• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.6
• /
• pp.1163-1170
• /
• 2016

A hardware implementation of ultra-lightweight block cipher algorithm PRESENT which was specified as a standard for lightweight cryptography ISO/IEC 29192-2 is described. The PRESENT crypto-processor supports two key lengths of 80 and 128 bits, as well as four modes of operation including ECB, CBC, OFB, and CTR. The PRESENT crypto-processor has on-the-fly key scheduler with master key register, and it can process consecutive blocks of plaintext/ciphertext without reloading master key. In order to achieve a lightweight implementation, the key scheduler was optimized to share circuits for key lengths of 80 bits and 128 bits. The round block was designed with a data-path of 64 bits, so that one round transformation for encryption/decryption is processed in a clock cycle. The PRESENT crypto-processor was verified using Virtex5 FPGA device. The crypto-processor that was synthesized using a $0.18{\mu}m$ CMOS cell library has 8,100 gate equivalents(GE), and the estimated throughput is about 908 Mbps with a maximum operating clock frequency of 454 MHz.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.11 no.1
• /
• pp.73-79
• /
• 2017

It is difficult to detect the adult hearing loss after the language acquisition because of its slow progression, which can be evaluated voluntarily and actively when the appropriate tools are provided. Smartphones are one of useful tools, and they can utilize surveys and/or applications for hearing screening. This study aims to verify the possibility as a tool discovering delayed acquired hearing losses by comparing the pure tone screening application (app_PTS) which was recently developed by our research team and hearing handciap inventory (HHI). The subjects were 22 people whose age ranges from 10s to 80s. For pure tone averages (PTAs), hearing threshold level was selected the best one in same frequency, in both ears. Sensitivity and specificity of HHI were confirmed based on self awareness of hearing loss and PTAs at 1, 2, 4 kHz. Comparisons of two tests were measured by analyzing simple regression of correlation between PTAs of App_PTS and HHI scores. Sensitivity and specificity were 1.000 in both criteria. There was a statistically significant relationship between the PTAs_4 kHz and HHI (R-square = .951, p = .000). Hearing screening by questionnaire showed high correlation with smart phones based on application. Therefore, it can be useful as a hearing screening tool for individual life cycle using an user-friendly tool.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.6
• /
• pp.57-65
• /
• 2007

This paper presents the design of single phase PFC(Power Factor Correction) using a DSP(TMS320F2812). In order to realize the proposed boost PFC converter in average current mode control, the DSP requires the A/D sampling values for a line input voltage, a inductor current, and the output voltage of the converter. Because of a FET switching noise, these sampling values contain a high frequency noise and switching ripple. The solution of A/D sampling keeps away from the switching point. Because the PWM duty is changed from 5% to 95%, we can#t decide a fixed sampling time. In this paper, the three A/D converters of the DSP are started using the prediction algorithm for the FET ON/OFF time at every sampling cycle(40 KHz). Implemented A/D sampling algorithm with only one timer of the DSP is very simple and gives the autostart of these A/D converters. From the experimental result, it was shown that the power factor was about 0.99 at wide input voltage, and the output ripple voltage was smaller than 5 Vpp at 80 Vdc output. Finally the parameters and gains of PI controllers are controlled by serial communication with Windows Xp based PC. Also it was shown that the implemented PFC converter can achieve the feasibility and the usefulness.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.18 no.2
• /
• pp.28-32
• /
• 2014

Purpose Patient motion during myocardial perfusion SPECT can produce images that show visual artifacts and perfusion defects. This artifacts and defects remain a significant source of unsatisfactory myocardial perfusion SPECT. Motion correction has been developed as a way to correct and detect the patient motion for reducing artifacts and defects, and each motion correction uses different algorithm. We corrected simulated motion patterns with several motion correction methods and compared those images. Materials and Methods Phantom study was performed. The anthropomorphic torso phantom was made with equal counts from patient's body and simulated defect was added in myocardium phantom for to observe the change in defect. Vertical motion was intentionally generated by moving phantom downward in a returning pattern and in a non-returning pattern throughout the acquisition. In addition, Lateral motion was generated by moving phantom upward in a returning pattern and in a non-returning pattern. The simulated motion patterns were detected and corrected similarly to no-motion pattern image and QPS score, after Motion Detection and Correction Method (MDC), stasis, Hopkins method were applied. Results In phantom study, Changes of perfusion defect were shown in the anterior wall by the simulated phantom motions, and inferior wall's defect was found in some situations. The changes derived from motion were corrected by motion correction methods, but Hopkins and Stasis method showed visual artifact, and this visual artifact did not affect to perfusion score. Conclusion It was confirmed that motion correction method is possible to reduce the motion artifact and artifactual perfusion defect, through the apply on the phantom tests. Motion Detection and Correction Method (MDC) performed better than other method with polar map image and perfusion score result.

