• Title/Summary/Keyword: Standing Wave

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A Comparative Analysis of Packaging Design of Solar Salts Produced in Korea and Japan (국내산 및 일본산 천일염의 패키징 디자인 비교 분석)

  • Kang, Heesoo;Min, Choonki;Jo, Jungyeon;Shin, Joonsub;Lee, Seeun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.19 no.2
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    • pp.103-108
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    • 2013
  • Packaging of solar salts produced in Korea and Japan were evaluated and compared each other in terms of packaging design such as package types, colors and graphics. The standing pouch type in plastic film was most popular for the Korean salts regardless of the package capacity. But the same type was common only for the lower package capacity of 300 g or less while the plastic film pouch was prevalent for the higher capacity for the Japanese salts. White and brown were dominant colors for the Korean solar salts reminding us of salt farms and the foreshore respectively and strengthening its color identity. White, blue and red were used for the dominant, assort and accent colors respectively for the Japanese salt packaging. Salt farmers and the foreshore are often represented as the main package graphics for the Korean solar salts while the wave symbolising the sea was found frequently for the Japanese ones. The word of 'Shinan' was involved the most in the brand names of the Korean salts and the sea was appeared very often in those of the Japanese ones.

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A Case of Micturition Syncope in a Child (소아에서 발현한 배뇨 후 실신 1례)

  • Lee, Sun Youn;Ryu, Su Jeong;Kim, Deok Soo;Kim, Young Hwue;Ko, Tae Sung;Kim, Jae Moon
    • Clinical and Experimental Pediatrics
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    • v.46 no.12
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    • pp.1274-1278
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    • 2003
  • Syncope in children and adolescents have a common occurrence according for up to 15% before adulthood. Micturition syncope, a kind of situational syncope, can be considered a form of reflex syncope. It can typically occur in healthy young men after rising from bed in the early morning who experience sudden loss of consciousness during or immediately after urination. The mechanism of micturition syncope is not completely understood, but it has been suggested that vasovagal reflex mediated bradycardia and peripheral vasodilation and decreased venous return due to Valsalva effect and standing position lead to the decrease in cerebral blood flow resulting in syncope. The causes of syncope are variable. So complete history taking, physical examination, electrocardiography, exercise stress test, echocardiography, head-up tilt table test, electroencephalography(EEG), brain magnetic resonance image and urodynamic study should be required for the diagnosis of micturition syncope. There were several reports about micturition syncope. However, literature of micturition syncope at the pediatric age has rarely been reported in Korea so far. Therefore, we report a case of a 9-year-old boy with micturition syncope with typical EEG findings of high amplitude delta wave and flattening during syncope.

A Study on Design and Implementation of Low Noise Amplifier for Satellite Digital Audio Broadcasting Receiver (위성 DAB 수신을 위한 저잡음 증폭기의 설계 및 구현에 관한 연구)

  • Jeon, Joong-Sung;You, Jae-Hwan
    • Journal of Navigation and Port Research
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    • v.28 no.3
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    • pp.213-219
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    • 2004
  • In this paper, a LNA(Low Noise Amplifier) has been developed, which is operating at L-band i.e., 1452∼1492 MHz for satellite DAB(Digital Audio Brcadcasting) receiver. The LNA is designed to improve input and output reflection coefficient and VSWR(Voltage Standing Wave Ratio) by balanced amplifier. The LNA consists of low noise amplification stage and gain amplification stage, which make a using of GaAs FET ATF-10136 and VNA-25 respectively, and is fabricated by hybrid method. To supply most suitable voltage and current, active bias circuit is designed Active biasing offers the advantage that variations in $V_P$ and $I_{DSS}$ will not necessitate a change in either the source or drain resistor value for a given bias condition. The active bias network automatically sets $V_{gs}$ for the desired drain voltage and drain current. The LNA is fabricated on FR-4 substrate with RF circuit and bias circuit, and integrated in aluminum housing. As a reults, the characteristics of the LNA implemented more than 32 dB in gain. 0.2 dB in gain flatness. lower than 0.95 dB in noise figure, 1.28 and 1.43 each input and output VSWR, and -13 dBm in $P_{1dB}$.

A Study on the Ultra Small Size 25 Watt High Power Amplifier for Satellite Mobile Communications System at L-Band (L-band 위성통신 시스템을 위한 극소형 25 Watt 고출력증폭기에 관한 연구)

  • Jeon, Joong-Sung;Ye, Byeong-Duck;Kim, Dong-Il
    • Journal of Navigation and Port Research
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    • v.26 no.1
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    • pp.22-27
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    • 2002
  • The 25 Watt hybrid MIC SSPA has been developed in the frequency rang from 1.6265 GHz to 1.6465 GHz for uplink of INMARST's earth station. To simplify the fabrication process, the whole system is designed of two parts composed of a friving amplifier and a power amplifier. The Motorolas MRF-6401 is used for driving part, the Motorolas MRF-16006 and MRF-16030 is used the power amplifier. We reduced weight and volume of high power amplifier through arranging the bias circuits in the same housing. The realized SSPA has more than 30 dB for gain within 20 MHz bandwidth, and the voltage standing wave ratios(VSWR) of input and output port are less than 1.7, respectively. The output power of 44 dBm is achieved at the 1 dB gain compression point of 106365 GHz These results reveal a high power amplifier of 25 Watt which is the design target. The Proposed SSPA manufacture techniques in this paper can be applied to the implementation of high power amplifiers for some radars and SCPC.

