• 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 the Institute of Electronics Engineers of Korea SD
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• v.49 no.5
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• pp.1-9
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• 2012

Memristor which is known as fourth basic circuit element has been developed recently but its electrical characteristics are not still fully understood. Memristor has the incremental and decremental feature of the resistance depending upon the connected polarities. Also, its operational behavior become diverse depending on its connection topologies. In this work, electrical characteristics of diverse types of serial and parallel connections are investigated using the HP $TiO_2$ model. The characteristics are analyzed with pinched hystersis loops on the V-I plane when sine input signal is applied. The results of the work would be utilized usefully for analyzing the characteristics of memristor element and applications to logic circuit and neuron cells.

• Journal of the Korean Society of Costume
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• v.64 no.2
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• pp.113-125
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• 2014

Creative thinking requires an ability to draw ideas on the given topic in a given time period with concentration. For this, the development process of design concept on the topic was collected through experiments and interviews targeting 10 fashion education experts and 10 clothing majors. After the analysis, the results are as follows: First of all, divergent thinking was done to find as many ideas and possibilities as possible at the step of expanding the topic by analogy. This showed characteristics of spreading thoughts through the spread of lexicon to professional field knowledge of learned, individual's cultural background, other art fields. Second, abstracted and designed words that are expanded and listed by the topic analogy were specified the topic gradually through the free combination method between lexicons. The sentences made by the combination of lexicons were interpreted through the serial listing method, in which the connection between sentences had the meaning of orderly cause and effect form, and the parallel listing method that treated information at once. Third, the few characteristics of the procedure that visualizing into the specific design are as follows. Firstly, the method to transform image that lexicon has into the one appropriate to the topic, the case that reflects external characteristics of selected designed word, and the case which reflects as the extrinsic expression of personal immanent and tactic desires. This study has its means to propose methods and directions to help create more creative and systematic ideas by analyzing the characteristics that appeared during the process of thinking language-oriented design.

• Transactions on Electrical and Electronic Materials
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• v.15 no.2
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• pp.103-111
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• 2014

This paper investigates the output powers of PV modules by predicting three unknown parameters: reverse saturation current, and series and shunt resistances. A theoretical model using the non-uniform physical parameters of solar cells, including the temperature coefficients, voltage, current, series and shunt resistances, is proposed to obtain the I-V characteristics of PV modules. The solar irradiation effect is included in the model to improve the accuracy of the output power. Analytical and Newton methods are implemented in MATLAB to calculate a module output. Experimental data of the non-uniform solar cells for both serial and parallel connections are used to extend the implementation of the model based on the I-V equation of the equivalent circuit of the cells and to extend the application of the model to m by n modules configuration. Moreover, the theoretical model incorporates, for the first time, the variations of series and shunt resistances, reverse saturation current and irradiation for easy implementation in real power generation. Finally, this model can be useful in predicting the degradation of a PV system because of evaluating the variations of series and shunt resistances, which are critical in the reliability analysis of PV power generation.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.11
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• pp.763-768
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• 2013

The simulation investigation on the availability with failure density function of major equipment for a sewage treatment plant has been carried out. This study focuses on the availability of the plant and criticality with equipment module induced by component layout and its failure function. The equipment classification of sewage treatment plant and its failure function are established. Also solution methodologies are introduced as Monte-Carlo simulation method and event algorithm for uncertainty problem. The availability in the case of serial connection of equipment with all exponential function is calculated as around 50.4%. In other case of parallel combination with back up equipment, the availability showed over 80.1%. The criticality that a ffects availability showed high value over 77% in the dehydration and concentration process of sludge.

• 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.