• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.4
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• pp.86-93
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• 2023

A bridge health monitoring technology is under development for the safety management of aged bridges. The bridge health monitoring technology has been developed mainly for single bridge management at a large scale, so it uses wire-based systems for power supply and data transfer. However, the wire-based systems need to be improved for the sporadically distributed small-sized bridges on local roads. This study proposed a wireless structural health monitoring system for small-sized bridges. The proposed monitoring system overcomes the limitations of wired systems by providing wireless power through solar power and utilizing LTE technology to transmit measurement data. In addition, a remote control system and power management plan were proposed to ensure the stability of the bridge measurement system. The proposed measurement system was installed on 32 bridges on fields and verified the operability by collecting 80.6% of measurement data for one year. The proposed system can support the health monitoring of aged bridges on local roads.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.701-708
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• 2023

Local governments are required to take measures to prevent occupational accidents under Articles 4(2) and 4(3) of the Occupational Safety and Health Act, and this study suggested the necessity of establishing an IT-based integrated safety and health information sharing system for serious accident reduction and safety and health management through the case of Incheon Metropolitan City. Recently, as local governments have established labor and health ordinances and basic plans, the need for an independent integrated safety and health management system based on local industrial characteristics has increased. It is necessary to establish a cooperation and support system with basic local governments and hub institutions, share integrated safety and health information with related institutions and organizations, and play a pivotal role in regional safety and health management by managing occupational accident statistics and implementing basic policies. The system through local governments' safety and health management will reduce serious accidents in the region, and the comprehensive safety and health management system for small businesses and projects ordered by local governments will strengthen the operability of the site, which will be effective in preventing critical accidents and industrial accidents.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.238-247
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• 2023

Liquefied petroleum gas (LPG) is an attractive fuel for ships considering its current technology and economic viability. However, safety guidelines for LPG-fueled ships are still under development, and there have been no cases of applying LPG propulsion systems to small and medium-sized ships in Korea. The purpose of this study was to perform an objective risk assessment for the first marine LPG engine system and propose safe operational standards. First, hazard and operability (HAZOP) analysis was used to divide the engine system into five nodes, and 58 hazards were identified. To compensate for the subjectivity of qualitative evaluation using HAZOP analysis, fuzzy set theory was used, and additional risk factors, such as detectability and sensitivity, were included to compare the relative weights of the risk factors using a fuzzy analytical hierarchy process. As a result, among the five risk factors, those with a major impact on risk were determined to be the frequency and severity. Finally, the fuzzy technique for order of preference by similarity to ideal solution (TOPSIS) was applied to select the risk rank more precisely by considering the weights of the risk factors. The risk level was divided into 47 groups, and the major hazard during the operation of the engine system was found through the analysis to be gas leakage during maintenance of the LPG supply line. The technique proposed can be applied to various facilities, such as LPG supply systems, and can be utilized as a standard procedure for risk assessment in developing safety standards for LPG-powered ships.

• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.161-169
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• 2023

Due to the Fourth Industrial Revolution, innovation in various technologies such as artificial intelligence (AI), big data (Big Data), and cloud (Cloud) is accelerating, and data is considered an important asset. With the innovation of these technologies, various efforts are being made to lead technological innovation in the field of defense science and technology. In Korea, the government also announced the "Defense Innovation 4.0 Plan," which consists of five key points and 16 tasks to foster advanced science and technology forces in March 2023. The plan also includes the establishment of a Condition-Based Maintenance system (CBM+) to improve the operability and availability of weapons systems and reduce defense costs. Condition Based Maintenance (CBM) aims to secure the reliability and availability of the weapon system and analyze changes in equipment's state information to identify them as signs of failure and defects, and CBM+ is a concept that adds Remaining Useful Life prediction technology to the existing CBM concept [1]. In order to establish a CBM+ system for the weapon system, sensors are installed and sensor data are required to obtain condition information of the weapon system. In this paper, we propose a sensor data metadata schema to efficiently and effectively manage sensor data collected from sensors installed in various weapons systems.

