• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.3-13
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• 2004

The total tug capacity needed for berthing/de-berthing operations of a ship may vary depending on the ship type, size, loading conditions, and environmental circumstances. Traditionally, total tug capacity is determined based on the local guidelines of port authorities or on the rule of thumb. However, the social demands for the enhancement of ship safety at harbor and the economical demands for the cost-effectiveness of tug usage makes it necessary for port authorities to develop more reasonable and detailed guidelines on tug usage which takes various conditions into account. In this paper, the method to estimate the optimum tug capacity of VLCC is suggested by considering various ship conditions such as its size, loading conditions, and environmental circumstances such as wind, wave, tidal currents, and geographical characteristics of a terminal. This method is applied to a VLCC terminal located in Gwang-Yang Harbor of Korea and the results are compared with the local guidelines of the harbor, which shows that there may be a room for the amendment of local guidelines on tug usage.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.799-806
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• 2004

Recently, as the forerunner in establishing the Northeast Asia's logistics base, a lot of marine engineering works such as new ports and container terminals, extension of old ports, new bridges, land reclamation etc. have been progressed. Parallel to it, there is also an increasing demand for improving the safety of construction. In this situation, high resolution seismic reflection profiling can be well used, attempting to classify rocks and sediments under water, if possible, to delineate the distribution of grain sizes in sediments not only for calculating the cost of removing sediments from harbour's channels, but also for estimating the bearing capacities for bridge or port construction. However, the results from the corresponding reflection survey that has been in operation in our country can not be effectively used for engineering purposes mostly due to the insufficient resolution. Thus. in this paper, two innovative strategies are introduced to enhance resolution. The one deals with a newly designed exploration barge that will help reduce several kinds of noises encountered electrically or operationally. The other is associated with an establishment of optimum measuring system comprising e.g. a specially devised hydrophone with a combination of 7 piezoelectric elements. Field experiments performed at Busan harbour are illustrated. The quality of acquired data was thereby fundamentally improved in comparison with that obtained at the same time in a conventional way.

• Journal of Internet Computing and Services
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• v.13 no.1
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• pp.45-55
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• 2012

Electronic data management is getting important to reduce overall cost and run-time of clinical data management with the enhancement of data quality. It also critically needs to meet regulated guidelines for the overall quality and safety of electronic clinical trials. The purpose of this paper is to develop the performance evaluation framework in electronic clinical data management. Four key metrics in the area of infrastructure, intellectual preparation, study implementation and study completion covering major aspects of clinical trial processes are proposed. The performance measures evaluate the extent of regulation compliance, data quality, cost and efficiency of electronic data management process. They also provide measurement indicators for each evaluation items. Based on the key metrics, the performance evaluation framework is developed in three major areas involved in clinical data management - clinical site, monitoring and data coordinating center. As of the initial attempt how to evaluate the extent of electronic data management in clinical trials by Delphi survey, further empirical studies are planned and recommended.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.35-43
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• 2008

Technical trends of propulsion system for small aircraft are investigated. Currently, most small aircraft are equipped with piston engine, turboprop and turbofan engines, and the technology development is going continuously. For piston engines, new diesel engines are arising besides gasoline engine. The diesel engines use relatively low-cost and easy to get fuel(Jet A), so the demand for small aircraft is getting increased, and new engines with high reliability and efficiency are being developed. For gas turbine engines, application of small turbofan is getting increased for newly arising VLJ market and the engine demand will be rapidly increased in the future. On the other hand, some electric propulsions without fossil fuels are being developed without high cost of fuel and environmental effects. In the future, propulsion system for small aircraft will be developed having enhancement of performance and efficiency with higher reliability and safety.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.4
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• pp.442-451
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• 2019

