• Hwankyungkyoyuk
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• v.24 no.1
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• pp.49-65
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• 2011

This paper explored undergraduates' LoHAS purchasing behavior and factors influencing the behavior, including' self-construal, and LoHAS values, attitudes and behavior. First, this study investigated how self-construal affected LoHAS values, and then analyzed how LoHAS values influenced LoHAS attitude and behavior. We administerd a survey with undergraduates attending a university located in the metropolitan area. The analysis results indicate that ecological self-construal affects LoHAS values. According to the analysis, both environmentalism and sustain ability of LoHAS values also affect LoHAS attitude, and then the attitude influences LoHAS behavior. This study shows the casual relationship between variables including self-construal, LoHAS values, attitude and behavior. In particular, this finding confirms that self-construal as one of psychological factors affects LoHAS consumers' values and behavior.

• Journal of KIISE
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• v.45 no.3
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• pp.303-310
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• 2018

LoRaWAN(Long Range Wide Area Network) is a standard for low-power, long-range, low-speed communication as announced in the LoRa Alliance. LoRaWAN addresses the physical layer and medium access control layer and the technology used in the physical layer is referred to as LoRa. LoRa can be used for remote monitoring and remote control in maritime conditions. However, unlike land, marine environment is not only difficult to construct an infrastructure for service provision, but also difficult to analyze LoRa performance in maritime. In this study, we construct an infrastructure using cloud platform and analyze LoRa link performance in maritime conditions.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.549-555
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• 2023

The representative technology of the WWAN wireless communication network used in the Internet of Things is LoRa communication technology, and LoRa communication uses the ISM band. The 920 MHz (920.9 MHz~923.3 MHz) band frequency, which is used as a domestic LoRa frequency, had a problem in performing LoRa network practice in the curriculum using a commercially available LoRa modules that have been used in Europe and the United States because of different frequency band, but a RYLR896 LoRa module was developed that allowed RF frequency to be programmed. With this module, this paper confirmed that the frequency can be set at a specified frequency in Korea using AT commands. In addition, using these RYLR896 LoRa modules, a LoRa network consisting of end nodes and gateways was constructed and practiced to confirm that development equipment capable of practicing the RYLR896 LoRa module and IoT was operating normally.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1392-1398
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• 2000

In this paper, Sub Harmonic Ring Mixer using Anti-Parallel Diode Pair is studied. Conventional mixers mix LO signal with RF signal and, obtain IF signal from the difference between LO and RF. Sub harmonic ring mixers using APDP mix RF signal with the second harmonic of LO signal, LO frequency needed for conventional receiver is reduced by 1/2.The produced mixer showed 12 dB conversion loss, and 1 dB compression point of IF signal, in respect to RF signal, was found at the 0 dBm RF signal. Isolation LO/IF and LO/RF is 24.6 dB and 22.5 dB respectively. Isolation RF/LO and LO/RF is 32.6 dB and 22.5 dB respectively.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.875-879
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• 2004

In this paper, sub-harmonic pumped(SHP) mixer using anti-parallel diode pair(APDP) is designed for 5 GHz band wireless communication system. Conventional mixers mix LO with RF, and obtain IF signal from the difference between LO and RF. As the frequency increase, LO signal requires higher LO power, better phase noise characteristics, more stable La. However, using APDP, the SHP mixer mixes the 2nd harmonics of LO signal. Therefore, the SHP mixer has an advantage that the LO signal frequency required for IF signal is reduced at half value of LO fundamental frequency. When LO power is 3 dBm, the conversion loss of manufactured SHP mixer is 12.83 dB. The isolation of LO/IF, 2LO/IF, RF/1F and LO/RF is 39.17 dB, 58 dB, 34 dB, and 67.9 dB. respectively. For this case, IP3 at input is 8 dBm.

