• Title/Summary/Keyword: Wave characteristics

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Vegetation Water Status Monitoring around China and Mongolia Desert using Satellite Data (위성자료를 이용한 중국과 몽골 사막주변의 식생수분상태 모니터링)

  • Lee, Ga-Lam;Kim, Young-Seup;Han, Kyoung-Soo;Lee, Chang-Suk;Yeom, Jong-Min
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.4
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    • pp.94-100
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    • 2008
  • Recently, global warming for climate system is a crucial issue over the world and it brings about severe climate change, abnormal temperature, a downpour, a drought, and so on. Especially, a drought over the earth surface accelerates desertification which has been advanced over the several years mainly originated from a climatic change. The objective of this study is to detect variation of vegetation water condition around China and Mongolia desert by using satellite data having advantage in observing surface biological system. In this study, we use SPOT/VEGETATION satellite image to calculate NDWI (Normalized Difference Water Index) around study area desert for monitoring of status of vegetation characteristics. The vegetation water status index from remotely sensing data is related to desertification since dry vegetation is apt to desertify. We can infer vegetation water status using NDWI acquired by NIR (Near infrared) and SWIR (Short wave infrared) bands from SPOT/VGT. The consequence is that NDWI decreased around desert from 1999 to 2006. The areas that NDWI was decreased are located in the northeast of Mongolian Gobi desert and the southeast of China Taklamakan desert.

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Differentiation of Vocal Cyst and Polyp by High-Piched Phonation Characteristics (성대낭종과 성대폴립 간의 고음발성 양상의 차이)

  • Lee, Jong-Ik;Jeong, Go-Eun;Kim, Seong-Tae;Kim, Sang-Yeon;Nam, Soon-Yuhl;Kim, Sang-Yoon;Roh, Jong-Lyel;Choi, Seung-Ho
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.23 no.1
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    • pp.48-51
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    • 2012
  • Background and Objectives : Vocal fold cyst is generally treated by surgical resection, it has a difference with vocal fold polyp, treated by conservative management first. Decrease in mucosal waves is known as main diagnostic criteria of vocal fold cyst. Sometimes there is a difficulty for diffrential diagnosis between cyst and polyp only by endoscopic examination. The purpose of the study is to identify the objective features of vocal cyst and polyp on the basis of voice analysis for the proper differential diagnosis, especially at high pitched phonation. Materials and Method : The voice analysis was done in 15 focal fold cyst patients and 42 vocal fold polyp. Parameters of perceptual assessment, acoustic and aerodynamic measure, and voice range profile were compared between two groups. Results : Vocal fold cyst patients showed significantly reduced MPT by acoustic and aerodynamic analysis, narrowed frequency-range and low maximun frequency by voice range profile analysis compared with vocal fold polyp patient. Maximun frequency 381 Hz is established for cut off value, differential diagnosis between cyst and polyp (ROC analysis, sensitivity 60%, specificity 68%). Conclusion : Voice analysis is helpful for differential diagnosis between vocal fold cyst and polyp, especially there is a difficulty for distinguish cyst from polyp at clinical situation by endoscopic examination. The result of decreased maximum frequncy at vocal fold cyst supports incomplete high-pitched phonation and falsetto regester at vocal fold cyst patients due to decreased mucosal wave, compared with vocal fold polyp patients.

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Transmittance Characteristics of Fishing Lamp in the Anchovy Scoop Fishery (멸치초망어업용 집어등 광력의 수중 투과특성)

  • 박성욱;배봉성;안희춘;서두옥
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.37 no.2
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    • pp.117-123
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    • 2001
  • Anchovy scoop nets, a kind of lift net have been used in the coastal area of Cheju and South sea of Korea. An incandescent lamp(AC 100V, 1kW) is being used as a fishing lamp for gathering anchovy. Fishing lamp was installed at 1m ahead of the prow and 1.5m higher than the water surface. The fishing lamp let fish school rise to the water surface and attract to bag net. Accordingly, a successful anchovy catching depends on controling of fishing lamp. On the study, the distribution of spectral irradiance illumination of incandescent lamp(1kw) and the irradiance efficiency of reflection plate were analyzed and discussed to investigate the ability of fishing lamp which can attract anchovy school effectively. The results obtained are summarized as follows : 1. Around 180% of irradiance efficiency of incandescent lamp was increased by using the reflection plate. The light of lamp was radiated into water with circular shape. 2. The irradiance illumination of incandescent lamp in air was a maximum in wave length of 994nm but it was 690nm at 0.5m and 1.0m of water depth. 3. The relationship between water depth(x) and water illumination(y) of vertical light is represented as follows : y=146.03e supper(-0.37x) 4. The light of incandescent lamp(1kW) pass through much better into vertical direction than horizontal but it was estimated that the light was not able to reach depth of 20m.

