• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.257-259
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• 2002

In investigating the characteristics of a neural network, the use of planar microelectrode array shows several advantages over normal intracellular recording[1]. A transparent indium tin oxide(ITO) multi-electrode array(MEA) was fabricated and its top surface was insulated with photodefinable polyimide(HD-8001) except the exposed area for interfacing between the ITO electrodes and the neuronal cells. The exposed ITO electrodes were platinized in order to reduce the impedance between the electrodes and electrolyte. The one-minute platinization with $0.99nA/{\mu}m^2$ current density reduced the average impedance of the electrodes from $2.5M\Omega\;to\;90k\Omega$ at 1kHz in normal ringer solution. Cardiac cells were cultured on this MEA as a pilot study before neuron culture. The signals detected by the platinized electrodes had larger amplitudes and improved signal to noise ratio(SNR) compared to non-platinized electrodes. It is clear that microelectrodes need to have lower impedance to make reliable extracellular recordings, and thus platinization is essential part of MEA fabrication. Burst spike of cultured olfactory bulb was also detected with the MEA having platinized electrodes.

• Journal of the Korean Society of Physical Medicine
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• v.19 no.2
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• pp.107-122
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• 2024

PURPOSE: This study examined sports injuries among national sitting volleyball players and to provide baseline data for the development of programs to prevent injuries and enhance performance. METHODS: The study surveyed 21 national team athletes (12 males and nine females) participating in the 4^th Hangzhou Asian Para Games. The questionnaire consisted of 17 items, including general information, type of disability, sites and types of sports injuries and their causes, the current state of sports injuries and the treatment and management of injuries. RESULTS: The survey results suggested that the most common injury sites were the finger, shoulder, and waist. The most frequent types of injuries were sprain, muscle cramp, and LBP. The causes were insufficient warm-up, playing unhealed and carelessness. Injuries were most prevalent during morning training and in the winter. Most injuries occurred in practice, and the actions most likely to cause injuries were blocking, spike and sitting movements. Ice and spray were the most common treatments, usually administered by the athletes themselves. Physical therapy was the most common post-injury management, and the most common sequelae involved continuing to use despite pain. CONCLUSION: Based on these results, systematic and individualized training and therapeutic support tailored to the characteristics of sitting volleyball and the types of disabilities are necessary to prevent and manage sports injuries among national players. Continuous injury management by medical staff, particularly physical therapists, is essential to maintain the health of disabled athletes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.461-468
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• 2010

This paper presents a simple digital LCD backlight inverter using a single-chip microcontroller. The proposed inverter reduces the ignition voltage and eliminates the current spikes and hence improves the ignition behavior of the cold cathode fluorescent lamp(CCFL). Thus it increases the CCFL's life span. This is achieved by implementing a digital dimming control algorithm, that contains the soft-starting algorithm, all on a single-chip microcontroller. The inverter utilizes the full-bridge resonant circuit topology. The design example along with a simple analysis for the inverter is shown, and the experimental results of the designed prototype results in close agreement with the theoretical analysis and explanation. The overall system's power efficiency is approximately 85%. Compared with conventional inverters, the ignition voltage is reduced by around 30% without any lamp current spike occurring during the dimming control operation.

• Korean Journal of Plant Taxonomy
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• v.32 no.3
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• pp.301-338
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• 2002

Morphological characters of sections Rhomboidales (four taxa) and Digitatae (seven taxa) of the subgen. Eucarex (genus Carex, Cyperaceae) were reexamined. The epidermal patterns of perigynium, achene and leaf were investigated by SEM and LM. Morphological characters such as length and width of stem, leaf, bract, spike, scale, perigynium and achene, and shape of cross-sectioned stem, spike, scale, apex of scale, perigynium, beak and base of perigynium, achene, hair present or absent in perigynium, number of involucre and epidermal pattern of perigynium, achene and leaf(shape of fundamental epidermal cell and cell wall, type of silica body, shape of beak epidermal cell and cell wall in perigynium, subsidiary cell shape, size and frequency of stomatal complex of leaf) were useful for the identification of the observed 11 taxa. According to the current study, examined 11 taxa of sections Rhomboidales and Digitatae were distinct from each other regarding by length of leaf, stem, pistillate scale and perigynium, shape and epidermal cell of perigynium beak. C. lanceolata and C. humilis have been confused due to similar morphological characters. C. lanceolata and C. humilis were distinct, however with respect to from length of stem, leaf ligule present or absent, shape of cross-sectioned stem, epidermal patterns of perigynium, achene and leaf. And C. lanceolata could be distinguished from C. pediformis by shape of perigynium and achene, shape of cross-sectioned of stem, epidermal pattern of perigynium, achene and leaf.