• Journal of IKEEE
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• v.8 no.1 s.14
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• pp.79-85
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• 2004

In this paper, Sub harmonic mixer using anti-parallel diode pair is designed for 5.8 GHz Wireless LAN. Conventional mixers mix LO with RF and obtain IF signal from the difference between LO and RF. As frequency increase, LO signal is required increasing LO power, better phase noise, stable LO. But, using APDP, the SHP mixer mix the harmonics of LO signal. Therefore, Sub harmonic mixer is advantage that necessary LO signal frequency was used to operate the 1/2. When LO power is 3 dBm, the conversion loss of manufactured SHP mixer is 12.83 dB. The isolation of LO/IF, 2LO/IF, RF/IF and LO/RF is 39.17 dB, 58 dB, 34 dB, 67.9 dB. And IIP3 is 8 dBm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.139-141
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• 2019

This paper proposes the application of LoRa network, which has been under various research recently, to use control system for the transfer of Unmanned Vehicle. LoRa( Long Range) has a wide coverage of up to30 km, and is characterized by large-scale low-power long-distance radio communication. LoRa has already been studied in various industries. It is also proposed to study various functions by utilizing LoRa network and applying it to the control system of the uninhabited entity.

• Journal of electromagnetic engineering and science
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• v.2 no.1
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• pp.56-58
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• 2002

In this paper, the double conversion gate mixer using a half-LO frequency is described at 25 GHz band. The proposed mixer uses two HEMTs excited by a single LO signal of half-LO frequency in order to generate the second IF signal. That is, the LO signal having the half-LO frequency is only fed into the gate of the first HEMT mixer as a normal gate mixer. The LO signal through the first mixer is find into the second mixer The proposed miler requires not only half of the normal LO frequency, but also lower LO power than the conventional subharmonically pumped milers. Over the bandwidth of 500 MHz at 24.5 GHz, the conversion gain is 2.5 dB, the noise figure is 9 dB, and the isolation between RF and LO port is 32 dB when the LO poller is 0 dBm at 12.65 GHz.

• Journal of IKEEE
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• v.3 no.1 s.4
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• pp.69-78
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• 1999

In this paper, direct conversion receiver was designed to even harmonic anti-paralled diode pair ring mixer. Using a second harmonic component of LO instead of LO signal and RF signal are mixed by SHP(Sub Harmonic Pumped) mixer with anti-parallel diode pair. Canceling the harmonics of LO signal in ring mixer, SHP mixer using anti-parallel diode pair could mostly reduce the radiation of LO signal through a input port the most, good isolation characteristic, and low spurious characteristic by LO signal was shown over broad band. The produced SHP mixer showed LO/IF, RF/IF and LO/RF isolation was 24.6dB,36.2dB and 22.5dB respectively. And conversion loss was measured 15.6dB, IF output -35.6dBm with -20dBm RF input and 5.5dBm LO signal. 1dB compression point of If signal, in respect to RF signal, was found at the 0dbm RF signal.

• Journal of Information Technology Services
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• v.13 no.4
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• pp.205-230
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• 2014

In recent years, the social network service (SNS) and the location-based social network service (LBSNS) industry is expanding and the competition within the field is increasing much more. Since 2010, the full-scaled studies of SNS and LBSNS have begun. With the growth of SNS and LBSNS markets, SoLoMo (Social-Local-Mobile) is also becoming the trend for applications in different fields. However, despite the importance of SoLoMo, there have been little studies on the characteristics of SoLoMo applications. The purpose of this research is to investigate the effect of characteristics and perceived privacy risk of mobile location-based SNS on intention to use SoLoMo applications. For the purpose, we proposed a SoLoMo service acceptance model with TAM (Technology Acceptance Model) and the characteristics of SoLoMo applications. The characteristics consist of three factors, i.e. SNS, location, and mobile-related factors. This study also considered a gamification and a perceived privacy risk factor influencing on SoLoMo service usage in our proposed research model. The results of our empirical analysis using partial least squares (PLS) method show that the characteristics of SoLoMo applications including SNS, location, and mobile-related features, gamification, and perceived privacy risk have partially an effect on intention to use SoLoMo applications. Based on these results, SoLoMo-related companies will be able to increase the usage of SoLoMo services by differentiating their own strategies with these factors influencing on SoLoMo services.