• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.7
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• pp.279-285
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• 2002

This Paper deals with the economical equipment control which is used by internet network system at the industrial workplace. If the control devices can be accessed by internet, we can have the developed possibility of work conditions. in this paper, we presented the advanced digital timer which has a communication function to control and observe panel to realize control solution based on internet to be easily applicable at workplace with low cost, and we used RS-485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet. As the result for experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.2
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• pp.207-213
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• 2004

This paper describes the development of Behind-Tape-Reader (BTR) type DNC system using CYBER 180-830 as a central computer and IBM PC-AT cell control computer and NC lathe with FANUC 5T NC controller. In this system, the connection between central computer and cell control computer is done via RS-232C serial interface board, and that between cell control computer and FANUC 5T controller is done via parallel interface board. The software consists of two module, central computer communication module for NC program downloading and status uploading, NC machine running module for NC operating.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.1
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• pp.251-258
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• 1990

Optimal design of heat exchanger for closed CO$_{2}$ gas turbine plant of three processes selected from the result of cycle analysis have been discussed previously paper(I) has been carried out under specified inlet and outlet conditions. Independent variables such as number of parallel connection, tube diameter, shell side and tube side pressure loss as well as dependent variables such as shell diameter, number of tubes, number of serial connections were all characterized according to the standardization or so. Search method was used to construct a computer simulation together with the calculation of heat transfer rate by logarithmic mean temperature difference method. Strength analysis of major parts was carried to examine their dimensions satisfying heat transfer and pressure loss requirements.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.2
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• pp.196-203
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• 2017

The renewable energy sources can be thought of one of the major measures to reduce greenhouse gas emissions in the industries. However, the utilization technology for those sources is approaching in the different matters. One of them, thermoelectric generation might be applicable to fishing industry. A various of internal combustion engines are used in a wide range of fisheries. After the ignition process, the heat passed out from the exhaust outlet. Recycling the heat could be not only an energy source but also reduction of green gas emission. Therefore, this study was designed to verify the feasibility of generation from wasted exhaust gas and analyze the performance. The designed experiment devices were connected with a data logger and an electric loader to quantify the currency and voltage. The devices were installed in a coastal fishing vessel for a gillnet fishery. During the whole fishing trips, the amount of generation was measured by engine rpm and the fishing operation procedures including vessel operations. At the maximum 1,500 rpm in the practical range, the generation amount was 113.6 W. The amount difference in relation to connection method was within 5 W: serial connection was 111.4 W and parallel connection was 115.8 W.

• Journal of Practical Engineering Education
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• v.9 no.1
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• pp.85-90
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• 2017

The contemporary South Korean landscape is characterised by a massive display of modern apartment buildings. They are omnipresent in their monotonous manifestation and represent the dream of the Korean population. Serial mass housing is a typology that has had a great diffusion all over the world, but how has modern housing developed in South Korea? To this end, what are the resulting local adaptations?. This paper retraces these key evolutional aspects. Methodologically, it draws on a scholarly literature review as well as on-site photographic surveys, developed in connection with an educational program at the Korea Tech University. The result is the analysis of both the urban and architectural transformation from the early modernisation period to the present condition of contemporary housing. A historical background introduces Korean traditional urban houses, to be used as a context to describe the contemporary modern city that has developed since the 1960s. The main emphasis is then placed on the urbanisation process that fully matured during the 1980s together with a focus on the mass housing typology as the main pivot in the urban transformation. Finally, the paper will draw a parallel between modern Western theories and Korean applications.