Research on the Multi-electrode Plasma Discharge for the Large Area PECVD Processing

  • Lee, Yun-Seong;You, Dae-Ho;Seol, You-Bin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.478-478
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    • 2012
  • Recently, there are many researches in order to increase the deposition rate (D/R) and improve film uniformity and quality in the deposition of microcrystalline silicon thin film. These two factors are the most important issues in the fabrication of the thin film solar cell, and for the purpose of that, several process conditions, including the large area electrode (more than 1.1 X 1.3 (m2)), higher pressure (1 ~ 10 (Torr)), and very high frequency regime (VHF, 40 ~ 100 (MHz)), have been needed. But, in the case of large-area capacitively coupled discharges (CCP) driven at frequencies higher than the usual RF (13.56 (MHz)) frequency, the standing wave and skin effects should be the critical problems for obtaining the good plasma uniformity, and the ion damage on the thin film layer due to the high voltage between the substrate and the bulk plasma might cause the defects which degrade the film quality. In this study, we will propose the new concept of the large-area multi-electrode (a new multi-electrode concept for the large-area plasma source), which consists of a series of electrodes and grounds arranged by turns. The experimental results with this new electrode showed the processing performances of high D/R (1 ~ 2 (nm/sec)), controllable crystallinity (~70% and controllable), and good uniformity (less than 10%) at the conditions of the relatively high frequency of 40 MHz in the large-area electrode of 280 X 540 mm2. And, we also observed the SEM images of the deposited thin film at the conditions of peeling, normal microcrystalline, and powder formation, and discussed the mechanisms of the crystal formation and voids generation in the film in order to try the enhancement of the film quality compared to the cases of normal VHF capacitive discharges. Also, we will discuss the relation between the processing parameters (including gap length between electrode and substrate, operating pressure) and the processing results (D/R and crystallinity) with the process condition map for ${\mu}c$-Si:H formation at a fixed input power and gas flow rate. Finally, we will discuss the potential of the multi-electrode of the 3.5G-class large-area plasma processing (650 X 550 (mm2) to the possibility of the expansion of the new electrode concept to 8G class large-area plasma processing and the additional issues in order to improve the process efficiency.

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Design of Double-Dipole Quasi-Yagi Antenna with 7 dBi gain (7 dBi 이득을 가지는 이중 다이폴 준-야기 안테나 설계)

  • Yeo, Junho;Lee, Jong-Ig;Baek, Woon-Seok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.2
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    • pp.245-252
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    • 2016
  • In this paper, the design of a double-dipole quasi-Yagi antenna (DDQYA) with a gain over 7 dBi at 1.70-2.70 GHz band is studied. The proposed DDQYA consists of two strip dipoles with different lengths and a ground reflector, which are connected trough a coplanar stripline. The length of the second dipole is adjusted to increase the gain in the low frequency band, whereas a rectangular patch director is appended to the DDQYA to enhance the gain in the middle and high frequency band. The effects of the length of the second dipole, and the length and width of the director on the antenna performance are analyzed, and final design parameters to obtain a gain over 7 dBi are obtained. A prototype of the proposed DDQYA is fabricated on an FR4 substrate, and the experimental results show that the antenna has a frequency band of 1.60-2.86 GHz for a VSWR < 2, and measured gain ranges 7.2-7.6 dBi at 1.70-2.70 GHz band.

Study on Factors Affecting Satisfaction with the Life of Elderly with Disabilities (고령장애인의 삶의 만족도 영향요인에 관한 연구)

  • Seo, Ji Hye;Na, Woon Hwan;Jeong, Da Chan
    • 재활복지
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    • v.21 no.4
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    • pp.33-57
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    • 2017
  • The purpose of this study is to analyze factors that can affect the satisfaction with life of elderly with disabilities so as to provide measure for improving the quality of their lives. To that end, elderly with disabilities and 50 years or older were extracted from the raw data (2nd Wave, 1st Survey) of 2016 Panel Survey of Employment for the Disabled (or PSED), conducted by the Ministry of Employment and Labor and the Korea Employment Agency for the Disabled. And they were classified into those aging with disabilities (onset of a disability before 50 years) and those having disabilities with aging (onset of a disability after 50 years). The results of the analysis show factors affecting satisfaction with life were different in the two groups. Although awareness about employment, awareness about disability, levels of happiness, subjective socioeconomic standing, and financial problems were the common factors, health conditions and ability to function in daily life affected more those aging with disability, and employment status was more relevant to those having disability with aging. Based on these results, this study points out the need to take into account awareness about employment and disability when developing services for elderly with disabilities, to solve their financial problems, and to provide a collective approach to employment and health issues in order to improve the quality of their lives.

