• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.361-367
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• 2014

This paper is related to a new solar power conditioner for a built-in step-up chopper function. In the first step-up chopper proposed solar PV power conditioner for mutually connected in series with the input voltage of the bypass diodes are respectively connected to the positive terminal should install the mutual boosting chopper diode connected in series with the boost chopper switching element between the two power supply and at the same time the first and the second was connected to a second diode and a resonance inductor and a snubber capacitor in series with each other. And the common connection point between the bypass diode and the step-up chopper and the step-up chopper diode common connection point of the switching elements of the input voltage was set to the boost inductor for storing energy. In addition, between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point of the first auxiliary diode and the second common connection point of the auxiliary diode was provided, the resonance capacitor. Between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point and the common connection point of the resonance inductor snubber capacitor and connecting the third secondary diode, between two power supply lines is characterized by configuring the DC link capacitor bus lines in parallel. Therefore, it is possible to suppress the switching loss through, DC link bus lines, as well as there could seek miniaturization and weight reduction of the power conditioner itself by using a common capacitor of the non-polar non-polar electrolytic capacitor having a capacitor, the service life of the circuit can be extended and it is possible to greatly reduce the loss can be greatly improve the reliability of the product and the operation of the product itself.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.2
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• pp.103-111
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• 2019

The IoT-driven large-scaled systems consist of connected things with on-chip executable embedded software. These light-weighted embedded things have limited hardware space, especially small size of on-chip flash memory. In addition, on-chip embedded software in flash memory is not easy to update in runtime to equip with latest services in IoT-driven applications. It is becoming important to develop light-weighted IoT devices with various software in the limited on-chip flash memory. The remote instruction execution in cloud via IoT connectivity enables to provide high performance software execution with unlimited software instruction in cloud and low-power streaming of instruction execution in IoT edge devices. In this paper, we propose a Cloud-IoT asymmetric structure for providing high performance instruction execution in cloud, still low power code executable thing in light-weighted IoT edge environment using remote instruction execution. We propose a simulated approach to determine efficient partitioning of software runtime in cloud and IoT edge. We evaluated the instruction cloudification using remote instruction by determining the execution time by the proposed structure. The cloud-connected instruction set simulator is newly introduced to emulate the behavior of the processor. Experimental results of the cloud-IoT connected software execution using remote instruction showed the feasibility of cloudification of on-chip code flash memory. The simulation environment for cloud-connected code execution successfully emulates architectural operations of on-chip flash memory in cloud so that the various software services in IoT can be accelerated and performed in low-power by cloudification of remote instruction execution. The execution time of the program is reduced by 50% and the memory space is reduced by 24% when the cloud-connected code execution is used.

• Journal of Communications and Networks
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• v.1 no.2
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• pp.89-98
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• 1999

In a synchronization (sync) $network^1$containing N nodes, it is shown (Theorem 1c) that an arbitrarily connected sync network & is the union of a countable set of isolated connecting sync networks${&_i,i= 1,2,.., L}, I.E., & = \bigcup_{I=1}^L&_i$ It is shown(Theorem 2e) that aconnecting sync network is the union of a set of disjoint irreducible subnetworks having one or more nodes. It is further shown(Theorem 3a) that there exists at least one closed irreducible subnetwork in $&_i$. It is further demonstrated that a con-necting sync network is the union of both a master group and a slave group of nodes. The master group is the union of closed irreducible subnetworks in $&_i$. The slave group is the union of non-colsed irre-ducible subnetworks in $&_i$. The relationships between master-slave(MS), mutual synchronous (MUS) and hierarchical MS/MUS ent-works are clearly manifested [1]. Additionally, Theorem 5 shows that each node in the slave group is accessible by at least on node in the master group. This allows one to conclude that the synchro-nization information avilable in the master group can be reliably transported to each node in the slave group. Counting and combinatorial arguments are used to develop a recursive algorithm which counts the number $A_N$ of arbitrarily connected sync network architectures in an N-nodal sync network and the number $C_N$ of isolated connecting sync network in &. EXamples for N=2,3,4,5 and 6 are provided. Finally, network examples are presented which illustrate the results offered by the theorems. The notation used and symbol definitions are listed in Appendix A.

