• Title/Summary/Keyword: Power measurements

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A Study on the Characteristics of Condensable Fine Particles in Flue Gas (배출가스 중 응축성미세먼지 특성 연구)

  • Gong, Buju;Kim, Jonghyeon;Kim, Hyeri;Lee, Sangbo;Kim, Hyungchun;Jo, Jeonghwa;Kim, Jeonghun;Gang, Daeil;Park, Jeong Min;Hong, Jihyung
    • Journal of Korean Society for Atmospheric Environment
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    • v.32 no.5
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    • pp.501-512
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    • 2016
  • The study evaluated methods to measure condensable fine particles in flue gases and measured particulate matter by fuel and material to get precise concentrations and quantities. As a result of the method evaluation, it is required to improve test methods for measuring Condensable Particulate Matter (CPM) emitted after the conventional Filterable Particulate Matter (FPM) measurement process. Relative Standard Deviation (RSD) based on the evaluated analysis process showed that RSD percentages of FPM and CPM were around 27.0~139.5%. As errors in the process of CPM measurement and analysis can be caused while separating and dehydrating organic and inorganic materials from condensed liquid samples, transporting samples, and titrating ammonium hydroxide in the sample, it is required to comply with the exact test procedures. As for characteristics of FPM and CPM concentrations, CPM had about 1.6~63 times higher concentrations than FPM, and CPM caused huge increase in PM mass concentrations. Also, emission concentrations and quantities varied according to the characteristics of each fuel, the size of emitting facilities, operational conditions of emitters, etc. PM in the flue gases mostly consisted of CPM (61~99%), and the result of organic/inorganic component analysis revealed that organic dusts accounted for 30~88%. High-efficiency prevention facilities also had high concentrations of CPM due to large amounts of $NO_x$, and the more fuels, the more inorganic dusts. As a result of comparison between emission coefficients by fuel and the EPA AP-42, FPM had lower result values compared to that in the US materials, and CPM had higher values than FPM. For the emission coefficients of the total PM (FPM+CPM) by industry, that of thermal power stations (bituminous coal) was 71.64 g/ton, and cement manufacturing facility (blended fuels) 18.90 g/ton. In order to estimate emission quantities and coefficients proper to the circumstances of air pollutant-emitting facilities in Korea, measurement data need to be calculated in stages by facility condition according to the CPM measurement method in the study. About 80% of PM in flue gases are CPM, and a half of which are organic dusts that are mostly unknown yet. For effective management and control of PM in flue gases, it is necessary to identify the current conditions through quantitative and qualitative analysis of harmful organic substances, and have more interest in and conduct studies on unknown materials' measurements and behaviors.

Evaluation of $^{14}C$ Behavior Characteristic in Reactor Coolant from Korean PWR NPP's (국내 경수로형 원자로 냉각재 중의 $^{14}C$ 거동 특성 평가)

  • Kang, Duk-Won;Yang, Yang-Hee;Park, Kyong-Rok
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.7 no.1
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    • pp.1-7
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    • 2009
  • This study has been focused on determining the chemical composition of $^{14}C$ - in terms of both organic and inorganic $^{14}C$ contents - in reactor coolant from 3 different PWR's reactor type. The purpose was to evaluate the characteristic of $^{14}C$ that can serve as a basis for reliable estimation of the environmental release at domestic PWR sites. $^{14}C$ is the most important nuclide in the inventory, since it contributes one of the main dose contributors in future release scenarios. The reason for this is its high mobility in the environment, biological availability and long half-life(5730yr). More recent studies - where a more detailed investigation of organic $^{14}C$ species believed to be formed in the coolant under reducing conditions have been made - show that the organic compounds not only are limited to hydrocarbons and CO. Possible organic compounds formed including formaldehyde, formic acid and acetic acid, etc. Under oxidizing conditions shows the oxidized carbon forms, possibly mainly carbon dioxide and bicarbonate forms. Measurements of organic and inorganic $^{14}C$ in various water systems were also performed. The $^{14}C$ inventory in the reactor water was found to be 3.1 GBq/kg in PWR of which less than 10% was in inorganic form. Generally, the $^{14}C$ activity in the water was divided equally between the gas- and water- phase. Even though organic $^{14}C$ compound shows that dominant species during the reactor operation, But during the releasing of $^{14}C$ from the plant stack, chemical forms of $^{14}C$ shows the different composition due to the operation conditions such as temperature, pH, volume control tank venting and shut down chemistry.

