• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.7 s.110
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• pp.673-683
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• 2006

In this paper, we investgate variation of phase and magnitude characteristics which become different as the variables of DGS are changed and propose the new method to easily decide the best optimum DGS pattern taking advantage of this trend. Generalized Chebyshev(GC) low pass filter(LPF) is designed by using DGS obtained from this method GC DGS LPF is more available for filter application than Chevyshev DGS LPF because GC LPF have parallel resonators as series circuits, therefore unlikely Chebyshev LPF, transform step of the series elements can be omitted. By using the proposed method, GC DGS LPF(N=5) and as a subject of comparison, conventional Chbyshev LPF(N=7) are designed and implementation. From the comparison of the measured data, we confirmed that the implemented GC DGS 5th order LPF have much better cutoff characteristics and reduce by 0.58 times size, on the other hand the stop bandwidth become widen about 1.57 times or more in comparison with the conventional Chevyshev 7th order LPF.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.292-299
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• 2015

An envelope elimination and restoration transmitter that uses a tri-level envelope encoding scheme is presented for improving the efficiency and linearity of the system. The proposed structure amplifies the same magnitude signal regardless of the input peak-to-average power ratio and reduces the quantization noise by spreading out the noise to the out-of-band frequency, resulting in the enhancement of power efficiency. An improved linearity is also obtained by providing a new timing mismatch calibration technique between the envelope and phase signal. Implementation in a 130 nm CMOS process, transmitter measurements on a 20-MHz long-term evolution input signal show an error vector magnitude of 3.7 % and an adjacent channel leakage ratio of 37.5 dBc at 2.13 GHz carrier frequency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.527-536
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• 2000

This paper discusses the design of self-oscillating mixer type low noise down converter using the microwave field effect transistor. The mixer is consists of local oscillator in which high stability dielectric resonator and band pass filter to get rid of spurious oscillation at intermediate frequency stage. The microstrip antenna was integrated in the same substrate which generate 12.3GHz and low noise amplifier was also added after antenna using 3 stage of high electron mobility transistors. The output frequency from the local oscillator was chosen as 11.3GHz for the Ku-band application. The measured phase noise was -804dBc/Hz at 100kHz offset frequency, and the gain was 7～12dB in frequency range from 12.0GHz to 12.7GHz. The noise figure at intermediate frequency stage was 64H. The designed model shows less conversion loss than previous diode type mixer. The proposed mixer can be used in digital satellite broadcasting and communication system and expected to use in next generation low noise block design.

• Journal of Korean Public Health Nursing
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• v.21 no.2
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• pp.193-205
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• 2007

Purpose: To evaluate the current status of utilization and implementation of health promotion programs for Korean middle-aged women in public health centers. Methods: Three-phase stratified sampling was done to select 1304 middle-aged women (aged 40-64 years) from all regions of Korea. The data were collected by face-to-face interviews using a structured questionnaire for individual responses and mailed surveys to 126 public health centers. Descriptive statistics and $x^2$-test were done for data analysis. Results: Only 12 of the 126 public health centers (9.9%) implemented health promotion programs for middle-aged women, with the lack of manpower being cited as the main reason for the absence of programs. From individual responses, 11.3% had participated in health promotion programs offered by public health centers. The main reasons for not participating were inconvenient times and lack of information. Significant differences were found in the frequency of participation in programs, exercise programs and diabetes management according to the size of region. The majority of the respondents cited the need for medical services, followed by programs focused on stroke prevention and leisure time management. The responses on the willingness to participate followed a similar pattern. Conclusion: There are gaps between the utilization of health promotion programs by middle-aged women and what is offered by public health centers. The results of this study support the need to develop more health promotion programs focusing specifically on the needs of middle-aged women.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.5
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• pp.565-570
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• 2015

Spread spectrum communications have increased interest due to their immunity to channel fading and low probability of intercept. One of the limitations of the traditional digital spread spectrum systems is the need for spreading code synchronization. Chaotic communication is the analogue alternative of digital spread spectrum systems beside some extra features like simple transceiver structures. In this paper, This paper was used instead of the digital modulation and demodulation carriers for use in the chaotic signal in a digital communication system among the chaotic modulation schemes, the Differential Chaos Shift Keying(DCSK) is the most efficient one because its demodulator detects the data without the need to chaotic signal phase recovery. Also Implementation of Differential Chaos Shift Keying Communication System Using Matlab/Simulink and the receiver con decode the binary information sent by the transmitter, performance curves of DCSK are given in terms of bit-error probability versus signal to noise ratio with spreading factor as a parameter and we compare it to BPSK modulation.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.4
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• pp.595-601
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• 2011