Cell-cultivable ultrasonic transducer integrated on glass-coverslip (세포 배양 가능한 커버슬립형 초음파 변환자)

  • Keunhyung Lee;Jinhyoung Park
    • The Journal of the Acoustical Society of Korea
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    • v.42 no.5
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    • pp.412-421
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    • 2023
  • Ultrasound brain stimulation is spot-lighted by its capability of inducing brain cell activation in a localized deep brain region and ultimately treating impaired brain function while the efficiency and directivity of neural modulation are highly dependent on types of stimulus waveforms. Therefore, to optimize the types of stimulation parameters, we propose a cell-cultivable ultrasonic transducer having a series stack of a spin-coated polymer piezoelectric element (Poly-vinylidene fluoride-trifluorethylene, PVDF-TrFE) and a parylene insulating layer enhancing output acoustic pressure on a glass-coverslip which is commonly used in culturing cells. Due to the uniformity and high accuracy of stimulus waveform, tens of neuronal cell responses located on the transducer surface can be recorded simultaneously with fluorescence microscopy. By averaging the cell response traces from tens of cells, small changes to the low intensity ultrasound stimulations can be identified. In addition, the reduction of stimulus distortions made by standing wave generated from reflections between the transducers and other strong reflectors can be achieved by placing acoustic absorbers. Through the proposed ultrasound transducer, we could successfully observe the calcium responses induced by low-intensity ultrasound stimulation of 6 MHz, 0.2 MPa in astrocytes cultured on the transducer surface.

Gain Enhancement of Double Dipole Quasi-Yagi Antenna Using Meanderline Array Structure (미앤더라인 배열 구조를 이용한 이중 다이폴 준-야기 안테나의 이득 향상)

  • Junho Yeo;Jong-Ig Lee
    • Journal of Advanced Navigation Technology
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    • v.27 no.4
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    • pp.447-452
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    • 2023
  • In this paper, gain enhancement of a double dipole quasi-Yagi antenna using a meanderline array structure was studied. A 4×1 meanderline array structure consisting of a meanderline conductor- shaped unit cell is located above the second dipole of the double dipole quasi-Yagi antenna. It was designed to have gain over 7 dBi in the frequency range between 1.70 and 2.70 GHz in order to compare the performance with the case using a conventional strip director. As a result of comparison, the average gain of the double dipole quasi-yagi antenna with the proposed meander line array structure was larger compared to the case with the conventional strip director. A double dipole quasi-Yagi antenna using the proposed meanderline array structure was fabricated on an FR4 substrate and its characteristics were compared with the simulation results. Experiment results show that the frequency band for a VSWR less than 2 was 1.55-2.82 GHz, and the frequency band for gain over 7 dBi was measured to be 1.54-2.83 GHz. The frequency bandwidth with gain over 7 dBi increased, and average gain also slightly increased, compared to the conventional case using a strip director.

Classification of Estuaries based on Morphological Convergence (형태적 수렴 특성을 이용한 하구 분류)

  • SHIN, Hyun-jung;RHEW, Hosahng;LEE, Guan-hong
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.3
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    • pp.1-22
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    • 2012
  • The classification scheme of estuaries can be divided into two categories: qualitative classification based on geomorphic characteristics and quantitative classification based upon the physical properties of water body. While simple and intuitive scheme of the former is difficult to quantify, the latter is not easy to apply due to the lack of data. A classification scheme based on morphological convergence is very promising because it only requires easily accessible data such as width and depth of channels, as well as it can characterize estuaries in terms of tidal propagation. Thus, this paper examines the classification scheme based on estuarine morphological convergence using depth and width data obtained from 19 major Korean estuaries. Morphological convergence for each estuary was estimated with the estuarine length, width and depth data to get the convergence parameters, which includes the degree of funneling ${\nu}$ and the dimensionless estuarine length $y_0$. The transfer function ${\xi}({\nu},ky)$ is then deduced analytically from 1D depth-integrated hydrodynamic momentum equation and continuity equation for estuarine shapes. Tidal response of each estuary is finally calculated using ${\nu}$, $y_0$ and ${\xi}({\nu},ky)$ for comparison and classification. The 19 Korean estuaries were classified into three groups: tidal amplitude-dominated estuaries with standing wave-like tidal response (group 1), current-dominated estuaries with progressive wave-like tidal response (group 2), and the intermediate group (group 3) between groups 1 and 2. The sensitivity analysis revealed that uncertainties in determining the estuarine length can have a critical effect upon the results of classification, which indicates that the reasonable determination of the estuarine length is of critical importance. Once the estuarine length is feasibly determined, depth-convergence can be neglected without any negative effect on the classification scheme, which has an important ramification on the wide applicability of the classification scheme.