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.188-199
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• 2019

In this study, research trends were investigated by examining important academic research on museum lighting that has been carried out in Korea over the past 30 years. The aim was to highlight important studies conducted in Korea on material deterioration caused by museum lighting and to examine the current status of research on LED light sources to provide direction for future research. The ultimate goal of studies on museum lighting is to improve the long-term conservation effects, and this study examined the latest light sources of each era. Prior to the 1990s, the effects of light sources on relics were assessed by investigating incandescent light bulbs and fluorescent lamps, the first museum exhibition lighting. Then in the 1990s, the introduction of halogen lamps and HID lamps led to the analysis of the characteristics of a light source itself and the introduction of illumination standards. In the 2000s, the lighting environment of museums was investigated based on the characteristics of the light sources that had been studied, and in terms of preservation, research was conducted not only to improve the conservation of relics but also to improve the sentiments of visitors. After 2010, LED lamps were introduced; therefore, material deterioration studies on LED lamps were expanded. During this period, enhancements to LED light sources were made, such as reducing the blue spike area and increasing color rendering. With the development of lighting used in museums and art galleries, the direction of the display preservation criteria has led to the need to prepare advanced standards, covering all aspects from the center of illumination to the consideration of the color of an object and the speed of radiation from the light source. Regular studies of museum lighting in a long-term perspective should be planned to standardize the more advanced conditions of material discoloration.

• Journal of IKEEE
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• v.26 no.4
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• pp.633-638
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• 2022

Rencently, neuromorphic systems of spiking neural networks (SNNs) that imitate the human brain have attracted attention. Neuromorphic technology has the advantage of high speed and low power consumption in cognitive applications and processing. Resistive random-access memory (RRAM) for SNNs are the most efficient structure for parallel calculation and perform the gradual switching operation of spike-timing-dependent plasticity (STDP). RRAM as synaptic device operation has low-power processing and expresses various memory states. However, the integration of RRAM device causes high switching voltage and current, resulting in high power consumption. To reduce the operation voltage of the RRAM, it is important to develop new materials of the switching layer and metal electrode. This study suggested a optimized new structure that is the Metal/Al₂O₃/HfO_x/SWCNTs/N+silicon (MOCS) with single-walled carbon nanotubes (SWCNTs), which have excellent electrical and mechanical properties in order to lower the switching voltage. Therefore, we show an improvement in the gradual switching behavior and low-power I/V curve of SWCNTs-based memristors.

• IMMUNE NETWORK
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• v.21 no.6
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• pp.38.1-38.8
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• 2021

Recently, a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (B.1.1.529) Omicron variant originated from South Africa in the middle of November 2021. SARS-CoV-2 is also called coronavirus disease 2019 (COVID-19) since SARS-CoV-2 is the causative agent of COVID-19. Several studies already suggested that the SARS-CoV-2 Omicron variant would be the fastest transmissible variant compared to the previous 10 SARS-CoV-2 variants of concern, interest, and alert. Few clinical studies reported the high transmissibility of the Omicron variant but there is insufficient time to perform actual experiments to prove it, since the spread is so fast. We analyzed the SARS-CoV-2 Omicron variant, which revealed a very high rate of mutation at amino acid residues that interact with angiostatin-converting enzyme 2. The mutation rate of COVID-19 is faster than what we prepared vaccine program, antibody therapy, lockdown, and quarantine against COVID-19 so far. Thus, it is necessary to find better strategies to overcome the current crisis of COVID-19 pandemic.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.108-116
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• 2002

