• 대한치과보철학회지
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• 제38권2호
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• pp.147-159
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• 2000

The purpose of this study was the evaluation of spectral transmission of the commercial three shade guides and the relationship of hue, value, and chroma according to the transmission rate. The spectral transmittance of three shade guides - Vita Lumin Shade Guide, Vintage and Unibond Shade Guide, and Vitapan 3D-Master Shade Guide - were measured. For direct transmission measurements, each shade tabs were placed at the entrance port of the 1mm diameter intergrating sphere. The intensity of the light source passing through the shade tabs to the right angle was continuously recorded for wavelength from 400 to 700 nm. A transmission spectrum and digital data were obtained for each measurement and they were evaluated using Microcal Origin program. The obtained results of this study were as follows : 1. In Vita Lumin Shade Guide, sum of the transmission rate of the shade tabs at the wavelength 400-700nm was decreased in agreement with the arrangement order at each A, B, C, D group, except D4 shade tab. However, there were no relationships between the transmission rate of the shade tabs and the value-oriented. 2. In Vintage and Unibond Shade Guide, sum of the total transmission rate of the shade tabs was decreased in agreement with the arrangement order at each A, B, C, B group. When all shade tabs arranged in value-oriented, transmission rate was accord with the order, except D4 shade tab. 3. When shade tabs of the Vitapan 3D-Master Shade Guide have the same value and hue, sum of their total transmission rate decreased in accordance with the chroma-oriented. When the shade tabs have the same value and chroma, there were no differences from the order of the transmission rate to the various hue type. However, in the 'R' tabs of reddish hue type, the transmission rate increased at the long wavelength range area. In conclusion, we need the quantitative analyzing instruments in transmission determination. Vitapan 3D-Master Shade Guide covers the tooth color space taking into account the parameters of the systematic value, chroma, hue oriented, and the transmission rate relatively accorded with that sequence.

• 대한수의학회지
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• 제55권2호
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• pp.141-143
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• 2015

Dermatophytosis was found on the right front leg of a 4-month-old female African lion cub (Panthera leo) kept at a zoo with locally marginal alopecia. For diagnosis, culturing on sabouraud dextrose agar was performed and skin scrapings from the lesion were analyzed. The ones from the culture and skin scrapings were identified as Trichophyton mentagrophytes. A zookeeper that had been in contacted with the lion for artificial rearing developed skin lesions with well-defined erythematous plaques on the right arm about 1 month after the lesion in the lion was observed. The ringworm was probably transmitted from the lion through continuous contact.

• Journal of Trauma and Injury
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• 제34권3호
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• pp.212-217
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• 2021

Various medical scenarios have arisen with the prolonged coronavirus disease 2019 (COVID-19) pandemic. In particular, the increasing number of asymptomatic COVID-19 patients has prompted reports of emergency surgical experiences with these patients at regional trauma centers. In this report, we describe an example. A 25-year-old male was admitted to the emergency room after a traffic accident. The patient presented with stuporous mentality, and his vital signs were in the normal range. Lacerations were observed in the left eyebrow area and preauricular area, with hemotympanum in the right ear. Brain computed tomography showed a contusional hemorrhage in the right frontal area and an epidural hematoma in the right temporal area with a compound, comminuted fracture and depressed skull bone. Surgical treatment was planned, and the patient was intubated to prepare for surgery. A blood transfusion was prepared, and a central venous catheter was secured. The initial COVID-19 test administered upon presentation to the emergency room had a positive result, and a confirmatory polymerase chain reaction (PCR) test was administered. The PCR test confirmed a positive result. Emergency surgical treatment was performed because the patient's consciousness gradually deteriorated. The risk of infection was high due to the open and unclean wounds in the skull and brain. We prepared and divided the COVID-19 surgical team, including the patient's transportation team, anesthesia team, and surgical preparation team, for successful surgery without any transmission or morbidity. The patient recovered consciousness after the operation, received close monitoring, and did not show any deterioration due to COVID-19.

• Journal of electromagnetic engineering and science
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• 제11권2호
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• pp.76-82
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• 2011

In this paper, a novel design for a dual-band negative group delay circuit (NGDC) is proposed. Composite right/left-handed (CRLH) ${\lambda}/4$ short stubs are employed as a dual-band resonator. A CRLH ${\lambda}/4$ short stub is composed of a typical transmission line element as the right-handed component and a high-pass lumped element section as the left-handed component. It is possible to simultaneously obtain open impedances at two separate frequencies by the combination of distinctive phase responses of the right/left-handed components. Negative group delay (NGD) can be obtained at two frequencies by using dual-band characteristics of the CRLH stub. In order to achieve a bandwidth extension, the proposed structure consists of a two-stage dual-band NGDC with different center frequencies connected in a cascade. According to the experiment performed, with wide-band code division multiple access (WCDMA) and worldwide interoperability for microwave access (WiMAX), NGDs of $-3.0{\pm}0.4$ ns and $-3.1{\pm}0.5$ ns are obtained at 2.12~2.16 GHz and 3.46~3.54 GHz, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.275-277
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• 1993