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A Microcomputer-Based Data Acquisition System (Microcomputer를 이용(利用)한 Data Acquisition System에 관(關)한 연구(硏究))

  • Kim, Ki Dae;Kim, Soung Rai
    • Journal of Biosystems Engineering
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    • v.7 no.2
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    • pp.18-29
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    • 1983
  • A low cost and versatile data acquisition system for the field and laboratory use was developed by using a single board microcomputer. Data acquisition system based on a Z80 microprocessor was built, tested and modified to obtain the present functional system. The microcomputer developed consists of 6 kB ROM, 5 kB RAM, 6-seven segment LED display, 16-Hex. key and 8 command key board. And it interfaces with an 8 channel, 12 bits A/D converter, a microprinter, EPROM programmer for 2716, and RS232C interface to transfer data between the system and HP3000 mini-computer manufactured by Hewlett Packard Co., A software package was also developed, tested, and modified for the system. This package included drivers for the AID converter, LED display, key board, microprinter, EPROM programmer, and RS232c interface. All of these programs were written in 280 assembler language and converted to machine codes using a cross assembler by HP3000 computer to the system during modifying stage by data transferring unit of this system, then the machine language wrote to the EPROM by this EPROM programmer. The results are summarized as follows: 1. Measuring program developed was able to control the measuring intervals, No. of channels used, and No. of data, where the maximum measuring speed was 58.8 microsec. 2. Calibration of the system was performed with triangle wave generated by a function generator. The results of calibration agreed well to the test results. 3. The measured data was able to be written into EPROM, then the EPROM data was compared with original data. It took only 75 sec. for the developed program to write the data of 2 kB the EPROM. 4. For the slow speed measurements, microprinter instead of EPROM programmer proved to be useful. It took about 15 min. for microprinter to write the data of 2 kB. 5. Modified data transferring unit was very effective in communicating between the system and HP3000 computer. The required time for data transferring was only 1~2 min. 6. By using DC/DC converting devices such as 78-series, 79-series. and TL497 IC, this system was modified to convert the only one input power sources to the various powers. The available power sources of the system was DC 7~25 V and 1.8 A.

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Comparison of Horizontal and Vertical Noise Power Spectrum in Measurements by Using Various Electronic Portal Imaging Devices in Radiation Therapy (방사선치료 시 전자포털 영상장치를 이용한 잡음전력스펙트럼 수평 및 수직 측정비교)

  • Kim, Ki-Won;Choi, Kwan-Woo;Jeong, Hoi-Woun;Jang, Seo-Goo;Kwon, Kyung-Tae;Son, Soon-Yong;Son, Jin-Hyun;Min, Jung-Whan
    • Journal of radiological science and technology
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    • v.39 no.2
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    • pp.171-176
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    • 2016
  • The quality assurance (QA) is very important for diagnostic field and radiation therapy field to evaluate the characteristic of devices. The purpose of this study was to compare different NPS methodologies results which are measuring NPS with regard to horizontal and vertical directions by using megavoltage X-ray energies. The NPS evaluation methods were applied to the International Electro-technical Commission standard (IEC 62220-1). The electronic portal imaging devices (EPID) devices such as Siemens BEAMVIEW$^{PLUS}$, Elekta iViewGT and Varian Clinac$^R$ iX aS1000 were used. NPS data were expressed by corresponding each frequency about average of noise value corresponding the each frequency, and NPS were evaluated quantitatively by totaling up the noise values of average frequency which are on horizontal and vertical directions. In NPS results for Elekta iViewGT, NPS of horizontal and vertical by using 4 methods were indicated the difference of 3~5% between horizontal and vertical direction. In the results of Siemens BEAMVIEW$^{PLUS}$ and Varian Clinac$^R$ iX aS1000, the NPS of horizontal and vertical direction were indicated the difference of 15% when averaging the whole values. This study were evaluated the NPS of each devices by totaling up the noise values of average frequency which are on horizontal and vertical directions suggesting the quantitative evaluation method using the data.

Four-Channel Differential CMOS Optical Transimpedance Amplifier Arrays for Panoramic Scan LADAR Systems (파노라믹 스캔 라이다 시스템용 4-채널 차동 CMOS 광트랜스 임피던스 증폭기 어레이)