This paper presents the measurements and evaluation of voltage waveforms due to human electrostatic discharge(ESD). The principle of operation and design rule of a new device for measuring the ESD fast transient voltages with very fast rise time were described. Peak values and rise time of ESD voltages derived from a charged human body under a variety of experimental conditions were examined. The frequency bandwidth of the proposed voltage measuring system ranges from DC to 400[㎒]. The ESD voltage waveform is nearly equal to the ESD current waveform and the peak amplitude of ESD current waveform is roughly proportional to the ESD voltage in each experimental conditions. A rapid approach results in a discharge voltage with a faster initial rise time than for a slow approach. The voltages caused by direct finger ESDs have an initial slope with a relatively long, 10∼30[ns] rise time, but the amplitude is small. On the other hand, the voltages caused by direct hand/metal ESDs have a steep initial s1ope with 1 ∼3[ns] rise time, but an initial spike is very big. As a consequence, it was found that the ESD voltage and current waveforms strongly depend on the approach speed and material of intruder. These measurement results would be useful to design the ESD protective devices.

• Journal of the Korea Furniture Society
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• v.23 no.2
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• pp.122-129
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• 2012

This article was intended as fundamental materials to recognize the current status of furniture hard ware in Korean market and to fix the identity of Korean furniture, by investigating and comparing the furniture hard ware used in the Joseon era and in modern times by type, function, shape and material. The analysis of furniture hard ware of the Joseon era and modern times from the view of functional aspects was oriented to the hard ware necessary to open and close the door & drawer on one side, and to that being attached to the main body of furniture not to scratch the wood by another wood on the other side, and from this the following conclusion was drawn. First of all, "Gwangdoojung" - a kind of spike- and metal decoration on the edge of the furniture disappeared, while the function-oriented hard wares have been diversified in modern times, from the perspective of the change of kinds. Second, the functional aspect of the furniture hard ware was emphasized in modern times than the Joseon era. In other words, the hard wares of the Joseon era came into view due to their strong appeal to decoration, whereas those of modern times were mostly hidden or moderated, keeping the function substantially. Third, the hard wares from the Joseon era were shown in concrete and detailed shape motivated by natural objects and furthermore even gloriously, but the modern hard wares are simple & basic geometry, from a formative point of view. Fourth, the material aspects present that the Joseon era's hard ware was mainly cast iron, whereas that of modern times shows the diversification from metal to even plastic. Finally, the recent trend in naming of the hard wares is the words of foreign origin. This resulted from that the foreign names of hard wares are valid also after import process in Korean market, so the domestic development of hard ware as the essential factor for the furniture design is urgently necessary to establish the identity of Korean modern furniture.

• Korean Journal of Materials Research
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• v.13 no.1
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• pp.43-47
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• 2003

As and BF$_2$dopants are implanted for the formation of source/drain with dose of 1${\times}$10$^{15}$ ions/$\textrm{cm}^2$∼5${\times}$10$^{15}$ ions/$\textrm{cm}^2$ then formed cobalt disilicide with Co/Ti deposition and doubly rapid thermal annealing. Appropriate ion implantation and cobalt salicide process are employed to meet the sub-0.13 $\mu\textrm{m}$ CMOS devices. We investigated the process results of sheet resistance, dopant redistribution, and surface-interface microstructure with a four-point probe, a secondary ion mass spectroscope(SIMS), a scanning probe microscope (SPM), and a cross sectional transmission electron microscope(TEM), respectively. Sheet resistance increased to 8%∼12% as dose increased in $CoSi_2$$n^{＋}$ and $CoSi_2$$p^{V}$ , while sheet resistance uniformity showed very little variation. SIMS depth profiling revealed that the diffusion of As and B was enhanced as dose increased in $CoSi_2$$n^{＋}$ and $CoSi_2$$p^{＋}$ . The surface roughness of root mean square(RMS) values measured by a SPM decreased as dose increased in $CoSi_2$$n^{＋}$ , while little variation was observed in $CoSi_2$$p^{＋}$ . Cross sectional TEM images showed that the spikes of 30 nm∼50 nm-depth were formed at the interfaces of $CoSi_2$$n^{＋}$ / and $CoSi_2$/$p^{＋}$, which indicate the possible leakage current source. Our result implied that Co/Ti cobalt salicide was compatible with high dose sub-0.13$\mu\textrm{m}$ process.