• Title/Summary/Keyword: Portable equipment

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Impedance Measurement and Matching Technique for Medium-Voltage Powerline Communication (고압전력선 통신을 위한 임피던스 측정 및 정합 방안 연구)

  • 이재조;유정훈;홍충선;이대영
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.5
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    • pp.345-352
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    • 2004
  • Currently, high data rate PLC(Power Line Communications), up to 100 Mbps, which use frequency bandwidth between 2 MHz and 30 MHz is investigated very hard, and commercial PLC modem for low voltage powerline network (indoor) is coming soon into communication market. For the purpose of developing a fit communication system which has little distortion of signal and attenuation, it is surely necessary to know about channel environments of powerline. Especially, the impedance measurement of the powerline and impedance matching are very important. As is known, since medium-voltage powerline (22.9 ㎸) is still working, it is not so simple to measure the powerline impedance. In our study, a portable impedance measurement equipment is developed. It consists of coupling capacitor, a drain coil and impedance matching transformer. The equipment is easily connected to medium voltage line and impedance of power line is measured using a network analyzer. Also, measurement results are used for impedance matching of PLC signal. In fact, matching transformer with several different impedances are used. The matching transformer is connected between coupling capacitor and signal port. In this paper, the developed portable impedance measurement equipment and impedance measurement results are presented. Also impedance matching technique using matching transformers will be explained. We showed the result of the improved performance by the impedance matching.

Effects on Sight, Quickness, Balance, Pain of Normal Human Body with Using Portable Mobile Phone (스마트폰 사용이 정상인의 시력, 순발력, 균형능력, 통증에 미치는 영향)

  • Kang, Su-Jeong;Kim, Kyeong-Ha;Kim, Chi-Hyok
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.18 no.2
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    • pp.95-102
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    • 2012
  • Background: The purpose of this study was to find out influence of using portable mobile devices in human body. Method: The subjects were consisted of the normal persons (19 males and 20 females). These subjects were consisted of three groups according to test time. The A group (12 persons - 6 males, 6 females) tests 5 minutes, the B group (14 persons - 7 males, 7 females) tests 10 minutes, and the C group (13 persons - 6 males, 7 females) tests 15 minutes. Before test, sight, quickness and balance were measured, after test revision, quickness, balance were measured and checked pain scale. Results: The results were as follows. 1. Sight, quickness and balance were decreased and pains were increased after using portable mobile devices than before using these. 2. According to duration of using the portable mobile devices, sight, quickness and balance was not a statistically significant difference, the entire upper body pain was a statistically significant difference. When viewed as part of the pain, shoulder, lower back, and wrist pain were a statistically significant difference, but the neck and elbow were not a statistically significant difference. 3. The influence of vision according to distance of using Portable mobile devices was no statistically significant difference. In addition, less than 20cm distance using equipment group ("Ga") and the group ("Na") which exceeded 20cm in between the sight were not statistically significant difference, Influence of pain according to distance of using Portable mobile devices we-re no statistically significant differences. Conclusion: Using portable mobile devices affect human body on the elements of the biomechanics.

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The Ground Investigation Technique of Railway Using Pagani Cone Test (Pagani Cone Test를 이용한 철도노반 조사 기법 연구)

  • Cho, Eun-Kyung;Cho, Kook-Hwan
    • Journal of the Korean Society for Railway
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    • v.19 no.6
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    • pp.792-801
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    • 2016
  • Standard Penetration Test (SPT) and Cone Penetration Test (CPT) are widely used in geotechnical investigation methods for railway roadbed. However, SPT can not be used on the Railway track, since the equipment may contact to the electric lines. However, a portable equipment can be used for geotechnical investigation without electrical hazard. Dynamic Cone Penetrometer (DCP) is one of representative portable equipments. A normal portable DCP has usually not enough driving energy and the rigidity of cone-rod, so it is impossible to investigate the required investigate penetration depth. In this study, The adaptability of Pagani cone test which is one of portable dynamic cone penetrometer is studied and compared with SPT-N data. As a result of this study, the proposed correlation factors between Pagani cone test and SPT-N values after corrections is 1.48 for sandy soil and 1.33 for clayey soil.

