• Journal of the Korean Mathematical Society
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• v.43 no.5
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• pp.1047-1063
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• 2006

Let $\varepsilon_#(X)$ be the subgroups of $\varepsilon(X)$ consisting of homotopy classes of self-homotopy equivalences that fix homotopy groups through the dimension of X and $\varepsilon_*(X) $ be the subgroup of $\varepsilon(X)$ that fix homology groups for all dimension. In this paper, we establish some connections between the homotopy group of X and the subgroup $\varepsilon_#(X)\cap\varepsilon_*(X)\;of\;\varepsilon(X)$. We also give some relations between $\pi_n(W)$, as well as a generalized Gottlieb group $G_n^f(W,X)$, and a subset $M_{#N}^f(X,W)$ of [X, W]. Finally we establish a connection between the coGottlieb group of X and the subgroup of $\varepsilon(X)$ consisting of homotopy classes of self-homotopy equivalences that fix cohomology groups.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.534-537
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• 1998

In this paper, a set of novel self-timed latches are introduced and analyzed. These latches have no back-to-back connection as in conventional self-timed latch, and both inverting and noninerting outputs are evaluated simultaneously leading to thigher oepating frequencies. Power consumption of these latches ar ealso comparable to or less than that of conventional circuits. Novel type of cross-coupled inverter used in the proosed circuits implements static operatin without signal fighting with the main driver during signal transition. Proposed latches ar tested using a 0.6.mu.m triple-poly triple-metal n-well CMOS technology. The resutls indicates that proposed active-low sefl-timed latch (ALSTL) improves speed by 14-34% over conventional NAND SR latch, while in active-high self-timed latch (AHSTL) the improvements are 15-35% with less power as compared with corresponding NORA SR latch. These novel latches have been successfully implemented in a high-speed synchronous DRAM (SDRAM).

• Journal of Industrial Technology
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• v.24 no.A
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• pp.99-107
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• 2004

This paper considers reinforcement learning control with the self-organizing map. Reinforcement learning uses the observable states of objective system and signals from interaction of the system and the environments as input data. For fast learning in neural network training, it is necessary to reduce learning data. In this paper, we use the self-organizing map to parition the observable states. Partitioning states reduces the number of learning data which is used for training neural networks. And neural dynamic programming design method is used for the controller. For evaluating the designed reinforcement learning controller, an inverted pendulum of the cart system is simulated. The designed controller is composed of serial connection of self-organizing map and two Multi-layer Feed-Forward Neural Networks.

• Convergence Security Journal
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• v.22 no.2
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• pp.77-90
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• 2022

Domestic and foreign automakers compete to lead the autonomous vehicle industry through continuously developing self-driving technologies. These self-driving technologies are evolving with dependencies on the connection between vehicles and other objects such as the environment of cars and roads. Therefore, cyber security vulnerabilities become more likely to occur in the self-driving environment, so it is necessary to prepare for them carefully. In this paper, we model the threats in autonomous vehicles and make the checklist to securely countermeasure them.

• Structural Engineering and Mechanics
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• v.39 no.2
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• pp.241-266
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• 2011

The Self Compacting Concrete, SCC is the new generation type of concrete which is not needed to be compacted by vibrator and it will be compacted by its own weight. Since SCC is a new innovation and also the high strength self compacting concrete, HSSCC behavior is like a brittle material, therefore, understanding the strength effect on the serviceability performance of reinforced self compacting concretes is critical. For this aim, first the normal and high strength self compacting concrete, NSSCC and HSSCC was designed. Then, the serviceability performance of reinforced connections consisting of NSSCC and HSSCC were investigated. Twelve reinforced concrete connections (L = 3 m, b = 0.15 m, h = 0.3 m) were simulated, by this concretes, the maximum and minimum reinforcement ratios ${\rho}$ and ${\rho}^{\prime}$ (percentage of tensile and compressive steel reinforcement) are in accordance with the provision of the ACI-05 for conventional RC structures. This study was limited to the case of bending without axial load, utilizing simple connections loaded at mid span through a stub (b = 0.15 m, h = 0.3 m, L = 0.3 m) to simulate a beam-column connection. During the test, concrete and steel strains, deflections and crack widths were measured at different locations along each member. Based on the experimental readings and observations, the cracked moment of inertia ($I_{cr}$) of members was determined and the results were compared with some selective theoretical methods. Also, the flexural crack widths of the members were measured and the applicability for conventional vibrated concrete, as for ACI, BS and CSA code, was verified for SCCs members tested. A comparison between two Codes (ACI and CSA) for the theoretical values cracking moment is indicate that, irrespective of the concrete strength, for the specimens reported, the prediction values of two codes are almost equale. The experimental cracked moment of inertia $(I_{cr})_{\exp}$ is lower than its theoretical $(I_{cr})_{th}$ values, and therefore theoretically it is overestimated. Also, a general conclusion is that, by increasing the percentage of ${\rho}$, the value of $I_{cr}$ is increased.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.5
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• pp.320-331
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• 2023