  • Kim, Sang Gyun;Jung, Seung Hwan;Kim, Seung Hoon;Ying, Xiao;Choi, Hanbyul;Hong, Chaerin;Lee, Kyungmin;Eo, Yun Seong;Park, Sung Min
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.9
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    • pp.82-90
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    • 2014
  • In this paper, a couple of 4-channel differential transimpedance amplifier arrays are realized in a standard 0.18um CMOS technology for the applications of linear LADAR(laser detection and ranging) systems. Each array targets 1.25-Gb/s operations, where the current-mode chip consists of current-mirror input stage, a single-to-differential amplifier, and an output buffer. The input stage exploits the local feedback current-mirror configuration for low input resistance and low noise characteristics. Measurements demonstrate that each channel achieves $69-dB{\Omega}$ transimpedance gain, 2.2-GHz bandwidth, 21.5-pA/sqrt(Hz) average noise current spectral density (corresponding to the optical sensitivity of -20.5-dBm), and the 4-channel total power dissipation of 147.6-mW from a single 1.8-V supply. The measured eye-diagrams confirms wide and clear eye-openings for 1.25-Gb/s operations. Meanwhile, the voltage-mode chip consists of inverter input stage for low noise characteristics, a single-to-differential amplifier, and an output buffer. Test chips reveal that each channel achieves $73-dB{\Omega}$ transimpedance gain, 1.1-GHz bandwidth, 13.2-pA/sqrt(Hz) average noise current spectral density (corresponding to the optical sensitivity of -22.8-dBm), and the 4-channel total power dissipation of 138.4-mW from a single 1.8-V supply. The measured eye-diagrams confirms wide and clear eye-openings for 1.25-Gb/s operations.

An Empirical Study on How the Moderating Effects of Individual Cultural Characteristics towards a Specific Target Affects User Experience: Based on the Survey Results of Four Types of Digital Device Users in the US, Germany, and Russia (특정 대상에 대한 개인 수준의 문화적 성향이 사용자 경험에 미치는 조절효과에 대한 실증적 연구: 미국, 독일, 러시아의 4개 디지털 기기 사용자를 대상으로)

  • Lee, In-Seong;Choi, Gi-Woong;Kim, So-Lyung;Lee, Ki-Ho;Kim, Jin-Woo
    • Asia pacific journal of information systems
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    • v.19 no.1
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    • pp.113-145
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    • 2009
  • Recently, due to the globalization of the IT(Information Technology) market, devices and systems designed in one country are used in other countries as well. This phenomenon is becoming the key factor for increased interest on cross-cultural, or cross-national, research within the IT area. However, as the IT market is becoming bigger and more globalized, a great number of IT practitioners are having difficulty in designing and developing devices or systems which can provide optimal experience. This is because not only tangible factors such as language and a country's economic or industrial power affect the user experience of a certain device or system but also invisible and intangible factors as well. Among such invisible and intangible factors, the cultural characteristics of users from different countries may affect the user experience of certain devices or systems because cultural characteristics affect how they understand and interpret the devices or systems. In other words, when users evaluate the quality of overall user experience, the cultural characteristics of each user act as a perceptual lens that leads the user to focus on a certain elements of experience. Therefore, there is a need within the IT field to consider cultural characteristics when designing or developing certain devices or systems and plan a strategy for localization. In such an environment, existing IS studies identify the culture with the country, emphasize the importance of culture in a national level perspective, and hypothesize that users within the same country have same cultural characteristics. Under such assumptions, these studies focus on the moderating effects of cultural characteristics on a national level within a certain theoretical framework. This has already been suggested by cross-cultural studies conducted by scholars such as Hofstede(1980) in providing numerical research results and measurement items for cultural characteristics and using such results or items as they increase the efficiency of studies. However, such national level culture has its limitations in forecasting and explaining individual-level behaviors such as voluntary device or system usage. This is because individual cultural characteristics are the outcome of not only the national culture but also the culture of a race, company, local area, family, and other groups that are formulated through interaction within the group. Therefore, national or nationally dominant cultural characteristics may have its limitations in forecasting and explaining the cultural characteristics of an individual. Moreover, past studies in psychology suggest a possibility that there exist different cultural characteristics within a single individual depending on the subject being measured or its context. For example, in relation to individual vs. collective characteristics, which is one of the major cultural characteristics, an individual may show collectivistic characteristics when he or she is with family or friends but show individualistic characteristics in his or her workplace. Therefore, this study acknowledged such limitations of past studies and conducted a research within the framework of 'theoretically integrated model of user satisfaction and emotional attachment', which was developed through a former study, on how the effects of different experience elements on emotional attachment or user satisfaction are differentiated depending on the individual cultural characteristics related to a system or device usage. In order to do this, this study hypothesized the moderating effects of four cultural dimensions (uncertainty avoidance, individualism vs, collectivism, masculinity vs. femininity, and power distance) as suggested by Hofstede(1980) within the theoretically integrated model of emotional attachment and user satisfaction. Statistical tests were then implemented on these moderating effects through conducting surveys with users of four digital devices (mobile phone, MP3 player, LCD TV, and refrigerator) in three countries (US, Germany, and Russia). In order to explain and forecast the behavior of personal device or system users, individual cultural characteristics must be measured, and depending on the target device or system, measurements must be measured independently. Through this suggestion, this study hopes to provide new and useful perspectives for future IS research.

