• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.5
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• pp.1026-1031
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• 2003

Automatic feed pumps are operated and stopped by a pressure switch. Thus, because of repeated operations and stops of the pumps according to fluctuations of water volume, operation with constant rate and pressure is impossible. Moreover, because of repeated running of the pump, keeping up of constant pressure is impossible and damage and energy loss are weak points of the pimps. To make up for defects of an automatic feed pump, this paper designed and made a static pressure feed system which was composed of a feed water control valve, a flow sensor and a control system. The valve device plays an important part in reducing load of pumps by constant water supply regardless of outflow of water. Outflow of water is determined by infrared diode of the flow sensor. The control system is made of a 8 bit micro-processor and the pump was controled by a specific control algorithm. With the constant pressure feed system, discharge pressure was kept at fixed pressure, accurate operations and stops were smoothly accomplished and the pump was operated with constant pressure. Thus, the constant pressure feed system can be considered as an advanced system which made up for the weak points in the current automatic feed systems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.423-428
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• 2005

Due to the fast growing rate of the global container trade, every major port is under the pressure of meeting the projected capacity demand. As a result, alternative solutions have been sought for improving capacity and meeting the growing demand for container storage area and terminal capacity. Moreover, material handling process re-engineering is now a critical issue for logistics and supply chain managers of airline, shipping lines, terminal and warehousing enterprises around the world. Therefore, the purpose of this paper is to develop the 3D simulator for executing performance valuation of port transportation systems. The developed 3D simulator system is to measure the effectiveness of the proposed total system and compare it with existing practices. The performance analysis variables are also defined for these comparisons.

• Journal of Navigation and Port Research
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• v.44 no.2
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• pp.88-97
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• 2020

In the past 20 years, passenger and cargo transportation performance at the international passenger ports in Korea have increased by 8.6% on the compound annual growth rate, respectively. The Korean government had expected to continue expanding the market of car ferries and the government included plans for the development of additional routes and lanes with neighboring countries such as China, J apan, and Russia as a part of the Plan of the Korean Ministry of Oceans and Fisheries in 2019. However, compared to the development of routes, the management and operation of passenger terminals are inefficient. The purpose of this paper was to introduce the overall improvement of the passenger terminal operating system that reflects the recent changes in the supply and demand of international passenger vessels and the needs of the government and private sector passengers. To this end, a basic survey was conducted on the status of operations and facilities at the Busan International P assenger Terminal and a questionnaire survey was administered on the subject of use. The results of the survey were analyzed using the IPA model. As a result of the analysis, three items in the operation sector, three items in the facility sector, and four items in the system sector of the Busan International Passenger Terminal were identified as in need of improvement. Based on the results, the need for investment to improve the international passenger terminal operating system is suggested.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.138-141
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• 2015

K-water operates many Water Treatment Plants(WTP) to supply clean water to people. There are automation process control equipments collecting data at each step in WTP. The data collected is big enough to 370,000Tag/min from the K-water Water Treatment Plants. In the past, this big data was not important, we focused on the operating water purification process using the data. Currently, we increased the importance of attention to take advantage of Big Data. The research about the accident reduction and efficiency improvement in WTP are ongoing by data collection and analysis. In this paper, we analyzed the flow rate, power and pressure obtained in the accident case in WTP. We researched the methods for accident prediction and reduction.

• Journal of the Korean Geographical Society
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• v.51 no.1
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• pp.41-56
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• 2016

This study investigates the employment and spatial mismatch as a significant acting factor of deepening urban poverty and analyses the placeness of regional labor market that the more efficient place-based labor market intervention needs to take into account. The change of unemployment rate as a regional labor market outcome in metropolitan cities is determined by the dynamic interaction between disequilibrium of labor supply and demand and employment mismatch according to various labor market conditions and its process is certainly differentiated across the metropolitan regional labor markets. In addition, it is analyzed that during the employment suburbanization the spatial mismatch puts differentiated impacts on different labor groups through human capital requirements and industry-selective job opportunities. As a result, because this whole process works with its unique process within individual regional labor markets, in order to link between urban poverty and employment mismatch and to promote problem-solving labor market intervention, we need to develop place-based policy based on the placeness of regional labor marekt.