Power Support Device (PSD) Based Authentication Protocol for Secure WiBro Services (안전한 WiBro 서비스를 위한 PSD(Power Support Device) 기반 인증 프로토콜)

  • Lee, Gi-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.3
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    • pp.727-733
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    • 2008
  • An authentication between a user's terminal and a Access Control Router (ACR) is preceded so that a user receives secure WiBro services. Otherwise they can be exposed from many attack risks. So the Telecommunications Technology Association (TTA) constituted a mechanism of the mutual authentication for WiBro service. In mechanism a user executes the mutual authentication between a Portable Equipment (PE) and the ACR by using Portable Internet Subscriber Identity Module (PISIM). But this standard needs many message to authenticate the ACR and the users cann't use wireless Internet service. Therefore in this paper we propose the key agreement protocol between the PSS and the ACR to authenticate the PSS to ACR. At this time Power Support Device (PSD) fer supporting the calculated quantity of the PSS is participated in the key agreement protocol. The ACR sends a generated key to Key Authentication Server (KAS) via secure IPsec tunnel and then it preserves the identity of the PSS and the value of key after it enciphered them. In conclusion we analyze the security and efficiency of the proposed protocol.

Comparison of the bovine blood gas parameters produced with three types of portable blood gas analyzers

  • Ro, Younghye;Choi, Woojae;Hong, Leegon;Kim, Eunkyung;Choe, Eunhui;Kim, Danil
    • Journal of Veterinary Science
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    • v.23 no.4
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    • pp.60.1-60.6
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    • 2022
  • Background: A definite diagnosis should be made in the bovine practice field, however, it was difficult to perform laboratory analysis immediately. Currently, three types of portable blood gas analyzers are available in Korea. Objectives: This study aimed to evaluate the correlations among these three analyzers. Methods: Seventy-two plasma samples from Holstein-Friesian cows were used for blood gas analysis, and three instruments (EDAN i15 Vet, VETSCAN i-STAT, and EPOC) were operated simultaneously. Moreover, plasma calcium levels were compared between these portable analyzers and blood chemistry device, which is usually used in a laboratory environment. Pearson analysis was performed to confirm the correlation of each parameter produced with the three instruments and blood chemistry analyzer. Results: As results, high correlation was observed in parameters of pH, pO2, potassium ion, ionized calcium, and glucose (p < 0.001, r > 0.7). In addition, pCO2 showed a moderate correlation among the three analyzers (p < 0.001, r > 0.5), and there was no correlation among all instruments for sodium ions. There was also a high correlation between ionized calcium from the three portable devices and total calcium from the biochemistry analyzer (p < 0.001, r > 0.9). Conclusions: In conclusion, there was a high correlation between results from the three different blood gas analyzers used in the bovine clinical field in Korea. Thus, a consistent diagnosis can be made even with different equipment if the operator is aware of the strengths and weaknesses of each piece of equipment and operates it properly.

A Pilot Study on Emission Analysis of Air Pollutants Produced from Portable Recycling of Asphalt Concrete (간이이동법에 의한 폐아스콘 재생시 대기오염물의 배출분석에 대한 실험적 연구)

  • Lee, Byeong-Kyu;Kim, Haeng-Ah;Jeong, Ui-Ryang;Duong, Trang;Chae, Po-Gi;Park, Kyung-Won
    • Journal of Environmental Science International
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    • v.16 no.3
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    • pp.385-392
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    • 2007
  • Currently, portable equipment for recycling of waste asphalt concrete (ASCON) has been used. However, any air pollution control devices are not attached in the simple portable one. Thus, a lot of air pollutants have been produced from recycling processes of waste ASCON which resulted from aging of paved roads or repavement of roads. This study deals with a preliminary result of concentration analysis of air pollutants obtained from a pilot and a real recycling processes of waste ASCON using simple portable recycling equipment. Air pollutants were taken from 4 steps of the pilot recycling process including an initial heating by liquid petroleum gas (LPG), intermediate heating and melting (H&M) process, final H&M process, and pavement processes using recycled ASCON at the recycling site. Also, air pollutants were taken front 4 steps of the real recycling processes including an initial H&M, final H&M and mixing, loading of recycled ASCON to dump trucks, and at the recycling site after leaving the loaded dump trucks for real pavement sites. The air pollutants measured in this study include volatile organic compounds (VOCs), aldehydes, particulate matter (PM: PM1, PM2.5, PM7, PM10, TSP (total suspended particulate)). The identified concentrations of VOCs increased with increasing time or degree for H&M of waste ASCON. In particular, very high concentrations of the VOCs at the status of complete melting, which is exposed to the air, of the waste ASCON just before paving tv the recycled ASCON at the recycling site. Also, considerable amount of VOCs were identified from the recycling equipment after the dump trucks leaded by recycled ASCON leaved the recycling site for the pavement sites. The relative level of formaldehyde exceeded 80% of the aldehydes Identified in the recycling processes. This is because the waste ASCON is exposed to direct flame of LPG during H&M processes. The PM concentrations measured in the winter recycling processes, such as the loading and rotation processes of waste ASCON into/in the recycling equipment for H&M, were much higher than those in the summer ones. In particular, the concentrations of coarse particles such as PM7 and PM10 during the winter recycling were very high as compared those during the summer one.

