• Journal of Navigation and Port Research
• /
• v.30 no.1 s.107
• /
• pp.85-90
• /
• 2006

RFID(Radio Frequency IDentification) is appearing by point technology by Ubiquitous environment of new paradigm and Logistics' application But, RFID chip of this is high price and short bandwidth, low power and interference etc. can become technological problem This is getting into obstacle in common use. Reader and tag, Embedded software etc.. that are accomplishing standardization are imported paying most expensive royalty. This paper deals with a RFID cognition system that use PDA under ubiquitous environment to apply to Logistics system A RFID cognition system processes input/output of fundamental information attaching a tag onto products. And a RFID cognition system supports quick, correct and sqfe synthetic Logistics managerial system through construction of database. This can minimize logistics costs and improve the quality of customer service. A RFID cognition system has advantage that can widen range of application to area that cognition system of existent fixing style can not do. Also, it can expect economical effect through inexpensive system construction.

• The KIPS Transactions:PartC
• /
• v.15C no.6
• /
• pp.469-480
• /
• 2008

The recently proposed RFID(Radio Frequency Identification) authentication protocol based on a hash function can be divided into two types according to the type of information used for authentication between a reader and a tag: either a value fixed or one updated dynamically in a tag memory. In this paper, we classify the protocols into a static ID-based and a dynamic-ID based protocol and then analyze their respective strengths and weaknesses. Also, we define a new security model including forward/backward traceability, synchronization, forgery attacks. Based on the model, we analyze the previous protocols and propose a new dynamic-ID based RFID mutual authentication protocol. Our protocol provide enhanced RFID user privacy compared to previous protocols and identify a tag efficiently in terms of the operation quantity of a tag and database.

• Journal of KIISE
• /
• v.43 no.3
• /
• pp.296-303
• /
• 2016

Mobile real-time systems with limited system resources and a limited power source need to fully utilize the system resources when the workload is heavy and reduce energy consumption when the workload is light. EDZL (Earliest Deadline until Zero Laxity), a multiprocessor real-time scheduling algorithm, can provide high system utilization, but little work has been done aimed at reducing its energy consumption. This paper tackles the problem of DVFS (Dynamic Voltage/Frequency Scaling) in EDZL scheduling. It proposes a technique to compute a uniform speed on full-chip DVFS platforms and individual speeds of tasks on per-core DVFS platforms. This technique, which is based on the EDZL schedulability test, is a simple but effective one for determining the speeds of tasks offline. We also show through simulation that the proposed technique is useful in reducing energy consumption.

• Korean Journal of Community Nutrition
• /
• v.15 no.3
• /
• pp.342-350
• /
• 2010

This study investigates differences in middle school male students' anthropometric variables and dietary habits using BMI (Body Mass Index) classifications. $\chi^2$ -test for frequency and ANOVA test for mean value and duncan value were used to analyze results. Averaged results of three groups of middle school male students' anthropometry including height (normal group 164.4 cm, overweight group 165.0 cm, obese group 167.0 cm), weight (normal group 56.0 kg, overweight group 70.0 kg, obese group 83.2 kg) and waist circumference (normal group 20.7 cm, overweight group 79.8 cm, overweight group 89.6 cm) were resulted. Classification of obese group was based upon 2007 growth charts using BMI criteria. This study indicates the normal weight group boys have over-eating related dietary habits and the obese groups have less calorie dietary habits. They answered oppositely to normal recognition. The obese group reflected dietary problems, such as preferences for sweet fruit rather than normal group males. Dinnertime of the groups were significantly different and obese group's earlier dinnertime can influence on their late night snack eating. Forty precent of obese male group like fruits as late night eating food. Three meal amount of three groups were significantly different, as obese group answered they ate same amount at every meal. It can mean obese group ate more amount of food in every meal. Overweight and obese male students have dietary problem of fast eating and answers of unbalanced eating were higher in normal group. These could mean obese group eats well in every food and fast eating habit could lead a lot of food eating habit. Obese group chooses out-going food of less calorie and frequency of fast food eating was lower than normal group. In result, obese group answered that they have less calorie related dietary habits, it could mean their answers were false or fixed dietary habit. Therefore, more researches should be followed.