• Journal of the Korean Chemical Society
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• v.65 no.3
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• pp.219-229
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• 2021

In this study, the new electrochemical cell device using Arduino and sensor was developed, and experiments of changes in voltage at the time of serial and parallel connection of electrochemical cells were conducted to verify the effectiveness of the device. In addition, in order to examine the educational effects of the device, student's inquiry activities of measuring voltage of electrochemical cells and making objects using the voltage difference were conducted. As a result, it was confirmed that the electrochemical device using Arduino and sensor could not only perform automatic measurements and visualize data but also have a possibility to seek various educational effects through easy coding and modification of the device. Based on the results of students' performance, it was found that experimental activities using the device impart a positive effect not only on the understanding of scientific concepts, but also on the development of the practical ability to apply scientific knowledges to the real life. Educational implications are discussed in terms of 'learning by making'.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.511-519
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• 2017

Multi-regional water supply system, which installed for supplying multiple water demands, is characterized by large-sized, long-distance, tree-type layout. This system is vulnerable to long-standing service interruption when a pipe breaks is occurred. In this study, a numerical method is proposed to calculate drainage time that directly affects time of service interruption. To begin with, governing equations are formulated to embed the delayed drainage effect by the friction loss, and to resolve complicated connection of pipelines, which are derived from the continuity and energy equations. The nonlinear hydraulic equations are solved by using explicit time integration method and the Newton-Raphson method. The developed model is verified by comparing the result with analytical solution. Furthermore, the model's applicability is validated by the examples of pipelines in serial, in parallel, and complex layout. Finally, the model is utilized to suggest an appropriate actions to reduce the deviation of draining time in the C transmission line of the B multi-regional water supply system.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.3
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• pp.249-255
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• 2017

This paper presents air-gap control according to Y and Delta connections of a double-sided air-gap permanent magnet synchronous motor (DA-PMSM) with independent three-phase structure. In particular, the DA-PMSM used in this study can be applied to low-speed and high-torque applications, such as wind turbines, tidal power generations, and electric propulsion ships, because of its modular stators and a rotor with numerous permanent magnets. Unlike conventional three-phase machines, the DA-PMSM has a symmetrical configuration with double-sided air-gap. Therefore, Y/Delta winding connections and serial/parallel configurations between stator modules are possible. To identify the DA-PMSM operating characteristics, mathematical modeling is analyzed according to the Y/Delta connections. Moreover, air-gap control performances by applying the winding connection methods are verified through experimental results.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.83-88
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• 2001

This paper deals with the economical equipment control which is used by internet network system at the industrial workplace. If the control devices can be accessed by internet, we can have the developed possibility of work conditions. In this paper, we presented the advanced digital timer which has a communication function to control and observe panel to realize control solution based on internet to be easily applicable at workplace with low cost. and we used 485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet As the result of experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

• Progress in Superconductivity
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• v.3 no.2
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• pp.241-246
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• 2002

We have performed the current and voltage loading tests of resistive superconducting fault current limiters (SFCLS) based on $YBa_2$$Cu_3$$O_{7}$(YBCO) films with the diameter of 2 inch. The SFCL consists of meander-type YBCO stripes covered with 200 nm Au layer grown in situ for current shunt and heat dispersion at hot spots. The minimum quench current of an SFCL unit was about 25 Apeak. Seven SFCL units were connected in parallel fur the current load ing tests at power source of 100 $V_{rms}$ $/2,000A_{rms}$. This SFCL units had maximum limiting current of 170 Apeak during the fault instant and then successfully controlled the fault current below 100 Apeak within 1~2 msec after short circuit. Increased short current also reduced the quench completion time with little change of current limiting characterization. We connected six SFCL units in series fur the voltage loading tests at power source of $1,200 V_{rms}$/170 $A_{rms}$ at this time. The shunt resistors were inserted into each SFCL unit to eliminate power imbalance originated from serial connection of SFCL units. Each SFCL unit was quenched simultaneously during the fault condition. The current increased up to 40 $A_{peak}$ and decreased to 14 $A_{peak}$ after 3 cycles. Quench was completed within 1 msec after the fault. We confirmed operating characteristics of 140 kVA($120 A_{rms}$ $\times$ 1,200 $V_{rms}$) SFCL and presented the manufacturing possibility of 3.3 kV SFCL using 4 inch YBCO films.BCO films.lms.