• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.103-110
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• 2007

An efficient operational strategy using expert system for metro water supply systems in case of emergency situations is developed in this study. The emergency situations of the water supply systems are classified into three categories : pipeline system accident, machinery and electric facility accident and water quality accident. A PC-based expert system is developed using CLIPS for Seoul metro water supply system, Phase 1 & 2 system and Phase 3 & 4 system. Broad professional knowledges and experiences from the experts in the water supply systems have been collected systematically to construct the knowledge base. Decision-making in case of an emergency is based upon the professional knowledge so that a rational and efficient operational management can be available even in the absence of experienced expert. Especially the expert model developed in this study also provides a guide for pumping operation in case of pipeline accident to confirm that the proper pressure to all nodes in the system is supplied. The pipe network simulator KYPIPE has been consecutively executed by trial and error fashion for each pipeline in the system. The results from KYPIPE were included in the knowledge base to supplement the knowledge of the field engineers.

• International Journal of High-Rise Buildings
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• v.9 no.3
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• pp.301-306
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• 2020

In tall building construction, the appropriate control of lifting loads on tower cranes is critical in terms of the construction duration of structural works. The adoption of efficient construction methods can be the most effective way of minimizing the inputs of tower cranes and making a lifting plan and management easier. Based on actual data from a tall building project, this study comparatively analyzes lifting loads of tower cranes by the core structure preceding construction method (CSPCM) and the core structure succeeding construction method (CSSCM). The results revealed that the CSSCM could reduce up to about 56.3% of lifting loads for core works and significantly enhance lifting efficiency compared with the CSPCM. Consequently, this enabled a substantial reduction in the construction duration of structural works. This study provides a practical reference to assist engineers and managers in applying efficient construction methods and lifting equipment operation in tall building projects.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.443-448
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• 2005

Efficient using of the web cache is becoming important factors that decide system management efficiency in the web base system. The cache performance depends heavily on the replacement algorithm which dynamically selects a suitable subset of objects for caching in a finite cache space. In this paper, the web caching algorithm is proposed for the efficient operation of the web base system. The algorithm is designed based on a divided scope that considered size reference characteristic and heterogeneity on web object. With the experiment environment, the algorithm is compared with conservative replacement algorithms, we have confirmed more than $15\%$ of an performance improvement.

• Journal of Distribution Science
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• v.19 no.3
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• pp.25-34
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• 2021

Purpose: The purpose of this study is to analyze the economic ripple effect(ERE) of logistics industry by construction of Trans-Korea Railway (TKR) and present policy measures to minimize the economic loss of South Korea (SK). Research design, data and methodology: As the analysis method, exponential smoothing was used for demand forecasting, Input-Output analysis was used to estimate the economic ripple effect coefficient, and scenario analysis was used to an efficient way to invest in TKR to minimize SK's economic losses. Results: 1) the production(logistics fares) of TKR for 10 years after its completion is about 11.42 trillion won in positive relations, and 26.89 billion won in negative relations. 2) the ERE of SK in positive relations is 24.32 trillion won in production inducement effect, 8.1 trillion won in value-added inducement effect, 3.54 trillion won in import inducement effect, and 70,930 persons in employment inducement effect. But the ERE was insufficient in the negative relations. 3) SK's efficient investment method is providing materials and equipment by SK and building the TKR by North Korea in positive inter-Korea relations. Conclusions: For the successful operation of TKR, international cooperation, legalization and stable peace settlement on the Korean Peninsula are required.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.5
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• pp.81-91
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• 2023

As abnormal weather conditions escalate, water disasters such as droughts and floods occur more frequently. These natural disasters are fatal to agricultural reservoirs, where the operation techniques vary greatly depending on the season and weather conditions, and response through intake works is limited. In response, governments like the Korea Rural Community Corporation have researched efficient water supply methods through irrigation channels. Therefore, previous studies analyzed the irrigation process using numerical models to determine an efficient irrigation system. However, SWMM and EPANET used in previous studies are limited in quantitative agricultural irrigation process analysis. Therefore, this study developed AIRISS to simulate and analyze agricultural irrigation. Specifically, we simulated the irrigation process in the Ssangbong area of South Korea and simulated the irrigation process to verify the performance of the numerical model. AIRISS, developed in this study, is specialized in simulating the agricultural irrigation process. It can check the supply to each paddy and the condition of each paddy.

• Journal of Korea Water Resources Association
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• v.53 no.2
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• pp.89-96
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• 2020

Water management agencies under the Ministry of Environment produce and accumulate qualified basic data for major rivers. However, the integrated management of the river water has been weak since the artificial water circulation process, such as the intaking and drainage of agricultural water, has not been examined in the basin, which includes many agricultural land. In this study, a study was conducted on how the power usage method (operating time method) based on the running time can be applied and improved among indirect flow rate measurement methods used to investigate flow rates collected by the riverside for agricultural water purposes, and thus the resultant data of high reliability can be obtained at low cost. The operation time method is suitable for small-scale water pumping stations where it is difficult to secure real-time power supply data. The reliability of the data was verified through the correlation analysis with the actual flow rate, and it was found that the flow rate calculated by the operation time method reflecting the level of the stream to which the inlet of the pumping station is connected can be reasonably matched with the actual flow rate. In addition, it was confirmed that the investment cost at the time of initial installation of the facility was highly efficient by generating qualified flow data at low cost through comparison with direct flow rate measurement methods. If flow data is secured by applying the operation time method to large and small water farms located along the riverside, it is expected that more quantitative and integrated stream water management will be possible.

