• Journal of the Korean Society of Food Culture
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• v.23 no.3
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• pp.410-419
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• 2008

The objective of this study was to investigate the consumption pattern of snacks-containing trans-fatty acid in adolescents living in the Kwang-ju area of Korea, and to analyze the relevance toward their eating behaviors, body composition, nutrient intakes, and consumption frequency of snacks-containing trans fatty acid. A survey questionnaire was developed in order to investigate general environmental factors, eating behavior, nutritional knowledge, and the consumption frequency of snacks-containing trans fatty acid. A total of 312 middle school students were surveyed. The collection rate was 97% and ultimately 282 cases were analyzed. Anthropometric measurements, body composition data, and nutrient intakes were also collected. The consumption frequencies for snacks-containing trans-fatty acid were negatively correlated with food behavior scores (p<0.01) however, pocket money and snack intake frequency per day were positively correlated with consumption frequency. Also, snack consumption frequency had some correlation with the subjects' anthropometric measurements and body composition data such as total body water (p<0.01), body protein (p<0.01), body minerals (p<0.01), and skeletal muscle mass (p<0.01). Finally, the consumption frequency of snacks-containing trans fatty acid was significantly correlated with calcium intake (p<0.05), it also showed correlations with vitamin A, retinol, ${\beta}-carotene$, and folic acid intake, although statistical significance was not verified.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1312-1320
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• 2017

Recently, vector map data is developed and used in many domains widely. In the most cases, vector map data contains confidential information which must be kept away from unauthorized users. Moreover, the production process of vector maps is considerably complex and consumes a lot of money and human resources. Therefore, the secured storage and transmission are necessary to prevent the illegal copying and distribution from hacker. This paper presents a selective encryption algorithm using geometric objects in frequency domain for vector map data. In the proposed algorithm, polyline and polygon data in vector map is the target of the selective encryption process. Experimental results verified that proposed algorithm is effectively and adaptive the requirements of security.

• ETRI Journal
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• v.30 no.2
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• pp.275-281
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• 2008

A 40 Gb/s clock and data recovery (CDR) module for a fiber-optic receiver with improved phase-locked loop (PLL) circuits has been successfully implemented. The PLL of the CDR module employs an improved D-type flip-flop frequency acquisition circuit, which helps to stabilize the CDR performance, to obtain faster frequency acquisition, and to reduce the time of recovering the lock state in the event of losing the lock state. The measured RMS jitter of the clock signal recovered from 40 Gb/s pseudo-random binary sequence ($2^{31}-1$) data by the improved PLL clock recovery module is 210 fs. The CDR module also integrates a 40 Gb/s D-FF decision circuit, demonstrating that it can produce clean retimed data using the recovered clock.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.148-151
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• 2005

This paper proposes a high speed interface using redundant multi-valued logic for high speed communication ICs. This circuit is composed of encoding circuit that serial binary data are received and converted into parallel redundant multi-valued data, and decoding circuit that convert redundant multi-valued data to parallel binary data. Because of the multi-valued data conversion, this circuit makes it possible to achieve higher operating speeds than that of a conventional binary logic. Using this logic, a 1:4 demultiplexer (DEMUX, serial-parallel converter) IC was designed using a 0.35${\mu}m$ standard CMOS Process. Proposed demultiplexer is achieved an operating speed of 3Gb/s with a supply voltage of 3.3V and with power consumption of 48mW. Designed circuit is limited by maximum operating frequency of process. Therefore, this circuit is to achieve CMOS communication ICs with an operating speed greater than 3Gb/s in submicron process of high of operating frequency.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.3-6
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• 2006

There are three types of frequency-domain loop-loop EM induction method, depending on the loop separation and their location relative to the ground surface: horizontal-loop EM (HLEM), fixed small-loop EM, and helicopter-borne EM (HEM) methods. Multidimensional inversion provides tomographic images of the subsurface resistivity structure and thus enhances the interpretational accuracy of loop-loop EM data. HLEM method is shown to be effective for exploring groundwater resources in weathered and fractured crystalline basement terrains in semi-arid regions. Also, HEM method is useful for locating weak zones in landslide areas. The applicability of inversion to small-loop EM data depends solely on the S/N ratio. The quadrature response of small-loop EM data can only give the equivalent conductivity of a homogenous half-space model, and thus the in-phase component is essential in inverting EM data. However, the in-phase response is much lower and decreases more rapidly with decreasing frequency than the quadrature response. Further work is needed to obtain conductivity-depth images from small-loop EM data.