Objectives: The aim of this study was to review the reduction methods for ammonia (NH₃) and hydrogen sulfide (H₂S) exposure in livestock. Methods: By reviewing domestic and international research reports from Korea and China, reducing ammonia and hydrogen sulfide in livestock pens was analyzed in terms of ventilation, deodorant, and feed additives. In addition, exposure limits in Korea and China were examined through a comparison between 'TLV-TWA and STEL under the Industrial Safety and Health Act in Korea' and 'Management Standards for Air of Livestock Pens in China'. Results and Discussion: In order to effectively control hazardous gases and odors in livestock pens, the enhancement of natural ventilation or the addition of ventilation fans at the pollution source are being examined. Deodorants are used as adsorbents or masking deodorants. Additives to feed were zeolite powder, FeSO₄·7H₂O, enzymes, and microbial preparations. Use of feed additives was low-cost and had significant effects compared to other methods. Zeolite was the most commonly used in feed additive in Chinese cases and proved to be low-cost and effective for reducing harmful gases. Enzyme preparations were shown to stimulate the growth of livestock, but were expensive. Conclusions: This study reviewed and examined domestic and international research papers in Korea and China for reducing ammonia and hydrogen sulfide concentrations in livestock pens. More diverse research and the development of feed additives are needed.

• Journal of radiological science and technology
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• v.47 no.2
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• pp.107-116
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• 2024

In this study, we analyzed the use of general radiography imaging and effective dose in inpatients. Our aim is to help reduce national medical radiation exposure doses and develop rational health-care financial policies. The effective dose for each general radiography was calculated using the ALARA-GR program for 53 types (total: 260 codes) general radiography codes selected from 'National Health Insurance Care Benefit Cost'. The usage of general radiography was analyzed in the 2018 inpatient patient data of the Health Insurance Review and Assessment Service, and the effective dose for each general radiography was analyzed. 89.00% of inpatients undergo general radiography imaging at least once, with an average of 12.63 scans per person and an effective dose of 1.00 mSv. Those who received support from Medical Aid showed a higher value compared to those who were insured by National Health Insurance, with 17.39 cases and 1.43 mSv (p<.001). Chest had the highest usage rate at 23.12% for general radiography imaging, while L-spine had the highest effective dose at 24.53%. It is estimated that 420 inpatients patients undergo 121 to 820 general radiography imaging procedures per year, and 233 inpatients are estimated to have an annual effective dose of >20.00~58.25 mSv. Rational use of health-care finances and the practice of medical radiation safety management are essential for the well-being of individuals, the enhancement of quality of life, and the improvement of health-care quality.

• The Journal of Korean Medicine
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• v.33 no.4
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• pp.17-25
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• 2012

Objectives: This study was conducted to explore the contemporary perception of traditional Korean medical doctors (TKMDs) on traditional Korean medicine (TKM) policies and issues. Methods: A questionnaire that included traditional medicine policy- and treatment-related issues was sent to 130 TKM medical centers and 4,300 TKM local clinical offices in Korea, and received responses from total 648 TKMDs in 122 TKM medical centers and 465 TKM local clinical offices. Results: Of the responding TKMDs, 40% believed that unification of Western and traditional medicines would benefit both modes of medical treatment, 67.6% were against allowing Chinese doctor certification to be effective in Korea through the Korea-China FTA (Free Trade Agreement), and 57.8% believed that the number of TKMDs should be reduced. We also found that 46.1% of TKMDs believed that more lectures on Western medicine would be needed in schools of TKM. Moreover, 87.5% of respondents regarded medical knowledge as necessary for treatment, and 49.4% believed National Certification Commission for Acupuncture and Traditional Medicine (NCCAOM) would be not necessary. TKMDs regarded governmental efforts as more vital than education in schools or individual efforts for enhancement of the traditional medical care market in Korea. To efficiently provide the advantages of complementary CAM, such as cost and safety, detailed research is required when policy is made. Conclusions: The TKM industry must implement policies how the relationship with Western medicine can be better defined under the current dual medical system. On the issue of human resources, more research will be needed on the current policy, which serves to maintain the status quo by blocking the importation of Chinese practitioners and by reducing the number of new practitioners.