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A Study on the High Frequency Ultrasonic Attenuation Characterization in Artificially Aging Degraded 2.25Cr-1Mo Steel (2.25Cr-1Mo 강 인공 열화재의 고주파수 초음파 감쇠특성에 관한 연구)

  • Park, Ik-Keun;Park, Un-Su;Kim, Chung-Seok;Kim, Hyun-Mook;Kwun, Sook-In;Byeon, Jai-Won
    • Journal of the Korean Society for Nondestructive Testing
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    • v.21 no.4
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    • pp.439-445
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    • 2001
  • The destructive method is reliable and widely used lot the estimation of material degradation but, it have time-consuming and a great difficulty in preparing specimens from in-service industrial facilities. Therefore, the estimation of degraded structural materials used at high temperature by nondestructive evaluation such as electric resistance method, replica method, Barkhausen noise method, electro-chemical method and ultrasonic method are strongly desired. Ultrasonic nondestructive evaluation technique has been reported good to attain efficiency of measurement, high sensitivity of measurement, and rapidity and reliability of result interpretation. In this study, it was verified experimentally the feasibility of the evaluation of degraded 2.25Cr-1Mo steel specimens which were prepared by the isothermal aging heat treatment at $630^{\circ}C$ by high frequency longitudinal wave method investigating the change of attenuation coefficient by FFT analysis and wavelet transform. Because of carbide precipitation increase and spheroidization near grain boundary of microstructure to aging degradation, attenuation coefficient had a tendency to increase as degradation proceeded. It was identified possibly to evaluate degradation using the characteristics of high-frequency ultrasonics. Frequency dependence of ultrasonic attenuation coefficient to aging degradation appeared large, which made sure that attenuation coefficient is an important parameter for evaluation of aging degradation.

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Comparison of Runoff Hydrographs based on the Moving Rainstorms (이동강우로 인한 유출수문곡선의 비교)

  • Cho, Yong-Soo;Jeon, Min-Woo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.1737-1741
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    • 2007
  • Using kinematic wave equation, the influence of moving rainstorms to runoff was analysised with a focus on watershed shapes and rainfall distribution types. Watershed shapes used are the oblong, square and elongated shape, and the distribution types of moving storms used are uniform, advanced and intermediate type. The runoff hydrographs according to the rainfall distribution types were simulated and the characteristics were explored for the storms moving down, up and cross the watershed with various velocity. And the hydrographs were compared in the case of varing the rainstorm intensity and varing the rainstorm length in order to make the same total runoff volume. When the rainstorm intensity was varied the shape, peak time and peak runoff of a runoff hydrograph are significantly influenced by spatial and temporal variability in rainfall and watershed shapes. The peak time of down and upstream moving strorms appeared latest in the case of the elongated shape basin, meanwhile at cross stream moving storms, the peak time of elongated shape basin is earlier than the others. For storms moving downstream peak time was more delayed than for other storm direction in the case of elongated watershed. The runoff volume and time base of the hydrograph decreased with the increasing storm speed.

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Development and spectroscopic characteristics of the high-power wave guide He Plasma (도파관식 고출력 헬륨 플라즈마의 개발과 분광학적 특성 연구)

  • Lee, Jong-Man;Cho, Sung-Il;Woo, Jin-Chun;Pak, Yong-Nam
    • Analytical Science and Technology
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    • v.25 no.5
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    • pp.265-272
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    • 2012
  • Okamoto cavity was modified to generate high power (2.45 GHz, 2 kW) He, N2 and Ar plasmas with WR-340 waveguide. Many factors which influence to the plasma generation were optimized and investigated for the spectroscopic properties of the He plasma generated. Some of the important factors are the diameter of the inner conductor, the distance between the inner and outer conductors and the distance between the tip of the inner conductor and the torch. After optimization for the He, two torches (a commercial mini torch for ICP and a tangential flow torch made locally) were compared and showed similar results for the helium plasma gas flow of 25 L/min~30 L/min. A tall torch (extended) was used to block the air in-flow and reduced the background intensity at 340 nm region (NH band). Emission intensity was measured for determination of halogen element in the aqueous solution with power and carrier gas flow rate. Electron number density and the excitation temperature were on the order of $3.67{\times}10^{11}/cm^3$ and 4,350 K, respectively. These values are similar or a bit smaller than other microwave plasmas. It has been possible to analyze aqueous samples. The detection limit for Cl (479.45 nm) was obtained to be 116 mg/L and needs analytical optimization for the better performance.

Hydraulic Characteristics Investigation due to the Change of GapWidth between Artificial Reefs (인공리프 개구폭 변화에 따른 흐름특성 고찰)

  • Kim, Kyu-Han;Shim, Kyu-Tae
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.6
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    • pp.408-415
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    • 2016
  • Small fishing ports and coastal structures installed in a relatively low sea water depth disturb the wave induced current and cause the collapse of equilibrium state of sediment transport. These structures creates diffracted waves and matter the concentration of waves to cause the beach erosion. In order to mitigate these eroding problems on the beach, many counter measurements were proposed such as detached breakwater, groin or headland; however, these methods interrupt the aesthetic view of sandy beach due to the exposed structures above the sea level and have difficulty of applying to those beaches with the good scenery. Furthermore, some of these methods create secondary environmental problems after the installations. To eliminate these problems, one of the countermeasures, artificial reefs have been selected and used worldwide to minimize the disturbance of the scenery and secondary effects on the environment. Meanwhile, it is important to set the design elements for installing the artificial reefs such as that of length, opening width, clearing distances from the shoreline and more. Nevertheless, there are no construction manuals or standards for designing the artificial reefs with these important design elements yet. In this study, different conditions of artificial reefs were used with various cases throughout hydraulic model test to precisely analyze the changes of waves and currents to propose the standards of design elements to install the artificial reefs.