• Korean Journal of Environmental Biology
• /
• v.17 no.4
• /
• pp.379-387
• /
• 1999

During the past several decades, electricity generating plant increased with remarkable rapidity in Korea. Recently the increase has been much more rapid as the rate of industrialization has accelerated. Construction of nuclear power plants in coastal areas inevitably caused the perturbation of critical coastal habitats and thus influenced marine algal species composition. Particularly, an increase in the building of nuclear power plants led the amounts of heat discharged to increase exponentially. As far as the effects of cooling water and thermal discharges are concerned, benthic marine algae are likely to be vulnerable to a discharge. Heated effluents from nuclear power plants, with the temperature rises of 7~12$^{\circ}C$ under normal operating and design conditions, are discharged through the discharge canal and into natural water bodies. It is clear that the characteristic marine algal community is developed in the area affected by the thermal discharges; i.e. low species richness and low species diversity. Nevertheless, it is worthwhile to note that elevated temperatures exert differential effects depending on the algal populations. Benthic marine algae grown at the discharge canal can be regarded as warm tolerant species. 35 species (4 blue-green, 9 green, 8 brown and 14 red algae) of marine algae occurred more than 20eye frequency at discharge canal of three nuclear power plants in the east coast during 1992 ~ 1998 and thus can be categorized as warm tolerant species in Korea. To minimize the ecological impacts of waste heat on benthic marine algae, it is recommended that, in the future, nuclear power plants will have to employ some form of closed-cycle cooling for the condensers.

• Korean Journal of Environmental Agriculture
• /
• v.27 no.3
• /
• pp.231-238
• /
• 2008

This study proposed the method of phosphate recovery from municipal wastewater by using ferrous iron waste, generated from the mechanical process in the steel industry. In the analysis of XRD, ferrous iron waste was composed of $Fe_3O_4$ (magnetite), practically with $Fe^{2+}$ and $Fe^{3+}$. It had inverse spinel structure. In order to identify the adsorption characteristic of phosphate on ferrous iron waste, isotherm adsorption test was designed. Experimental results were well analyzed by Freundlich and Langmuir isotherm theories. Empirical constants of all isotherms applied increased with alkalinity in the samples, ranging from 1.2 to 235 $CaCO_3/L$. In the regeneration test, empirical constants of Langmuir isotherm, i.e., $q_{max}$ (maximum adsorption capacity) and b (energy of adsorption) decreased as the frequency of regeneration was increased. Experiment was further performed to evaluate the performance of the treatment scheme of chemical precipitation by ferrous iron waste followed by biological aerated filter (BAF). The overall removal efficiency in the system increased up to 80% and 90% for total phosphate (TP) and soluble phosphate (SP), respectively, and the corresponding effluent concentrations were detected below 2 mg/L and 1 mg/L for TP and SP, respectively. However, short-circuit problem was still unsolved operational consideration in this system. The practical concept applied in this study will give potential benefits in achieving environmentally sound wastewater treatment as well as environmentally compatible waste disposal in terms of closed substance cycle waste management.

• Research in Community and Public Health Nursing
• /
• v.13 no.2
• /
• pp.354-362
• /
• 2002

Objectives: This study was conducted to examine the relationships among perceived life stress, self-esteem, and depression in middle-aged women. Methods: Data were collected from March 30 to May 25, 2000. The study subjects were 123 middle-aged women living in Pusan. The instruments used for this study were the Perceived Life Stress scale developed by Lee (1984), based on the original scale designed by Yu, et al. (1994), Self-esteem scale developed by Rho, et al. (1997), and the Depression scale developed by Ahn (1988). For data analysis, the SPSS PC+ was utilized, by which frequency and percentage, mean and standard deviation, t-test, ANOVA, Sheffe's test and Pearson's correlation coefficients were examined. The reliability of the instruments were tested by Cronbach's $\alpha$, showing the internal consistency of 0.7328 for the self-esteem scale. and 0.8987 for the depression scale. Results: 1) The results showed a relatively low perceived life stress score in the middle-aged women with a mean and standard deviation of 363.18 and 72.92 (range: .00 - 1877.38). 2) The results showed a relatively high self-esteem score in the middle-aged women with a mean and standard deviation of 29.77 and 5.06 (range: 10 - 40). 3) The results showed a relatively high depression score in the middle-aged women with a mean and standard deviation of 39.46 and 9.38 (range: 0 - 61). 4) There were no statistically significant differences in perceived life stress by demographic related factors. 5) There were statistically significant differences in self-esteem by health status (F=8.930, p= .000) and economic status (t=4.792, p= .010). 6) There were statistically significant differences in depression by age (F=3.770, p= .0261). education (F=4.850, p= .003) and regularity of menstrual cycle (F=13.180, p= .000). 7) There was no statistically significant correlation between perceived life stress, and self-esteem in the middle-aged women (r=-.077, p= .399). 8) There was no significant correlation between perceived life stress. and depression in the middle-aged women (r= .010, p= .916). 9) There was a significant negative correlation between self-esteem, and depression in the middle-aged women (r=- .359, p= .000). Conclusion: Higher self-esteem was related to a lower depression status. Therefore, it is necessary to elevate the level of self-esteem in order to reduce the level of depression in middle-aged Korean women.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.9 no.3
• /
• pp.137-152
• /
• 2004