• Journal of Construction Engineering and Project Management
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• v.9 no.3
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• pp.1-21
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• 2019

The management of mega construction projects which incorporate a large number of stakeholders, technologies, data, work culture etc., is cumbersome. The experts in the construction arena advocate that interface management serves as a precise tool in resolving these conflict points due to the intricate nature of the construction projects. Interface management is a current trending management practice in the construction industry which is also a beneficiary to mega/fast track projects in enhancing the project performance. The main objective of this study is to validate a model for assessing the relationships among interface management, IT applications, project performance & project benefits. The mediating effect of interface management in relationship between project performance & interfacial factors was also investigated. The research model was validated using PLS-SEM (Partial Least Square-Structural Equation Modelling) approach. Data were collected from clients, contractors, consultants in large scale projects through questionnaire survey and smart-PLS software was used to analyse the conceptual model. The research model comprises eleven hypothesis and the significance of these hypothesis were tested using T- statistics values. The research implies that people/participants factor is greatly influenced by interface management with the path coefficient of 0.608 and also enhancement of project's schedule performance due to the interface management is strongly appealing (Path coefficient = 0.711). The results also reveal IT application is significantly associated with interface management practice (Path coefficient =0.723) and also the effect of IT application on project performance (schedule, cost, quality & safety) is successfully mediated through interface management practice. The practical application of this validated model was done through case study. The case study aims at measuring the impact of interface management on interfacial factors and role of interface management in improving the project performance in the construction organisations.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.196-205
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• 2019

Ni-rich layered oxides $Li(Ni_xCo_yMn_z)O_2$ (x + y + z = 1) have been extensively studied in recent times owing to their high capacity and low cost and can possibly replace $LiCoO_2$ in the near future. However, these layered oxides suffer from problems related to the capacity fading, thermal stability, and safety at high voltages. In this study, we use surface coating as a strategy to improve the thermal stability at higher voltages. The uniform and conformal $Al_2O_3$ coating on prefabricated electrodes using atomic layer deposition significantly prevented surface degradation over prolonged cycling. Initial capacity of 190, 199, 188 and $166mAh\;g^{-1}$ is obtained for pristine, 2, 5 and 10 cycles of ALD coated samples at 0.2C and maintains 145, 158, 151 and $130mAh\;g^{-1}$ for high current rate of 2C in room temperature. The two-cycle $Al_2O_3$ modified cathode retained 75% of its capacity after 500 cycles at 5C with 0.05% capacity decay per cycle, compared with 46.5% retention for a pristine electrode, at an elevated temperature. Despite the insulating nature of the $Al_2O_3$ coating, a thin layer is sufficient to improve the capacity retention at a high temperature. The $Al_2O_3$ coating can prevent the detrimental surface reactions at a high temperature. Thus, the morphology of the active material is well-maintained even after extensive cycling, whereas the bare electrode undergoes severe degradation.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.1-8
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• 2013

This study focuses on a ship detection and tracking method using Frequency Modulated Continuous Wave (FMCW) radar used for horizontal surveillance. In general, FMCW radar can play an important role in maritime surveillance, because it has many advantages such as low warm-up time, low power consumption, and its all weather performance. In this paper, we introduce an effective method for data and signal processing of ship's detecting and tracking using the X-band radar. Ships information was extracted using an image-based processing method such as the land masking and morphological filtering with a threshold for a cycle data merged from raw data (spoke data). After that, ships was tracked using search-window that is ship's expected rectangle area in the next frame considering expected maximum speed (19 kts) and interval time (5 sec). By using this method, the tracking results for most of the moving object tracking was successful and those results were compared with AIS (Automatic Identification System) for ships position. Therefore, it can be said that the practical application of this detection and tracking method using FMCW radar improve the maritime safety as well as expand the surveillance coverage cost-effectively. Algorithm improvements are required for an enhancement of small ship detection and tracking technique in the future.