• The Journal of the Korean life insurance medical association
• /
• v.2 no.1
• /
• pp.182-194
• /
• 1985

Cholelithiasis, one of the digestive, disease is one of the subject to have to be solved in the medical field because it is very important health problem in clinic and gives people much pain. The formulative process of gall stone is not certainly known yet, but an approach to the size, location, bile sludge of gall ston and the existence of pus is very contributive to the cure and prediction of the disease. As above, the early diagnosis of gall stone is very important. A few study on the possessing rate of gall stone in normal Korean Group is reported. But no report has submitted to the Korean Life Insurance Medical Association until now. We, the Medical Dept. of Dae Han Kyouk Life Insurance Co. Ltd., practiced ultrasonic examination for the recent 17 months and obtained 84 data of gall stone potency out of 4201 examples. We analyzed them on the basis of sex, age, gall stone incidence rate and the results are as follows; 1) The possessing rate of gall stone in female showed 1.22 times higher than in in male. 2) The older the medical examined group grow, the more the frequency of gall stone incidence increase regardless of sex. 3) Our report coincides with foreign one in sex and age, but in total gall stone incident frequency our country has 2%, which is much less than foreign one.

• Earthquakes and Structures
• /
• v.10 no.5
• /
• pp.1143-1179
• /
• 2016

Offshore wind turbines are considered as a fundamental part to develop substantial, alternative energy sources. In this highly flexible structures, monopiles are usually used as support foundations. Since the monopiles are large diameter (3.5 to 7 m) deep foundations, they result in extremely stiff short monopiles where the slenderness (length to diameter) may range between 5 and 10. Consequently, their elastic deformation patterns under lateral loading differ from those of small diameter monopiles usually employed for supporting structures in offshore oil and gas industry. For this reason, design recommendations (API and DNV) are not appropriate for designing foundations for offshore wind turbine structures as they have been established on the basis of full-scale load tests on long, slender and flexible piles. Furthermore, as these facilities are very sensitive to rotations and dynamic changes in the soil-pile system, the accurate prediction of monopile head displacement and rotation constitutes a design criterion of paramount importance. In this paper, the Fourier Series Aided Finite Element Method (FSAFEM) is employed for the determination of static impedance functions of monopiles for OWT subjected to horizontal force and/or to an overturning moment, where a non-homogeneous soil profile has been considered. On the basis of an extensive parametric study, and in order to address the problem of head stiffness of short monopiles, approximate analytical formulae are obtained for lateral stiffness $K_L$, rotational stiffness $K_R$ and cross coupling stiffness $K_{LR}$ for both rough and smooth interfaces. Theses expressions which depend only on the values of the monopile slenderness $L/D_p$ rather than the relative soil/monopile rigidity $E_p/E_s$ usually found in the offshore platforms designing codes (DNV code for example) have been incorporated in the expressions of the OWT natural frequency of four wind farm sites. Excellent agreement has been found between the computed and the measured natural frequencies.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.7
• /
• pp.325-330
• /
• 2017

Bluetooth 4.0 is a technology suitable for the Internet of things that is used for communication between various devices. This technology is suitable for developing a service by combining with automobiles. In this study, a security authentication system was designed by linking Bluetooth 4.0 technology and a vehicle system as an implementation example of an object internet service. A procedure was designed for security authentication and an authentication method is proposed using a data server. When the security authentication function is provided, various additional services can be developed using the information collection function of the risk notification and user action history. In addition, BLE (Bluetooth Low Energy) technology, which is a wireless communication technology that enables low-power communication and low-power communication in the process of the standardization and development of Bluetooth technology and technology, improves the battery life through the use of RFID or NFC This study expanded the range possible. The security service can be extended by expanding the scope of authentication by the contactless type. Using the proposed system, a customized service can be provided while overcoming the problems of an existing radio frequency (RF)-based system, portability, and battery usage problem.

