• Journal of the Korean Institute of Gas
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• v.11 no.2 s.35
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• pp.60-64
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• 2007

Chemical Process industry in Korea has over 30 year's of history and is likely to face potential incidents. The traditional risk analysis and control system in Chemical Process industry focuses on mechanical defects, overlooking the human performance control. Although development of automation technology and controlling technology was necessary, human decision factor is essential to preventing accidents in the Chemical Process. Almost all serious accidents take place when inappropriate humanperformance and mechanical defects of safety equipments simultaneously occurs. The AHRA(Advanced Human Reliability Analyzer) software has been developed to collect failure data and analyze human error probability (Reliability) in Chemical Process Industry in Korea. This paper describes the HRA analysis result of PIF(Performance Influencing Factor) evaluation, HEP(Human Error Probability) and root cause of accidents by applying a Chemical Process Industry related accident data. This analysis result should present a scheme that, by controlling human error factor other than putting safety management funds into the machinery in plants, can reduce cost and maximize the safety in Chemical Process Industry.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.11
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• pp.592-600
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• 2001

To improve the performance of wide-issue Superscalar microprocessors, it is essential to increase the width of instruction fetch and issue rate. Data dependences are major hurdle to exploit ILP(Instruction-Level Parallelism) efficiently, so several related works have suggested that the limits imposed by data dependences can be overcome to some extent with the use of the data value prediction. But the suggested mechanisms may access the same value prediction table entry again before they have been updated with a real data value. They will cause incorrect value prediction by using stable data and incur misprediction penalty and lowering performance. In this paper, we propose a new hybrid value predictor which achieve high performance by reducing stale data. Because the proposed hybrid value predictor can update the prediction table speculatively, it efficiently reduces the number of mispredicted instruction due to stable due to stale data. For SPECint95 benchmark programs on the 16-issue superscalar processors, simulation results show that the average prediction accuracy increase from 59% for non-speculative update to 72% for speculative update.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.5
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• pp.581-588
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• 2019

In this paper, I propose an modified back-off algorithm to improve the fairness for slotted ALOHA sensor networks. In hierarchical networks, the performance degradation of a specific node can cause degradation of the overall network performance in case the data transmitted by lower nodes is needed to be synthesized and processed by an upper node. Therefore it is important to ensure the fairness of transmission performance to all nodes. The proposed scheme choose a back-off time of a node considering the previous transmission results as well as the current transmission result. Moreover a node that failed to transmit consecutively is given gradually shorter back-off time but a node that is success to transmit consecutively is given gradually longer back-off time. Through simulations, I compare and analyze the performance of the proposed scheme with the binary exponential back-off algorithm(BEB). The results show that the proposed scheme reduces the throughput slightly compared to BEB but improves the fairness significantly.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.109-117
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• 2020

In this paper, we analyze LADN(Local Area Data Network) that provides high throughput, low latency and service localization for 5G wireless networks and propose an enhanced control protocol design for LADN in 5G wireless networks. The concept of LADN is newly introduced in 3GPP 5G communication system and the LADN is a data network to which the UE(User Equipment) can connect with a specific LADN session only when the UE is located in a certain service area. If the LADN information between the UE and core network is not identical, the LADN session cannot be properly established. The proposed approach promplty synchronizes the LADN information between the UE and core network by using the specific registration procedure and appropriately establishes the LADN session, when the establishment of the LADN session is failed. Consequently, the proposed enhanced control protocol design(ECP) can prevent unnecessary signalling overhead and communication delay for LADN in 5G wireless networks.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.98-105
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• 2021

Recently, there have been many changes in the domestic construction industry. OSC (Off-Site Construction) is expected to solve these problems, and it is emerging as a way to inspire innovation in the domestic construction production system. OSC, which has only recently attracted attention again after previous studies have failed, is lacking in research on preception surveys and customized performance measurements compared to overseas. This study investigated the perceptions of construction industry workers on OSC through a survey, and examined differences in perceptions of each subject and the relative importance of performance indicators. In general, the need for introduction and development of OSC was recognized. Also, drivers and obstacles inhibiting more use of OSC were analyzed. The relative importance for performance indicators and differences in perceptions of each subject were identified. Then, this study suggests plans for diffusion and revitalization of OSC, and key performance indicator for OSC based PC structure apartment housing.