It is practically required to develop an optical transmission system, for the diagnosis of electric power apparatus, which enables to distinguish the right signals related to the partial discharge taken place inside the apparatus. These partial discharges are transformed into ultra sonic signals by the sensor and then used for the voltage application to pokels cell. Afterwards, the modulated laser beam is transmitted through the optical fiber. Throughout this work, a laser-beam based detecting system is developed and permits us to reproduce the transmitted signals indirectly without electromagnetic interference. For this purpose the characteristics of this system is well analyzed by means of different type of signals from function generator.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.371-375
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• 2013

The design of a new compact UWB bandpass filter is proposed, which has cascaded center-tapped microstrip composite right/left-handed transmission-line zeroth-order resonators (CRLH-TL ZORs). In an attempt to reduce the size, instead of the conventional half-wavelength resonators or periodic and multiple CRLH-TL cells, only one cell ZOR geometry is adopted as each resonator in the filter. Additionally, two center-tapped ZORs are coupled to increase the slope of the skirt. Besides, stepped impedance matching parts are placed in the paths to the input and output ports to enhance passband and stopband performances. The proposed filter is shown to have the overall size of $0.69{\lambda}_g{\times}0.70{\lambda}_g$, the insertion loss much less than 1 dB, and an acceptable return loss performance in the predicted and measured results.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.784-787
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• 2006

Dual-polarized transmission is one of the effective methods to transmit such a high speed data thanks to two independent channel leads to the orthogonal feature between RHCP (Right-Hand Circular Polarization) and LHCP (Left-Hand Circular Polarization). However, in practical case, the transmitted signal by RHCP polarized antenna in satellite can be occurred at the output port of LHCP polarized antenna in ground station, vice versa. XPD (Cross-Polarization Discrimination) is the ratio of the signal level at the output of a receiving antenna that is nominally co-polarized to the transmitting antenna to the output of a receiving antenna of the same gain but nominally orthogonally polarized to the transmitting antenna. In this paper, the detailed estimation of XPD within the interface between satellite and ground station is written and the influence of XPD to link performance is also described.

• Journal of electromagnetic engineering and science
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• 제13권3호
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• pp.141-150
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• 2013

Multiplexers based on isolation circuits made of metamaterial lines are proposed and studied. The new approach provides unique advantageous features beneficial to system designer. For instance, there is no need to modify the filters used in multiplexers. Also, the design process is straightforward. In this paper, two types of multiplexers based on metamaterial isolation circuits are presented, and their operation concepts are explained. Also, theories and design process of isolation circuits are presented to help readers design and fabricate proposed multiplexers. For verifying the concepts, two types of triplexers and two types of quadruplexers are designed and fabricated. All filters used in the multiplexers are commercial surface acoustic wave filters. The measured results are well matched with the simulation results.

• 전기학회논문지
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• 제57권10호
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• pp.1790-1795
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• 2008

Energy scavenging is a technique that converts ambient energy, for example, vibration and light, to electrical energy in order to supply power to low power electronic devices such as ubiquitous sensors. In this paper, we propose an optimal operation condition of power delivery circuit and design strategy for energy scavenging system in which the generated power is order of microwatt and, consequently, efficient handling of power is critical. We also propose that high data transmission rate is more realistic optimal design objective rather than high energy efficiency. It is shown that disconnection of load from the storage capacitor right after data transmission reduces energy wasting and that optimal value of storage capacitor can be determined at this condition. The feasibility of our propose is proved by experiments and we believe that the proposed design strategy will promote the application of piezoelectric micropower generator to the ubiquitous sensor networks.

• 한국생산제조학회지
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• 제23권4호
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• pp.380-384
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• 2014

This study focused on identifying the major noise source in a tractor cabin using experimental methods. The noise levels in a tractor cabin for different engine revolution speeds were analyzed to identify the noise source. The results showed that the power steering unit (PSU) was the major noise source in a tractor cabin. The PSU was moved to the outside from the inside of the cabin in order to reduce the noise in the tractor cabin. As a result, the noise levels on the left and right sides of the operator in the tractor cabin were reduced by 6.8 and 3.9 dB, respectively. Finally, the window method was introduced to evaluate the contribution of the transmission noise. The orders of significance in the tractor noise were the front, bottom, and left area, successively.