• Communications of the Korean Mathematical Society
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• v.20 no.3
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• pp.443-456
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• 2005

Let G be a Lie group, let L(G) be its Lie algebra, and let exp : $L(G){\rightarrow}G$ denote the exponential mapping. For $S{\subseteq}G$, we define the tangent set of S by $L(S)\;=\;\{X\;{\in}\;L(G)\;:\;exp(tX)\;\in\;S\;for\;all\;t\;{\geq}\;0\}$. We say that a semigroup S is strictly infinitesimally generated if S is the same as the semigroup generated by exp(L(S)). We find a tangent set of the semigroup of all non-singular totally positive matrices and show that the semigroup is strictly infinitesimally generated by the tangent set of the semigroup. This generalizes the familiar relationships between connected Lie subgroups of G and their Lie algebras

• Kyungpook Mathematical Journal
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• v.47 no.2
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• pp.155-164
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• 2007

It is the objective of this paper to study further the notion of ${\Lambda}_s$-semi-${\theta}$-closed sets which is defined as the intersection of a ${\theta}$-${\Lambda}_s$-set and a semi-${\theta}$-closed set. Moreover, introduce some low separation axioms using the above notions. Also we present and study the notions of ${\Lambda}_s$-continuous functions, ${\Lambda}_s$-compact spaces and ${\Lambda}_s$-connected spaces.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.4
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• pp.135-142
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• 2011

This paper proposes a performance evaluation method for power consumption of set-top box (STB) stand-by mode transition schemes. A stand-by mode transition scheme characterizes the timing of mode transition. The timing of mode transition affects the duration of stand-by mode operation, and the power consumptions of STB as well. Recently a fast stand-by mode transition scheme (FMT) has been proposed based on user input for selecting the device to be connected to TV. In this paper, we evaluate power consumption of FMT and a conventional mode transition scheme. For the computation of the duration of stand-by mode operation, the user input events are modeled as Poisson process. Simulation results based on the modeling reveals that the proposed scheme is more effective in power saving than the conventional scheme by up to 30%.

• Journal of Ecology and Environment
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• v.38 no.2
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• pp.229-239
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• 2015

The southwestern islands of Japan, especially southward from Amamioshima Island, have distinguished sets of nature and culture. However, various problems are arising on those islands. This report first introduces island characteristics as well as, their status briefly. Then it introduces conservation efforts. Since nature and culture are closely connected in the island system, conservation of the set of nature and culture is essentially important. From this point of view, this report focuses on two efforts. The first example is the effort for designation of a new national park with a new concept of "environmental culture type" and "ecosystem management type" in the Amami Gunto Islands. This effort is a new challenge to focus on the importance of cultural aspects. The second example is the unique effort of the national park visitor center to conserve as one set of integrated nature and culture with an alliance of all stakeholders in Taketomijima Island, Iriomote-Ishigaki National Park. The visitor center serves not only visitors, but also islanders. These two cases are good models that suggest hints for future conservation measures.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.4
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• pp.368-374
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• 2011

This paper proposes a robot control human interface using Markov model (HMM) based hand signal recognizer. The command receiving humanoid robot sends webcam images to a client computer. The client computer then extracts the intended commanding hum n's hand motion descriptors. Upon the feature acquisition, the hand signal recognizer carries out the recognition procedure. The recognition result is then sent back to the robot for responsive actions. The system performance is evaluated by measuring the recognition of '48 hand signal set' which is created randomly using fundamental hand motion set. For isolated motion recognition, '48 hand signal set' shows 97.07% recognition rate while the 'baseline hand signal set' shows 92.4%. This result validates the proposed hand signal recognizer is indeed highly discernable. For the '48 hand signal set' connected motions, it shows 97.37% recognition rate. The relevant experiments demonstrate that the proposed system is promising for real world human-robot interface application.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.4
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• pp.571-581
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• 2022

Wireless sensor networks use the concept of connected dominating sets that can form virtual backbones for effective routing and broadcasting. In this paper, we propose an optimization algorithm that configures a connected dominating sets in order to balance the load of nodes to increase network lifetime and to perform effective routing. The proposed optimization algorithm in this paper uses the metaheuristic method of tabu search algorithm, and is designed to balance the number of dominatees in each dominator in the constituted linked dominance set. By constructing load-balanced connected dominating sets with the proposed algorithm, it is possible to extend the network lifetime by balancing the load of the dominators. The performance of the proposed tabu search algorithm was evaluated the items related to load balancing on the wireless sensor network, and it was confirmed in the performance evaluation result that the performance was superior to the previously proposed method.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.8
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• pp.440-444
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• 2002

This paper presents an efficient and robust algorithm to compute the isophote of a surface of revolution. A surface of revolution can be decomposed to a set of cross-sectional circles. The surface normals along each cross-sectional circle form a cone. Using the characteristics of the normal vectors and the symmetric property of the surface of revolution, we propose a method to find the connected components of an isophote, which requires intersecting a planar curve(and its reflection) with two rays. Moreover, we propose a closed-form representation of an isophote as a parametric curve.