important. In order to use the energy of the sensor node efficiently, researches applying mobile sink to the sensor network have been actively carried out. The sink node moves the sensor network, collects data from each sensor node, which spread the energy concentrated around the sink node, thereby extending the entire life cycle of the network. But, when the sink node moves, it requires a reset of the data transmission path, which causes a lot of control messages and delays. In this paper, we propose a CMS(Cluster-based Mobile Sink) method to support the movement of mobile sink in a cluster sensor environment. The proposed scheme minimizes an amount of control messages without resetting the routing paths of entire sensor networks by supporting the sink mobility path using the neighbor cluster list. And, it simplifies the routing path setup process by setting a single hop path between clusters without a gateway. The experiment results show that the proposed scheme has superior energy efficiency in processing and network structure, compared with existing clustering and mesh routing protocols.

• Journal of Engineering Education Research
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• v.18 no.1
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• pp.11-19
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• 2015

This paper presumes the size and status of the deviation from S&T workforce career-path throughout the whole life cycle. For this purpose, we make a operational definition and analyzing framework for career departure of S&T workforce and then find out some results as followings. For example, the career departure is more serious in the utilization phase of S&T workforce than the training phase and the qualitative career departure is a still more important problem at both phase. Finally, we suggest some policy implications to solve these problems.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.3
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• pp.91-100
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• 2017

The solution was developed for the maintenance decision support of combined cycle power plant gas turbine. The developed solution was applied to MHI501G gas turbine and is, in present, on the process of field test at GUNSAN combined cycle power plant, South Korea. The developed solution provides the calculated result of optimal overhaul maintenance period through following modules: Real Time Performance Monitoring, Model-Based Diagnostics, Performance Trend Analysis, Optimal Overhaul Maintenance Interval, Compressor Washing Period Management, and Blade Path Temperature Analysis. Model-Based Diagnostics module analyzed the differences between the data of gas turbine performance model and the online measurement. Compressor washing management module suggests the optimal point of balancing between the compressor performance and the maintenance cost.