• Journal of Hydrogen and New Energy
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• v.23 no.6
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• pp.598-603
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• 2012

Despite the high efficiency and eco-friendly of Household Fuel Cell System it has hardly obtained popularity mainly due to its high prices. In order to encourage use of the system prices and operational expenses need to become economical. In this study, optimization through simulation was conducted to find out the optimal operational condition. As a result of simulation the system is operated with DSS operation from 5 O'clock to 19 O'clock for 14 hours at the constant output of 0.4kW to maximize reduction of energy rate. this DSS operation condition can reduce 200,000 won of energy rates in 35 pyoung apartment for a year. And, we can know that starting time of DSS operation don't effect to energy rates through the simulation. Furthermore, the household fuel cell system with the rated output of 1kW should be reduced to 0.4 - 0.6kW which can promote installation of household Fuel Cell System. Now, the household fuel cell system don't have been used widely due to economical efficiency. but, in the near future, Fuel Cell will be used to household by decrease of LNG price caused by development of shale gas.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.11
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• pp.48-55
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• 2009

This paper presents a high-speed Forward Error Correction (FEC) architecture based on three-parallel Reed-Solomon (RS) decoder for next-generation 100-Gb/s optical communication systems. A high-speed three-parallel RS(255,239) decoder has been designed and the derived structure can also be applied to implement the 100-Gb/s RS-FEC architecture. The proposed 100-Gb/s RS-FEC has been implemented with 0.13-${\mu}m$ CMOS standard cell technology in a supply voltage of 1.2V. The implementation results show that 16-Ch. RS-FEC architecture can operate at a clock frequency of 300MHz and has a throughput of 115-Gb/s for 0.13-${\mu}m$ CMOS technology. As a result, the proposed three-parallel RS-FEC architecture has a much higher data processing rate and low hardware complexity compared with the conventional two-parallel, three-parallel and serial RS-FEC architectures.

• Journal of Environmental Science International
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• v.25 no.11
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• pp.1467-1474
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• 2016

In response to the water shortage problem, continued attempts are being made to secure consistent and reliable water sources. Among various solutions to this problem, wastewater effluent is an easy way to secure the necessary supply, since its annual output is consistent. Furthermore, wastewater effluent has the advantage of being able to serve various purposes, such as cleaning, sprinkling, landscaping, river management, irrigation, and industrial applications. Therefore, this study presents the possible use of reclaimed industrial wastewater treated with Birm filters and a UF membrane, along with an analysis on membrane fouling. The preprocessing stage, part of the reclamation process, used Birm filters to minimize membrane fouling. Since this study did not consider heavy metal levels in the treated water, the analyses did not include the criterion for irrigation water quality. However, the wastewater reclaimed by using Birm filters and a UF membrane met every other requirement for reclaimed water quality standards. This indicated that the treated water could be used for cleaning, channel flow for maintenance, recreational purposes, and industrial applications. The analysis on the fouling of the Birm filter and UF membrane required the study of the composition and recovery rate of the membrane. According to SEM and EDX analyses of the UF membrane, carbon and oxygen ion composition amounted to approximately 57%, whereas inorganic matter was not detected. Furthermore, the difference in the recovery rates of the distressed membrane between acidic and alkaline cleaning was more than ~78%, which indicated that organic rather than inorganic matter contributed to membrane fouling.

• Journal of Aquaculture
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• v.20 no.3
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• pp.178-183
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• 2007

We investigated the effect of salinity decrease, food supply and color of the rearing tank on the growth and survival of Amphiprion polymnus larvae. White tanks had the highest survival rate, followed by transparency, black and blue tanks(P<0.05). The transparency tank had the best growth, followed by black tank, white and blue tanks(P<0.05). Daily food intakes of larvae with $5.1{\sim}10.0mm$ in total length were $36.8{\sim}429.3$ Artemia nauplii. When salinity was lowered 5 psu per week from 32 psu, all the larvae died under salinity condition 17 psu. In lowered 2 psu per 3 days, its all died at 16 psu.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.8 s.338
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• pp.1-6
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• 2005

A dual-level low voltage differential signalling (DLVDS) circuit is proposed aiming at reducing transmission lines for LCD driver IC. In the proposed circuit, we apply a couple of primitive data to DLVDS circuit as inputs. The transmitter converts two inputs to two kinds of fully differential level signals. In this circuit, two transmission lines are sufficient to transfer two primitive inputs while keeping the LVDS feature. The receiver recovers The original input data through a level decoding circuit. We fabricated the proposed circuit using $0.25\mu m$ CMOS technology. The resultant circuit shows 1-Gbps/2-line data rate and 35-mW power consumption at 2.5V supply voltage, respectively.