• The Journal of Korean Institute of Information Technology
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• v.17 no.12
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• pp.21-28
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• 2019

Side effects of drugs mean harmful and unintended effects resulting from drugs used to prevent, diagnose, or treat diseases. These side effects can lead to patients' death and are the main causes of drug developmental failures. Thus, various methods have been tried to identify side effects. These can be divided into biological and systems biology approaches. In this study, we use systems biology approach and focus on using various phenotypic information in addition to the chemical structure and target proteins. First, we collect datasets that are used in this study, and calculate similarities individually. Second, we generate a set of features using the similarities for each drug-side effect pair. Finally, we confirm the results by AUC(Area Under the ROC Curve), and showed the significance of this study through a comparison experiment.

• Journal of Internet of Things and Convergence
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• v.8 no.2
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• pp.71-78
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• 2022

Recently, the number of people wishing to return to farming is increasing, However, the lack of farming experience and management information of returnees is one of the main reasons for increasing the probability of agricultural failure. This study proposes an interface to support early facility cultivation management decision-making for returnees who want facility cultivation. The proposed interface is designed with UML(Unified Modeling Language) and provides key decision-making information such as land/crop suitability, land/facility costs, and management costs according to input data such as cultivation areas, selected crops, and cultivation types selected by the user. Through the proposed interface, facility cultivators can effectively and quickly acquire initial decision-making information for facility cultivation in the desired target area.

• Journal of Industrial Convergence
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• v.20 no.1
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• pp.63-68
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• 2022

In schools and corporate buildings, public WiFi Access Points are installed on the ceilings of hallways. In the case of an architectural structure in which a WiFi signal enters through a steel door made of a material with high signal attenuation, Internet connection is frequently cut off or fails when the door is closed. To solve this problem, our research implements an economical and portable WiFi extender using a Raspberry Pi and an auxiliary battery. Commercially available WiFi extenders have limitations in the location where the power plug is located, and WiFi extension using the WiFi hotspot function of an Android smartphone is possible only in some high-end models. However, because the proposed device can be installed at the position where the Wi-Fi reception signal is the best inside the door, the WiFi range can be extended while minimizing the possibility of damage to the original signal. Experimental results show that it is possible to eliminate the shadows of radio waves and to provide Internet services in the office when the door is closed, to the extent that web browsing and real-time video streaming for 720p are possible.

• Journal of the Korea Society for Simulation
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• v.18 no.2
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• pp.77-89
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• 2009

Visual tracking technique is one of the essential things which are very important in the major fields of modern society. While contour tracking is especially necessary technique in the aspect of its fast performance with target's external contour information, it sometimes fails to track target motion because it is affected by the surrounding edges around target and weak egdes on the target boundary. To overcome these weak points, in this research it is suggested that PDMs can be obtained by generating the virtual 6-DOF motions of the mobile robot with a CCD camera and the image tracking system which is robust to the local minima around the target can be configured by constructing Active Shape Model in modular base. To show the effectiveness of the proposed method, the experiment is performed on the image stream obtained by a real mobile robot and the better performance is confirmed by comparing the experimental results with the ones of other major tracking techniques.

• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.308-326
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• 2024

A comprehensive evaluation of cardiac function includes information in relation to cardiac output and systemic venous return. The heart is composed of four chambers: two atria and two ventricles, each with its own unique mechanical function. These four cardiac chambers, their valves, and the pulmonary circulation system are inter-related as they preload or afterload on each other. Cardiac dysfunction is a failure of global cardiac function, resulting in typical clinical manifestations. To investigate the underlying cause of cardiac dysfunction, a step-by-step evaluation of cardiac blood flow tracks is necessary. In this context, imaging markers showing details of the cardiac structures have an important role in assessing cardiac function. An image-based evaluation allows for investigation of function in terms of individual cardiac components. Evaluation of cardiac function using cardiac CT has recently been validated. This review aimed to discuss cardiac CT-based imaging markers for comprehensive and detailed cardiac function assessment.