In this study, a model test was conducted using the soft-mooring technique to evaluate the added resistance of the ship in waves. The study also examined the specific factors that should be considered during the soft-mooring test. The main purpose of soft-mooring is to prevent drifting caused by waves by providing horizontal restoring forces. However, it can also create undesired restoring forces in the vertical direction. Therefore, we examined the restoring force of the ship's 6-DOF motion based on the arrangement of the soft-mooring and the height of the mooring connection point. We also checked the corresponding resonance period and drift distance. The soft-mooring test was conducted twice, once with self-propulsion and once without self-propulsion, allowing us to review the advantages and disadvantages of each test technique. The main parameters measured in these model tests were 6DOF motion and added resistance on the ship. We compared these measurements obtained from two different techniques (with and without self-propulsion). Additionally, we also compared the measurements based on the types of measuring sensors used (2D load cells on FP, AP, and 1D load cells on each mooring line) as well as the height of the mooring connection point.

• Journal of Korean Public Health Nursing
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• v.29 no.2
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• pp.190-202
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• 2015

Purpose: This study was designed to determine visiting nurses' job performance and self confidence by career and number of visiting households. Methods: The subjects were 120 visiting nurses fully in charge of the visiting health care program working in 18 community health care centers, who were checked for 5 domains of visiting nurses' job, 39 tasks of job performance and self confidence. ANOVA test, Scheffe test and Pearson correlation coefficient were used for data analysis. Results: The level of job performance and self confidence indicated highest in understanding of the visiting health care program among 5 domains of visiting nurses' job. The level of job performance and self confidence indicated lowest in community resource connection. When nurses were classified by a career with approximately 5 years of working experience, nurses with a career of more than 5 years were highly significant. Job performance and self confidence were positively correlated. Conclusion: Based on the result of this study, it is recommended that the education program for newly hired nurses should be differentiated from that for visiting nurses with a career in order to improve quality of the visiting nursing program and capacity of residents' health care.

• Korean journal of applied entomology
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• v.22 no.2 s.55
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• pp.106-129
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• 1983

An emphasized analysis and reviews on the progress of pesticide managements for the past 10 years through the statistics in Korea are summarized in this continued studies in connection with the fundmental aspects and direction of advanced pesticide industry and improved plantprotection policies for 1980's. Remarkable development and changes are observed in the plant species and varieties, plantation practices and production techniques as well as pest infestations and controls in the last decade, but no normal achievement and operations are recognised on the pesticide management and marketing system especially. Realistic plant protection adminstration and pesticide regulations in accordance to the industrial modernization and pest management advancement must be adjusted in accordance with national economic progress and desirable agricultural structure for 1980's. Special considerations are stated on the strengthening of research and inspection program for the quality products and control with the efficacy and safety use of pesticides. More serious attentions are noted on the over production and flooded stocks under struggled market demands and sales competitions with lethal financial difficulties by producers. Through the status analyzed for the last decade, the integrated past management and cooperative basic control pattern under positive self-forecasting system by farmers are also urged for the effective and economic pest control measures. The problems and solutions discussed here ell the advanced pesticide management as well as the cooperation on the self-ordered quality control and market managing systems in 1980's as it is a desired projection for the further improvement. Most of outstanding and necessary statistics and data in the past decade are also summarized here for references in connection with the previous report.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.1
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• pp.1-8
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• 2018

A problem exists in the conventional transportation cart applications, in which an external power supply with mechanical contact connection (bus bar connection) is required to drive the motor. Therefore, continuous effort for maintenance is required, aside from the expensive bus bar connector. To solve this problem, a self-electricity-generated transportation cart system without bus bar has recently been introduced. In this system, a battery needs to store the power of the generated wheel, and a boost converter, which converts the low battery voltage to high bus voltage to drive the motor inverter, is necessary. However, since the instantaneous large current required for starting the motor is supplied from the battery, a battery with large size and volume should be adopted to withstand this large current. In this study, a boost converter that can supply a large instantaneous current by using super Capacitor string is proposed. The proposed converter can be realized with a small size and volume compared with the conventional battery-fed boost converter. Operational principles, analysis, and design of the proposed converter are presented, and experimental results are provided to validate the proposed converter.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.6
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• pp.63-68
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• 2007

The purpose of this study was to develop a new connection method between steel beams and PC columns known as SL connectors. Composite moment frames consisting of PC columns (or composite columns) and steel beams make the best use of advantages of both concrete and steel materials. However, the connection between two members of different materials can be complex and/or increase the fabrication costs significantly. The concept of SL connectors is based on using wedges and the emphasis is on a self-locking (SL) feature. SL connectors are easy to install and provide better seismic performance compared to conventional connections. To evaluate the seismic performance of the steel beam-to-PC column joints with SL connectors, cyclic load tests were conducted. Test result showed that steel beam-to-concrete column joint with SL connectors was able to provide sufficient performance for use in seismic resistant moment frames.