• Communications for Statistical Applications and Methods
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• v.25 no.4
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• pp.431-442
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• 2018

This paper highlights the computational explosion issues in the autoregressive moving average approach of frequency estimation of sinusoidal data with a large sample size. A new algorithm is proposed to circumvent the computational explosion difficulty in the conditional least-square estimation method. Notice that sinusoidal pattern can be generated by a non-invertible non-stationary autoregressive moving average (ARMA) model. The computational explosion is shown to be closely related to the non-invertibility of the equivalent ARMA model. Simulation studies illustrate the computational explosion phenomenon and show that the proposed algorithm can efficiently overcome computational explosion difficulty. Real data example of sunspot number is provided to illustrate the application of the proposed algorithm to the time series data exhibiting sinusoidal pattern.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2001.06a
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• pp.43-48
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• 2001

Many applications in the areas of agricultural, hydrological and environmental resource management require data over very large areas and with a high imaging frequency - monitoring crop growth, water stress, seasonal wetland flooding and natural vegetation development. This precludes the use of fine resolution data (Landsat, Spot) on the grounds of cost, accessibility and low imaging frequency. Meteorological satellites have the potential to fill this need, given their very wide spatial coverage, and high repeat imaging. The Remote Sensing Unit (RSU) at the Zambia Meteorological Department routinely receives, processes and archives imagery from both Meteosat and NOAA AVHRR satellites. Here I wish to present some examples of applications of these data sets that arise from the RSU work - relationships between rainfall and vegetation development as assessed by satellite, derived information and seasonal patterns of flooding in the Barotse floodplain and the Kafue flats. I also wish to outline ways in which a more widespread use of this data by the Zambian institutions canbe achieved.

• Journal of the Korean Data and Information Science Society
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• v.15 no.3
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• pp.655-662
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• 2004

In this paper, we assume that strengths of two components system follow a type II bivariate Pareto model with bivariate type I censored data. And these two components are subjected to a common stress which is independent of the strengths of the components. We obtain estimators for the system reliability based on likelihood function and relative frequency, respectively. Also we construct approximated confidence intervals for the reliability based on maximum likelihood estimator and relative frequency estimator, respectively. Finally we present a numerical study.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.167-172
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• 2007

The frequency-domain small-loop electromagnetic (EM) instruments are increasingly used for shallow environmental and geotechnical surveys because of their portability and speed. However, it is well known that the data quality is generally so poor that quantitative interpretation of the data is not justified in many cases. We present an inversion method that allows the correction for the calibration errors and also constructs multidimensional resistivity models. The key point in this method is that the data are collected at least at two different heights. The forward modeling used in the inversion is based on an efficient 3-D finite-difference method, and its solution was checked against 2-D finite-element solution. The synthetic and real data examples demonstrate that the joint inversion recovers reliable resistivity models from multi-frequency data severely contaminated by the calibration errors.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.998-1007
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• 2018

The advent of Wireless Sensor Networks (WSN) has led to their use in numerous applications. Sensors are autonomous in nature and are constrained by limited resources. Designing an autonomous topology with criteria for economic and energy conservation is considered a major goal in WSN. The proposed honey-hive clustering consumes minimum energy and resources with minimal transmission delay compared to the existing approaches. The honey-hive approach consists of two phases. The first phase is an Intra-Cluster Min-Max Discrepancy (ICMMD) analysis, which is based on the local honey-hive data gathering technique and the second phase is Inter-Cluster Frequency Matching (ICFM), which is based on the global optimal data aggregation. The proposed data aggregation mechanism increases the optimal connectivity range of the sensor node to a considerable degree for inter-cluster and intra-cluster coverage with an improved optimal energy conservation.