• Journal of Korean Physical Therapy Science
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• v.31 no.1
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• pp.16-32
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• 2024

Background: Exercise equipments and assistive devices for the disabled are being developed, but improvements for usability are still needed. The purpose of this study was to improve and utilize the developed exercise equipment and assistance devices by conducting usability test for people with spinal cord injury. Design: Cross-sectional Study. Methods: Scenarios and usability indicators were derived by conducting a preliminary usability test, 5 non-disabled men and women aged 19 or older. In the scenario, a total of 9 tasks were sequentially performed, including 2 tasks of entry and exit, 5 tasks of assistance devices and weight stack adjustment, and 2 tasks of pre exercise and exercise. The usability indicators were task success (success or fail), execution time (sec), safety, and convenience. For safety, 7 questions (Likert scale, 1~5 point) related to safety, stability and hazard were derived, and for convenience, the system usability scale (SUS score) was used (range: 0~100, 50 percentile rank is 68 point). Results: As a result of the usability test of people with spinal cord injury, there was a large variation among subjects in the task of adjusting the position of the pulley and support in the execution time (11.64~25.44 seconds), and one person failed to adjust the pulley. The safety level showed a lower score (score = 3 points) than other items in the item of entrapment or skin pressure, and in the case of SUS, the average score was 64.5 points, which was close to the acceptable level. Conclusion: Through the usability test, it was confirmed that exercise equipment for the disabled needs improvement in operability, pinching, and pressure, and that it is necessary to develop an assistive device that provides unrestrained posture information (biofeedback) to maintain correct posture during exercise.

• Journal of Gastric Cancer
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• v.4 no.4
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• pp.219-224
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• 2004

Purpose: Through a survey on an Internet homepage, we conducted research concerning the need of patients and their families for information on gastric cancer. We also assessed their interest in gastric cancer. Materials and Methods: We analyzed 619 inquiries presented from June 2002 to September 2003 and 524 replies submitted to a questionnaire survey delivered by the Internet homepage (www.gastriccancer.co.kr) from August to October 2003 to gastric cancer patients and their families. Results: Analysis of Inquiries: The classified inquiries listed in order of frequency are as follows: treatment, prognosis, stages, symptoms, pathophysiology, diagnostic modalities, favorable food, etiology, follow-up, etc. Among the inquiries about treatment, the most frequent subgroup was about the scope of surgery or perioperative implications. Next came questions concerning chemotherapy. Among the questions from patients yet to be operated, on those about operability and the prognosis were most frequent. Among the patients who had undergone a resection, questions on complications and the corresponding prognosis were most frequent. The concern from patients with inoperable or recurrent cancers was related to terminal care and/or chemotherapy. Analysis of Questionnaires: The respondents acquired information on gastric cancer from the Internet ($40\%$), doctors ($32\%$), the mass media ($15\%$) and acquaintances ($13\%$). Only $6\%$ of the respondents were sufficiently satisfied with the information provided by doctors. Among the respondents, $89.9\%$ were interested in complementing treatment with folk remedies while only $5\%$ were not. Conclusion: Patients and their families were eager to get information about gastric cancer. However, many of them found the doctors' information to be insufficient. Our suggestion is that the public health, academic societies, medical institutions, and public organizations should endeavor to provide through an activated Internet network correct information on gastric cancer. (J Korean Gastric Cancer Assoc 2004;4:219-224)

• Tuberculosis and Respiratory Diseases
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• v.41 no.1
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• pp.26-35
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• 1994

Background: Bronchioloalveolar cell carcinoma today needs further studies as an early diagnosis will drastically improve the chances of cure. Methods: Twenty-four cases of bronchioloalveolar cell carcinoma for the period of 5 years were studied in terms of incidence, age, sex, underlying diseases, symptoms, radiographic findings, methods of diagnosis, clinical and pathologic staging, methods of treatment, and survival retrospectively. Results: No correlation was found between patients' age, sex and underlying diseases. Most common symptoms were cough(62.5%), chest pain(29.2%), and sputum(29.2%). Of the 24 cases, 13 patients(54.2%) had solitary nodule, 6 patients(25%) had multiple nodules. At the time of diagnosis, 3 patients(12.5%) had the stage I diseases, 3 patients(12.5%) had the stage II diseases, 4 patients(16.7%) had the stage IIIa diseases, 3 patients(12.5%) had the stage IIIb diseases, and 11 patients(45.8%) had the stage IV diseases. 14 cases(58.3%) were found inoperable at the time of admission; they all died within 17 months. In 7 cases with stage I, II, IIIa diseases curative resection were attempted, in 1 case with stage IV disease wedge resection for palliative management was performed, and in 4 cases patients were still alive at the time of conclusion of this study. Conclusion: We conclude that early diagnosis of disease will increase operability and improve chances of survival and that aggressive diagnostic workup for suspicious pulmonary infiltrate is essential as early operation offers the best chances of cure.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.320-325
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• 2020