This study proposed the system to automatically control the optimized raising environment for vegetation, raised in an equipment house, in which u-IT agricultural technology concept was applied. The system consists of environment sensors such as temperature, humidity, etc., biosensors such as EC, PH, etc., and requested automatic control devices, in which they were automatically controlled by the software system. The system is established in client systems, installed in each equipment house and the server system, collecting data from each client system as well. In addition, the system collects each farmer's data through the Internet and 3G network. In this phase, collected raising environment data comes to be analyzed in order to find out the optimized vegetation raising environment, finally, which is visualized and used for consulting each farmer.

• Journal of Advanced Navigation Technology
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• v.20 no.4
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• pp.292-297
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• 2016

Since continuous descent operations (CDO) is one of several tools available to aircraft operators and air navigation service providers (ANSPs) to increase safety, flight predictability, and airspace capacity while reducing noise, controller-pilot communications, fuel burn and emissions, widespread implementation of CDO would result in significant reductions in the environmental impact and aircraft operation costs in south korea as well. After analyzing each procedure from standard terminal arrival routes used for the Incheon international airport, it can be noticed that one of the procedures has a relatively high altitude constraint at initial approach fix than others, which lead the pilots to use unnecessary drag device in certain situations. Therefore we came to a conclusion that some arrival procedures need to be revised, so unnecessary procedure required during approach can be minimized, thereby reducing fuel consumption, noise and emissions compared to current approach procedures. And it is going to increase the safety margin significantly during approach phase due to reduced workload.

• The KIPS Transactions:PartD
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• v.10D no.3
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• pp.547-558
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• 2003

From the viewpoint of that music melody has the similar features to time-series data, music melody is transformed to a time-series data with normalization and corrections and the similarity between melodies is defined as the Euclidean distance between the transformed time-series data. Then, based the similarity between melodies of a music object, melodies are clustered and the representative of each cluster is extracted as one of theme melodies for the music. To construct the theme melody index, a theme melody is represented as a point of the multidimensional metric space of M-tree. For retrieval of user's query melody, the query melody is also transformed into a time-series data by the same way of indexing phase. To retrieve the similar melodies to the query melody given by user from the theme melody index the range query search algorithm is used. By the implementation of the prototype system using the proposed theme melody index we show the effectiveness of the proposed methods.

• Journal of Korean Society of Rural Planning
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• v.22 no.4
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• pp.71-80
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• 2016

Meanwhile, reference evapotranspiration(ET0) is important information for agricultural management including irrigation planning and drought assessment, the database of reference evapotranspiration for future periods was rarely constructed especially at districts unit over the country. The Coupled Model Intercomparison Project Phase 5 (CMIP5) provides several meteorological data such as precipitation, average temperature, humidity, wind speed, and radiation for long-term future period at daily time-scale. This study aimed to build a database for reference evapotranspiration using the climate forecasts at high resolution (the outputs of HadGEM3-RA provided by Korea Meteorological Administration (KMA)). To estimate reference evapotranspiration, we implemented four different models such as FAO Modified Penman, FAO Penman-Monteith, FAO Blaney-Criddle, and Thornthwaite. The suggested database system has an open architecture so that user could add other models into the database. The database contains 5,050 regions' data for each four models and four Representative Concentration Pathways (RCP) climate change scenarios. The developed database system provides selecting features by which the database users could extract specific region and period data.

• Journal of Broadcast Engineering
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• v.7 no.3
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• pp.248-261
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• 2002

In this paper, we proposed a new 3-dimensional(3-D) object-tracking algorithm that can control a stereo camera using a variable window mask supported by which uses ,B-D information and an optical BPEJTC. Hence, three-dimensional information characteristics of a stereo vision system, distance information from the stereo camera to the tracking object. can be easily acquired through the elements of a stereo vision system. and with this information, we can extract an area of the tracking object by varying window masks. This extractive area of the tracking object is used as the next updated reference image. furthermore, by carrying out an optical BPEJTC between a reference image and a stereo input image the coordinates of the tracking objects location can be acquired, and with this value a 3-D object tracking can be accomplished through manipulation of the convergence angie and a pan/tilt of a stereo camera. From the experimental results, the proposed algorithm was found to be able to the execute 3-D object tracking by extracting the area of the target object from an input image that is independent of the background noise in the stereo input image. Moreover a possible implementation of a 3-D tele-working or an adaptive 3-D object tracker, using the proposed algorithm is suggested.