• Transactions of the KSME C: Technology and Education
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• v.5 no.2
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• pp.135-143
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• 2017

The domestic unique research reactor, HANARO (Hi-flux Advanced Neutron Application ReactOr), has been constructed with the open-pool, the core is submerged in, for the multi-purpose neutron application. The reactor has a primary cooling system to remove the fission heat from the core and its connected fluidic systems. Since the works are required at the reactor pool top as a characteristic of the research reactor, the radiation shall be minimized with the operation of the hot water layer system to avoid unnecessary radiation exposure on the workers during work at the pool top. Moreover, the pool water management system is connected to the reactor pool to maintain the pool temperature below $50^{\circ}C$ to minimize the uprising radioactive gas or impurity from the colder pool bottom. For the efficient flow rate of the PWMS, the thermal capacity of heat exchanger is selected with 260 kW in the normal operation condition. In this paper, the modeling is formulated to figure out whether or not each pool temperature maintains below the temperature limit and the calculation results show that the designed PWMS heat exchanger has enough capacity with the design margin regardless of the reactor operation mode.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.6
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• pp.523-529
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• 2020

Power distribution management system is essential for the efficient management and operation of power distribution networks. The power distribution system is a system that manages the distribution network based on IT, and has been evolving along with the development of the power industry. The current power distribution system is designed to operate at a relatively low network transmission speed based on the independent operation of the main equipment. However, due to distributed resources such as photovoltaic or energy storage devices, which are rapidly increasing in popularity in recent years, the operation of future distribution environments is becoming more complex, and various information needs to be collected in real time. In this study, the requirements of the next-generation power distribution system were derived to overcome the limitations of the existing power distribution system, and based on this, the communication network system and performance requirements for the distribution system were defined. In order to verify the performance of the designed system, a software-based terminal device simulator was developed because it takes excessive time and cost to introduce a large-scale system such as a power distribution system. Using the simulator, a test environment similar to the actual operation was established, and the number of terminal devices was increased up to 1,000. The proposed system was shown to satisfy the requirements to support the functions of the next-generation power distribution system, recording less than 10 % of the communication network bandwidth.

• Korea Journal of Hospital Management
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• v.7 no.4
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• pp.172-192
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• 2002

The purpose of this study is to ascertain whether the effect of introduction of OCS(Order Communication System) to the hospital is satisfied or not comparing the anticipated effect with the actual effect. For this purpose, a domestic hospital which has introduced and has been operating OCS for several years was chosen. Based on the internal data of S Hospital prepared before introducing OCS, researcher has analyzed the basic direction, design standard and status of operation after the introduction of OCS, etc. After analyzing the status of operations of several departments using OCS and interviewing with the chiefs of pertinent departments, a survey form was designed. Actual survey and interviews were conducted by the researcher for weeks to know whether doctors, nurses, medical technicians and clerks of the patient management dept. were satisfied with OCS and to find if they have any recommendations to improve OCS. Based on the analysis of survey, the effect of OCS was evaluated whether it has satisfied the anticipated effectiveness. For the question if they feel convenient in using OCS, doctors, nursing staffs in charge of ward and the staffs of billing dept. has answered that they were all satisfied(100%). The answers for the same question were relatively high in the case of nurses in charge of outpatient and staffs of radiography. Of course, there have been some nurses and staffs who complained for the inconvenience. However, overall satisfaction was high on the average. Some common problems occurred after the introduction of OCS were frequent errors due to instability of OCS system, paralysis of function of hardware on data back-up system and redundant investment due to erroneous choice of DB program in setting DB. It was also pointed out that lack of computer education and low participation of medical staffs has resulted in failure of developing effective software. As a result, it has lowered the efficiency of OCS. For example, some works have to be done by hands even after OCS. Based on the result of this research, recommendations to maximize the effect of OCS were presented as follows. First, strong leadership of CEO and active cooperation of doctors are mandatory. Second, all the process of hospital work should be analyzed and be redesigned in more efficient ways. Third, OCS should be designed to be user-based system which can be used efficiently by all staffs of the hospital. Forth, prior to the operation of OCS, proper tests of the program and trainings of the pertinent staff are required. Fifth, prior to the selection of hardware, BMT(Bench Marking Test) should be conducted. Sixth, before introducing OCS, staffs in charge of OCS should visit many hospitals operating the OCS system and take their cases into account.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.126-131
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• 2009

A $CO_2$ heat pump system was designed for both cooling and heating in the cabin of electric vehicles, hybrid vehicles or fuel cell vehicles, In this study, the performance characteristics of the heat pump system without any supplementary heating device were analyzed and the heating performance was compared with the cooling performance for various operating conditions. Experiments were carried out by changing the speed of electric drive compressor, the air flow rate of interior heat exchanger and the air inlet temperature and speed of exterior heat exchanger. Therefore, the cooling/heating capacities and the corresponding COPs are quantified. Also, the heat pump system showed an improved performance for the cooling operation and the heating operation. In this study, the experimental results can be used to evaluate the effect of system design changes on system performance as well as the development of a highly efficient heat pump system.