This study aimed to analyze thermo-keeping and economic feasibility by utilizing silica aerogel, which has been attracting attention as a new material, complementing the disadvantages of the conventional multi-layered thermal screen, and producing and installing multi-layered thermal screen. The multi-layered thermal screen used in the experiment was produced in two combinations using a non-woven fabric containing silica aerogel and measured and compared the temperature and fuel consumption changes due to differences in practice with the multi-layered thermal screen being sold and used on the market. Experimental results show that the temperature and relative humidity changes due to the differences of the multi-layered thermal screens in the single-span greenhouse and the multi-span greenhouse were small but remained almost the same temperature and relative humidity. It is judged that this shows that the multi-layered thermal screen using silica aerogel is not inferior to the conventional multi-layered thermal screen. As a result of a comparative analysis of heating energy, the aerogel-based multi-layered thermal screen reduced fuel consumption by about 15% in the single-span greenhouse and about 20% in the multi-span greenhouse compared to the conventional multi-layered thermal screen. It is clear that heating energy is saved as a greenhouse size and duration increase. It was found that the silica aerogel-based multi-layered screen was more breathable and warmer than the conventional multi-layered thermal screen, but It was found that the multi-layered screen used in the multi-span greenhouse was heavier and stiff compared with the conventional multi-layered thermal screen, indicating less workability and operability. Therefore, improvements were applied to the multi-layered screens used in the single-span greenhouses. It was confirmed that the replacement of internal insulation materials reduced thickness and improved stiffness so that there could be sufficient possibility for farmers to use.

• Journal of the Korean Geographical Society
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• v.42 no.1 s.118
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• pp.133-155
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• 2007

The sustainable urban development has emerged as a new paradigm of urban studies in recent years. A review of the literature of land use and transport policies in relation to sustainable development reveals a consensus that the main objectives of sustainable strategy should decrease the numbers and length of journeys, and change the land use pattern towards mixed use and high density. However, there is a lack of empirical research as to what types of policies might influence effectively the reduction in the energy consumption and emission of $CO_2$. in order to sustain urban development. This paper tries to construct the conceptual structure of the PSS(planning support system), which is designed to the simulation of the probable effects of policies and planning of different kinds in cities, and evaluate the sustainablilty level according to construct the structure of the PSS(planning support system), which is designed to the simulation of the probable effects of policies and planning of different kinds in cities, and evaluate the sustainablilty level according to the alternative scenarios. The PSS is composed of three components (input-modeling-output). The core of PSS is integrating land use-transport-environment modeling. The advantages of integrating land use-transport-environment modeling are well known, but there are very few such integrated modeling packages in practice. So this paper tries to apply TRANUS software, which is an integrated land use and transport model. The TRANUS system was calibrated to city of Yongin for the base year. The purpose of the application of TRANUS to Yongin is to examine the operability of TRANUS system in Korea. From the outputs and results of operating the system, TRANUS may be effectively used to evaluate the effects of alternative sustainable urban development policies, since sustainablilty indicators can be extracted from several aspects such as land use consumption, total trips, distance and cost, energy consumption, ratio of transport split.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.2
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• pp.86-93
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• 2016

Performance tests of a 75-tonf liquid rocket engine turbopump were conducted. The performance of sub-components - two pumps and a turbine - and their power matching were measured and examined firstly near the design speed under the LN2 and kerosene environment. In the real propellant - LOX and kerosene - environment tests, design and off-design performance of turbopump were fully verified in regime of the rocket engine operation. During the off-design performance tests, turbopump running time was set longer than the engine operating time to verify the pump operability and set the pump inlet pressure close to design NPSHr to investigate pump suction capability in parallel. It has been found that developed-turbopump satisfied all of the engine required performances.