The climatological characteristics of coastal zone over the southwestern coast of Korea peninsula were investigated using the data observed by AWS (automatic weather system) and 4 buoy points. Coastal zone is climatologically defined as the region bounded by the distinct contrast of temperature gradient and wind speed across coastline. In the southwest of peninsula four cross-lines consisted of AWS aligned with each buoy were selected as Geojedo buoy line, Geomundo buoy line, Chilbaldo buoy line and Dukjukdo buoy line. Analysis on the diurnal cycle and intra-month variation, monthly mean and maximum value, the temperature gradient with distance between buoy and each station and the accumulative frequency of wind speed were applied to find out the characteristics and the range of coast zone. The maximum ranges of coastal zone vary from offshore to Sanglim (about 34 km distance from coastline) for Geojedo buoy line, to Sunchun (about 52 km) for Geo-mundo buoy line, to Jaeundo (about 27 km) for chilbaldo buoy line and to Yongin (about 65 km) for Dukjukdo buoy line. The modification of coastal zone according to synoptic flow was investigated for the onshore, off-shore and calm cases. The ranges of coastal zone are significantly changed with the distance between 65∼90 km for the case of onshore. In addition, we tried to find out the variation of the wind and temperature and the wind ratio of wind speed at ocean to land stations along Geojedo buoy line during 12∼13 Sep. 2003 affected by typhoon (MAEMI).

• Journal of Korean society of Dental Hygiene
• /
• v.12 no.2
• /
• pp.379-389
• /
• 2012

Objectives : The purpose of this study was to improve the practice level on dental hygienists'infection prevention by examining the actual condition of dental hygienists'infection control and analyzing factors of having influence upon this. Methods : A questionnaire survey was carried out from July 18, 2011 to August 26 targeting dental hygienists who work at medical institutions where are located in Daegu, Busan and Ulsan Metropolitan Cities and Gyeongsangnam buk-do. After then, the following conclusions were obtained. Results : 1. As a result of surveying practice by item in the practice level of infection prevention, the items with high practice level in the management of infectious diseases were surveyed to be 12 months(89.6%) for health-checkup cycle and to be having experience of vaccination(78.0%) for hepatitis type B. The items with high practice level in the management and practice of washing hands were indicated to be in order of regularly paper towel(87.7%) and hands cleaning after regular medical examination(80.5%). In the item of the practice on wearing and managing individual protection equipment, regularly wearing(93.1%) rubber globes given washing implements was indicated to be high. 2. As a result of analyzing working career, working institution, working region, and practice level of infectious-disease management, the appearance of fulfilling infection control guidelines at medical institution and the experience of education for infection control were indicated to have difference depending on working institution. Regularly health checkup was indicated to have difference depending on respondents' working career and working institution. 3. The whole average in the practice level of infection prevention according to working career, working institution, and working region was indicated to be 2.55 out of 3-point perfection. 4. Wearing latex gloves was indicated to have statistically significant difference depending on working institution(p<0.001) and working region(p<0.001). The exchange of latex gloves every patient and the use of paper apron had statistically significant difference depending on working region(p<0.001). 5. As a result of comparing the frequency of using protection equipment for preventing infection according to the management of infectious diseases, the statistically significant difference was shown depending on the appearance of infection control guidelines at medical institution(p<0.001), the appearance of having experience of health checkup(p<0.01), and the appearance of having experience of vaccination for hepatitis type B(p<0.05). Conclusions : The above-mentioned findings showed that the denture satisfaction of the denture-wearing senior citizens was linked to their subjective oral health awareness. Therefore it will be possible to improve denture-wearing elderly people's quality of life when oral health plans geared toward boosting their denture satisfaction are carried out.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.4 no.1
• /
• pp.25-32
• /
• 2006

This study examined the possibility of using dark-striped field mice as a biological indicator for the environmental radio-surveillance. For this study, dark-striped field mice were caught from five areas of Kyonggi, Kyongsang, Chungchong and Cholla provinces. The external morphological characteristics and isoenzymic types of dark-striped field mice were studied after they were captured. Among the external morphological characteristics, the dark-brown coat, dark back stripe, head-to-tail length, tail length, and ear length matched the taxonomical characteristics of dark-striped field mice. The analyses on L-lactate dehydrogenase, aspartate aminotransferase, and malate dehydrogenese revealed that one species of dark-striped field mice, called Apodemus agrarius, was inhabitated throughout a wide range of Korea. On the other hand, the frequency of micronuclei in peripheral polychromatic erythrocytes to survived mice after irradiation also analyzed. The LD50/30 of A. cgrarius and ICR mice were approximately 5 Gy and 7.9Gy, respectively. The results of the study reveal that wild A. asrarius have a high potential as a biological monitoring system to determine the impact of radiation in areas such as those within the vicinity of nuclear power plants.