Design and Implementation of a Walking Beat Game Machine Using Frequency Analysis (주파수 분석을 이용한 워킹 비트 게임기 설계 및 구현)

  • 이건학;김도현;안현식
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.123-126
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    • 2000
  • In this paper, the portable game machine called W"alking Beat" is designed and implemented not only to propose the new possibilities for the peripheral equipment market of portable acoustic machine but also to overcome the limitation of the acoustic simulation game machine such as the existing Beat Mania. The old game machine can be used only in a particular place, where it is installed. However, in order to get over the constraint on this space problem "Walking Beat Game Machine" is designed to facilitate the portability. In addition, the frequency analysis method using FFT algorithm is employed by regarding the music data for the portable digital acoustic machine as source so that the limitation that the existing game machine depends heavily on the previously registered game contents can be overcome. By making it possible to play games for all the music and putting an emphasis on multimedia trend only to listen to the music, it is speculated that it can contribute to the development of the new culture in the near future.

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A Study on Effective Information Transfer Technique between Personal Computer and Portable Equipment (개인용 컴퓨터와 휴대장치간의 효과적 정보 전송기법 연구)

  • Choi, Gyoo-Seok;Park, Jong-Jin;Kang, Jung-Jin;Kim, Woong Jae
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.2
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    • pp.261-267
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    • 2013
  • In this paper, the effective information transfer technique between computing device and portable device that is connected through USB interface has been studied. The proposed technique is realized by the method which portable device is perceived into optical media such as CD-ROM or CD-R/W through SCSI commands on USB interface. Through the proposed system in this study, we maximized user convenience by executing diverse works using stored data in a portable device without installing extra USB driver corresponding to portable device, when user data is transmitted between computing device and portable device. We conducted experimental tests to verify the performance of the proposed system through implementing of test system. As a result, we confirmed the technique is comparatively superior to existing method in transmitting speed and user convenience.

Development of an Equipment for Monitoring Current and Voltage on a Power Transmission Line

  • K. Kuwanami;E.Jishiuama;T Matsuda;I.Oota;H.Kuribayashi;N. Ueda;Ha, S.yata
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.233-236
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    • 2000
  • A portable equipment that measures a current and voltage waveform of power transmission lines is pro-posed. In the equipment, the current and voltage, respectively, are detected by a loop coil and a capacitor clamped around the power lines. The detected data is transmitted by an FM wave to the receiver on the ground station. Since the receiver is isolated from the power lines, we do not require high potential insulators for the measurement of current and voltage. The proposed equipment is therefore, small-sized, light, and low in the cost of production. Experimental results presented here show that the equipment can monitor the current flowing in single wire over a ground plane and the potential of the wire.

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A Study on the 900MHz FDD Tranceiver for the Vessel (900MHz대 FDD방식을 이용한 선내용 Tranceiver에 관한 연구)

  • 송면규;조학현;김정년
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.3
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    • pp.359-365
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    • 1998
  • The portable two way radio telephone amongst GMDSS equipment in the vessel is very important portable wireless one for search and rescue in distress situation. Although the portable two way radio telephone must be equipped with in the vessel by IMO & RR, other kinds of wireless tranceivers are widely used to communicate with crew members who are separately appointed at bridge forecastle and poop in leaving or arriving at the port, passing through a narrow canal or voyaging in the foggy weather, Most of those wireless tranceivers except portable two way radio telephone are allocated at 27MHz band with PTT simplex system that makes crew members difficult to work effectively in the vessel. In this research 900MHz band FDD(frequency duplex division) tranceiver system is studied to help crew members in the vessel to communicate with themselves freely and to work easily meanwhile with simple operation. 900MHz band FDD tranceiver system uses one chip FM frontend IC to realize the miniaturization and downsizing of tranceiver and small size head set attached to helmet. The credibility of this research's result is highly evaluated by circuit analysis with computer aided simulation, and partly modified 900MHz band cordless phone circuit.

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