Effects of Yohimbine and Atipamezole in Dogs Anesthetized with Xylazine-Ketamine Combination on EEG (Yohimbine과 Atipamezole이 Xylazine-Ketamine 병용 마취견의 뇌파에 미치는 영향)

  • 장환수;장광호;이만기;장인호
    • Journal of Veterinary Clinics
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    • v.19 no.2
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    • pp.174-185
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    • 2002
  • We investigated the effects of yohimbine and atipamezole in dogs anesthetized with xylazine-ketamine combination on electroencephalography (EEG) . Experiment groups were divided into three according to antagonists . Saline (1 ml) was used as an antagonist in group C, yohimbine (0.1 mg/kg) in group Y and atipamezole (50 ug/kg) in group A. Each group consisted of 5 dogs. Glycopyrrolate was injected 15 minutes prior to xylazine injection. Xylazine (1.1 mg/kg, IM) and ketamime (10 mg/kg, IV) were injected with the interval of 10 minutes. After 15 minutes, antagonists were administered intravenously. For EEG measurements, a recording electrode was positioned at Cz, which was applied to International 10-20 system. Heart rates, body temperature, respiratory rates, arterial blood pressure, $PaO_2$$PaCO_2$$PaCO_2$ at S4 in group Y was significantly decreased(p<0.05). Changes of electrolytes were not significant, except value of $Cl^-$ at S3 in group A. Mean head-up time (the time dogs showing head-up movement after antagonist injection, minutes) was $38.23^{\circ}$ae6.46 in group C, 2.54 $\pm$ 0.93 in group Y and 2.12$\pm$ 1.32 in group A. Mean sternal recumbent time (the time dogs showing sternal recumbency after antagonist injection, minutes) was 45.93$\pm$ 10.27 in group C, 11.91 $\pm$ 7.19 in group Y and 9.88$\pm$ 3.38 in group A. Mean walking time (minutes) was 53.49$\pm$ 9.21 in group C, 22.10$\pm$ 11.10 in group Y and 18.48$\pm$ 4.39 in group A. In group Y all dogs showed excitation and muscle rigidity in emergence. In group A, two dogs were also showed excitation and muscle rigidity, but were weaker than those of group Y.

Change of Spherical Aberration with Aspheric Soft Contact Lens Wear (비구면 소프트콘택트렌즈 착용에 의한 눈의 구면수차 변화)

  • Kim, Jeong Mee;Mun, Mi-Young;Kim, Young Chul;Lee, Koon-Ja
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.4
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    • pp.365-372
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    • 2012
  • Purpose: To investigate ocular higher order aberrations (HOA) and spherical aberration changes caused by an aspheric soft contact lens designed to reduce spherical aberration (SA) of the eye. Methods: Fifty subjects who have successfully experienced soft contact lenses were refitted with aspheric design (Soflens Daily Disposable: SDD, Bausch+Lomb) soft contact lens. Ocular higher order aberrations (HOA) and stand alone SA were measured and analyzed for a 4-mm pupil size using Wave-Scan Wavefront$^{TM}$ aberrometer (VISX, Santa Clara, CA, USA). High and low contrast log MAR visual acuity and contrast sensitivity function (CSF) were also measured under photopic and mesopic conditions (OPTEC 6500 Vision Tester$^{(R)}$). All measurements were conducted monocularly with an undilated pupil. Results: The RMS mean values for total HOA with SDD contact lenses were significantly lower than those at with unaided eyes (p<0.001) and a reduction for SA in the SDD was close to the baseline SA (zero ${\mu}m$) (p<0.001). For the SDD lens, there was a statistically significant correlation between the changes in the total HOA and the contact lens power (r=0.237, p=0.018) as well as between the changes in SA and the lens power (r=0.324, p=0.001). High contrast visual acuity (HCVA) and low contrast visual acuity (LCVA) with SDD lenses were $-0.063{\pm}0.062$ and $0.119{\pm}0.060$, respectively under photopic and $-0.003{\pm}0.063$ and $0.198{\pm}0.067$, respectively under mesopic condition. Contrast Sensitivity Function (CSF) with SDD lenses under both photopic and mesopic conditions was $3.095{\pm}0.068$ and $3.087{\pm}0.074$, respectively. Conclusions: The SDD contact lens designed to control SA reduced the total ocular HOA and SA of the eye, resulting in compensating for positive SA of the eyes. Thus, the optical benefits of the lens with SA control would be adopted for improving the quality of vision.

