• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.2
• /
• pp.53-59
• /
• 2012

Smart phones are very convenient for communication, but you need to not to forget to change to silent mode when you go to church or cinema. Many people used to forget changing their cell phones to silent mode. In this paper, we have developed an android smart phone app. for automatic changing silent mode, which exploited smart phones' GPS and computing capability. According to the GPS location data and time, this app. will automatically change a cell phone to silent mode. We believe that this app. would provide us a lot of convenience.

• ETRI Journal
• /
• v.33 no.6
• /
• pp.953-956
• /
• 2011

A novel dual-mode bandpass filter (BPF) using a dual spiral-shaped defected ground waveguide (DGW) resonator is proposed in this letter. The dual-mode characteristic of this filter is achieved by loading a defected T-shaped stub at the midline of the spiral-shaped DGW resonator. Also, non-orthogonal input and output feed-lines are adopted in the filter. Based on the compact DGW structure, a dual-mode BPF with central frequency of 1.5 GHz for the global positioning system is designed, fabricated, and measured. Measured results agree well with the predicted response and verify the proposed methodology.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.4
• /
• pp.767-773
• /
• 2017

In this paper, we propose a design of Intra prediction angular mode decision for HEVC encoder. Intra prediction coding of HEVC is a method for predicting a current block by referring to samples reconstructed around a current block. Intra prediction supports a total of 35 modes with 1 DC mode, 1 Planar mode, and 33 Angular modes. Intra prediction coding of HEVC works by performing all 35 modes for efficient encoding. However, in order to process all of the 35 modes, the computational complexity and operational time required are high. Therefore, this paper proposes comparing the difference in the value of the original pixel, using an algorithm that determines angular mode efficiently. This new algorithm reduces the Hardware size. The hardware which is proposed was designed using Verilog HDL and was implemented in 65nm technology. Its gate count is 14.9K and operating speed is 2GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.10 no.3
• /
• pp.351-358
• /
• 1999

This paper describes the mode identification of resonant frequencies in dielectric loaded circular cylindrical cavity. To identify the mode of resonant frequencies, the calculated resonant frequencies were compared with the simulated ones in the air-filled circular cylindrical cavity by Microstripes EM simulator. With z-oriented magnetic field excitation, we could get only TE mode resonance, while all the modes including TM mode were observed with $\phi$-oriented magnetic field excitation. We could identify the modes with the two excitation methods. We applied the identification method to a dielectric loaded circular cylindrical cavity and compared these results with experimental ones. To certify the method, we traced resonance frequencies with varying the dielectric height. We observed that the resonance of $TE_{011}$ mode was changed dramatically while the variation of the $TE_{111}$ and $TE_{211}$ modes are relatively small.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.2
• /
• pp.19-25
• /
• 2008

When there are numerous wireless communication systems co-existing in the limited available frequency resource, an unexpected time delay can be caused during the system switching. So, in order to reduce this time delay, a mode selection method is required. In this paper, we propose a mode selection method to minimize the time delay for multi-system wireless communication systems. For the sake of efficiency, the mode selection method is designed by analyzing the preamble characteristics of different standards. Instead of performing a full search, we propose the preamble partial search to reduce the time delay to a minimum. Simulated with Matlab in an additive white Gaussian noise(AWGN) environment with a signal to noise ratio(SNR) of 10dB and bit error rate(BER) of $10^{-6}$, we evaluated and showed the performance improvement gained by using our proposed mode selection method.

• Proceedings of the Korea Society of Design Studies Conference
• /
• 2001.10a
• /
• pp.36.1-36
• /
• 2001

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.7
• /
• pp.1445-1451
• /
• 2005

Home-Network is an integrated network of the PC and all electric home appliances in the home so that they can communicate with each other. In the 21th century, here are various technology for Home Network environment such as HomePNA, IEEE 1394, Ethernet Lan and Bluetooth. For Home Network construction, generally, the standard series interface 'RS232' is used to make communication possible between electric home appliances. However Home network using RS232 has a problem. That is, All machines have to be connected to each other with RS232 using Point-to-Point mode. In this case, the system becomes complicated because we have to use circuits as much as there are machines and increased expenses. To improve this problem, In this thesis, designed home network using RS422 Multi-drop mode serial communication and controled it with embedded linux system. And connected RS422 with motors and sensors using PIC to make the home network virtual environment.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.6
• /
• pp.777-788
• /
• 2014

This paper presents a wide output range, high power efficiency reconfigurable charge pump for driving touch panels with the high resistances. The charge pump is composed of 4-stages and its configuration automatically changes based on the required output voltage level. In order to keep the power efficiency over the wide output voltage range, internal blocks are automatically activated or deactivated by the clock driver in the reconfigurable charge pump minimizing the switching power loss due to the On and Off operations of MOSFET. In addition, the leakage current paths in each mode are blocked to compensate for the variation of power efficiency with respect to the wide output voltage range. This chip is fabricated using $0.18{\mu}m$ BCD process with high power MOSFET options, and the die area is $1870{\mu}m{\times}1430{\mu}m$. The power consumption of the charge pump itself is 79.13 mW when the output power is 415.45 mW at the high voltage mode, while it is 20.097 mW when the output power is 89.903 mW at the low voltage mode. The measured maximum power efficiency is 84.01 %, when the output voltage is from 7.43 V to 12.23 V.

• Journal of Korean Academic Society of Home Health Care Nursing
• /
• v.26 no.3
• /
• pp.278-287
• /
• 2019

Purpose: This study aims to examine the relationship between ego resilience, family resilience, and the perception of successful aging in nursing students; additionally, specific factors relating to the perception of successful aging were identified. Methods: The participants comprised 154 nursing students. Data were collected through the administration of self-reported questionnaires. Data analysis was then performed utilizing a t-test, an ANOVA, Pearson's correlation coefficients, and a multiple regression analysis. Results: Family resilience differed significantly based on the type of residence (p=.020) (i.e., living with grandparents (p=.048)). Perception of successful aging differed significantly based on grade (p<.001). The perception of successful aging showed a positive correlation relative to mode of communication and organizational pattern. The mode of communication accounted for 4.7% of perception of successful aging. Conclusion: The significance of the study on the importance of mode of communication was confirmed by identifying the effects of the perception of successful aging. Nursing students may actively cope with crises through communication; thus, successfully recognizing aging in order to lead a healthy life. Furthermore, having a high perception of successful aging while treating an increasing number of elderly patients at the clinical practice is believed to have a positive effect on patient care.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.3
• /
• pp.1301-1318
• /
• 2017

In order to utilize the licensed channel of cognitive radio (CR) when the primary user (PU) is detected busy, a benefit-exchange access mode based on cooperative communication is proposed to allow secondary user (SU) to access the busy channel through giving assistance to PU's communication in exchange for some transmission bandwidth. A holistic joint optimization problem is formulated to maximize the total throughput of CR system through jointly optimizing the parameters of cooperative spectrum sensing (CSS), including the local sensing time, the pre-configured sensing decision threshold, the forward power of cooperative communication, and the bandwidth and transmission power allocated to SUs in benefit-exchange access mode and traditional access mode, respectively. To solve this complex problem, a combination of bi-level optimization, interior-point optimization and exhaustive optimization is proposed. Simulation results show that, compared with the tradition throughput maximizing model (TTMM), the proposed holistic joint optimization model (HJOM) can make use of the channel effectively even if PU is busy, and the total throughput of CR obtains a considerable improvement by HJOM.