• Journal of Nutrition and Health
• /
• v.35 no.1
• /
• pp.115-123
• /
• 2002

This study was carried out to investigate the utilization status of internet dietary information by gender(boys: 363, girls: 366) in adolescent(middle & high school students). The results were summarized as follows. The internet using frequency of 6-7times per week had 45.0% of subjects and the using time of internet per a time was shown mainly'<2hours(68.5%)'. The main place for internet use was home(79.0%) and favorite search engine was 'Yahoo'(45.7%) and 'Daum'(19.3%). As main purpose using internet were mentioned 'social intercourse'(45.0%) and data search'(24.8%). The organization that offer to reliable internet information was educational institution'(49.4%). The problems in using information site were 'poor information'(26.4%), 'slow connection speed'(22.6%), and 'don't arouse interest'(18.8%). The search experience about dietary information had only 27.9% of subjects and search purpose was 'for homework'(33.3%) and 'for health'(32.0). The satisfaction degree of dietary information was not high. The connection motive to dietary information was mainly 'by site navigation casualty'(55.7%). Only 7.7% of subjects had experience of nutrition counseling using internet, and the motive of nutrition counseling was also 'by site navigation causally'(55.8%). The purpose of counseling was 'for diet'(41.5%) and 'for health problem'(30.2%), and the satisfaction degree of counseling result was very low. As the ask of improvement for counseling site were pointed out 'poor in answer content'(44.8%) and 'lazy answer'(31.0%). The subjects wanted to get the dietary information about 'growth in status'(41.4%), 'diet related skin beauty'(14.6%), the update period less 1 month, and the way of 'free board'(32.3%), 'game'(21.1%) and 'animation'(19.3%) as offer tool. The results of this study showed that although the internet using percent and frequency of subjects was high, they used dietary information very seldom and they are dissatisfied with internet nutritional information. Therefore, the information donor should consider which dietary information was needed and what is the optimal tool for adolescent.

• Smart Structures and Systems
• /
• v.15 no.4
• /
• pp.997-1018
• /
• 2015

Structural health monitoring along with damage detection and assessment of its severity level in non-accessible reinforced concrete members using piezoelectric materials becomes essential since engineers often face the problem of detecting hidden damage. In this study, the potential of the detection of flexural damage state in the lower part of the mid-span area of a simply supported reinforced concrete beam using piezoelectric sensors is analytically investigated. Two common severity levels of flexural damage are examined: (i) cracking of concrete that extends from the external lower fiber of concrete up to the steel reinforcement and (ii) yielding of reinforcing bars that occurs for higher levels of bending moment and after the flexural cracking. The purpose of this investigation is to apply finite element modeling using admittance based signature data to analyze its accuracy and to check the potential use of this technique to monitor structural damage in real-time. It has been indicated that damage detection capability greatly depends on the frequency selection rather than on the level of the harmonic excitation loading. This way, the excitation loading sequence can have a level low enough that the technique may be considered as applicable and effective for real structures. Further, it is concluded that the closest applied piezoelectric sensor to the flexural damage demonstrates higher overall sensitivity to structural damage in the entire frequency band for both damage states with respect to the other used sensors. However, the observed sensitivity of the other sensors becomes comparatively high in the peak values of the root mean square deviation index.

• The Journal of the Acoustical Society of Korea
• /
• v.34 no.3
• /
• pp.184-191
• /
• 2015

In this paper, a normal mode reverberation model for a range-independent environment of shallow water is proposed to calculate the reverberation level in the low-frequency range. Normal mode is used to calculate the acoustic energy propagating from the source to the scattering area and from the scattering area to the receiver. Each mode is decomposed into up and down going waves to consider scattering strength at the scattering area. The scattering functional form combines Lambert's law with a Gaussian-like term near the specular direction based on Kirchhoff approximation considering bottom condition. For verification of the suggested model, the result is relatively compared to several solutions of the problem XI and XV in the Reverberation Modeling Workshop I sponsored by the US Office of Naval Research.