The Variation of Leaf Characterics in 6 Natural Populations of Stewartia koreana Nakai (노각나무 6개 천연집단(天然集團)의 엽형질(葉形質) 변이(變異))

  • Kim, Young-Jung;Kim, Kee-Chul;Lee, Byung Sil;Lee, Gab-Yeoun;Cho, Kyoung-Jin;Kang, Jin Taek;Kim, Tae-Dong
    • Journal of Korean Society of Forest Science
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    • v.94 no.6
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    • pp.446-452
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    • 2005
  • In order to examine the natural distribution variations between groups of the Stewartia koreana, the leaf form characteristics of the investigation sites were analyzed by each group. As a result, the Mt. Kumsan group showed a smaller value in leaf length, width, area, and the number of veins, but not in the petiole length and serration number. Among each character, the coefficient of variation(CV) of the characters excluding petiole length and leaf area was in a comparatively narrow range, from 11.6~17.4%. On the other hand, the CV of petiole length and leaf area between the groups was 34.9% and 28.4% respectively. The CV of these characters within the group was also extraordinary- petiole length showed 29.5~42% and leaf area showed 27.7~40.7%. Also, the simple correlation analysis between 12 leaf characteristics showed that the correlation between leaf width and leaf area was high (r=0.975). The correlations between leaf length and leaf area, between leaf length and leaf width were 0.971 and 0.969, respectively. A negative correlation between angle of leaf base and ratio of leaf length to leaf width was discovered (r= -0.843), meaning that the ratio of leaf length to leaf width decreases as angle of leaf base increases. A cluster analysis was enforced among leaf characteristics of the selected group as a standard on the similarity of quantitative, qualitative measurements. The results showed that at a 0.4 distance level, the subjects could be classified into 4 groups. Group 1 was the Mt. Jogyesan and Mt. Kayasan group, group 2 was Mt. Paegunsan, group 3 was Mt. Unmunsan and Mt. Mudungsan, and group 4 was Mt. Kumsan. At a distance level of 0.6, the subjects were classified into two groups. Group 1 was the Mt. Ktimsan group and group 2 was Mt. Mudungsan, Unmunsan, Paegunsan, Kayasan, and Cogyesan. Especially the Mt. Kumsan group had the smallest value in the leaf characteristics of leaf length, width, area, and the number of veins, showing an obvious difference from the other five groups. There were five principal components that had a meaningful eigenvalue over 1.0 among the 12 extracted components. The explanatory power of the top two main components (leaf length and width) on the total variation was 52.7%. The explanatory power was 91.3% when all 5 main components were included.

A Study on Real-Time Defect Detection Using Ultrasound Excited Thermography (초음파 서모그라피를 이용한 실시간 결함 검출에 대한 연구)

  • Cho, Jai-Wan;Seo, Yong-Chil;Jung, Seung-Ho;Jung, Hyun-Kyu;Kim, Seung-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.4
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    • pp.211-219
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    • 2006
  • The UET(ultrasound excited thermography) for the ,eat-time diagnostics of the object employs an infrared camera to image defects of the surface and subsurface which are locally heated using high-frequency putted ultrasonic excitation. The dissipation of high-power ultrasonic energy around the feces of the defects causes an increase In temperature. The defect's image appears as a hot spot (bright IR source) within a dark background field. The UET for nondestructive diagnostic and evaluation is based on the image analysis of the hot spot as a local response to ultrasonic excited heat deposition. In this paper the applicability of VET for fast imaging of defect is described. The ultrasonic energy is injected into the sample through a transducer in the vertical and horizontal directions respectively. The voltage applied to the transducer is measured by digital oscilloscope, and the waveform are compared. Measurements were performed on four kinds of materials: SUS fatigue crack specimen(thickness 14mm), PCB plate(1.8 mm), CFRP plate(3 mm) and Inconel 600 plate (1 mm). A high power ultrasonic energy with pulse durations of 250ms Is injected into the samples in the horizontal and vertical directions respectively The obtained experimental result reveals that the dissipation loss of the ultrasonic energy In the vertical injection is less than that in the horizontal direction. In the cafe or PCB, CFRP, the size of hot spot in the vortical injection if larger than that in horizontal direction. Duration time of the hot spot in the vertical direction is three times as long as that in the horizontal direction. In the case of Inconel 600 plate and SUS sample, the hot spot in the horizontal injection was detected faster than that in the vertical direction