Transmittance Characteristics by candlepower of Incandescent Lamp (백열등의 광력에 따른 수중 투과특성)

  • 박성욱;배봉성;안희춘;이정우;서두옥
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.4
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    • pp.293-299
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    • 2002
  • The anchovy scoop net fishery is one of the important in the South sea and coastal of Jeju of Korea. They are using incandescent lamp as a fishing lamp at night to gather anchovy shoals in the water surface. Fishing lamp (AC 100 V 500 W$\times$2~3 or AC 100 V 1 ㎾$\times$1) was installed at 1 m ahead of the prow and 1.5 m height from the water surface. The fishing lamp let anchovy shoals rise to the water surface and are attracted to bag net. On this study, the distribution of submarine illumination of 1㎾ and 2 ㎾ incandescent lamp were analyzed and discussed to investigate the ability of fishing lamp which can gather anchovy shoals effectively. The submarine illumination of incandescent lamp showed peak in wave length 690 nm. The relationship between submarine illumination (L) and water depth (Z) of 1 ㎾ and 2 ㎾ incandescent lamp in vertical light is 1 ㎾ : L = 3851. 9 $e^{-1.4587Z}$ $R^2$=0.9952 2 ㎾ : L= 8211.9 $e^{-1.2852Z}$ $R^2$=0.9977 The submarine illumination of 2 ㎾ incandescent lamp of 0~4 m layers appeared to be 3 to 4 times higher than 1 ㎾ incandescent lamp, and in more deep layers than 6 m appeared to be equal value of each lamp. The light of incandescent lamp (1 ㎾) pass through much better into vertical direction than horizontal, and submarine illumination of 20 m layers was 1.0 l$\chi$. Therefore, fishing lamp power is thought that 1 ㎾ incandescent lamp is more efficient than 2 ㎾ to gather anchovy shoals in depth of 15~20 m to water surface.

An Experimental Study on the Application of LIBS for the Diagnosis of Concrete Deterioration (콘크리트 열화 진단의 LIBS 적용을 위한 실험적 연구)

  • Woo, Sang-Kyun;Chu, In-Yeop;Youn, Byong-Don
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.6
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    • pp.140-146
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    • 2017
  • It is laser induced breakdown spectroscopy(LIBS) that enables qualitative and quantitative analysis of the elements contained in unknown specimen by comparing the wavelength characteristics of each element obtained from the spectral analysis of the standard specimen with the wavelength analysis results from unknown specimens. In this study, the applicability of LIBS to the analysis of major deterioration factors affecting concrete durability was experimentally analyzed. That is, the possibility of applying LIBS to the diagnosis of concrete deterioration by studying the quantitative detection of harmful deteriorating factors on chloride, sulfate and carbonated mortar specimens using LIBS was studied. As a result of LIBS test for each chloride and sulfate specimen, the LIBS spectral wavelength intensity of chlorine and sulfur ions increased linearly with increasing concentration. Carbon ion LIBS spectral wave intensities of carbonated specimens increased nonlinearly over the duration of carbonation exposure. From the above results, it can be partially confirmed that LIBS can be applied to the diagnosis of concrete deterioration. In case of concrete carbonation, it is presumed that carbon content is contained in the cement itself and is different from the detection of chloride and sulfate specimen. Therefore, it is considered that more various parameter studies should be performed to apply LIBS to concrete carbonation.

Considerations on Wolfgang Weingart's Typography based on Syntactic Characteristics (볼프강 바인가르트의 구문론적 특성에 의한 타이포그래피 고찰)

  • Huh, Jin
    • The Journal of the Korea Contents Association
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    • v.12 no.7
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    • pp.86-93
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    • 2012
  • The foundation of the development in modern typography is based on the era of International Typographical Style and Modern Typography that valued morphological functionality and rationality to achieve an accurate conveyance of meaning. However, with the advance of postmodernism, the view that the aesthetic and conceptual aspect must be included in its interpretation rather than its rational functionality was prominent. Indeed, the works of Dan Friedman and April Greiman, two graphic designers that are known to be the most representative of the post-modernistic era, displayed that graphic design works can also serve as a method for a more free artistic expression, unlike works of Modern Typography. This move towards aesthetic graphics was first started by Wolfgang Weingart. His various attempts at expanding the concept of typography had a significant impact on the development of New Wave and his experimentalist attitude brought about a ground-breaking change to the functional design and formative expression of modern typography. However, this thesis will consider the theoretical background of the typographical designs displayed in Wiengart's works and the experimental methods thereof, and will not attempt to evaluate Weingart's pioneering role and achievements. Furthermore, this thesis will shed new light on the argument that the Weingart's works are not based on the authorship view of post-modernistic typography and are rather utilized to expand the concept of typography based on a syntactical approach.