• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6C
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• pp.295-304
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• 2012

In this study, a resonant column testing system which is the largest in Korea has been developed to evaluate the dynamic deformation characteristics of coarse granular geomaterials, and the performance and the applicability of the testing system have been verified. The system has been developed as a typical Stokoe type device whose boundary conditions are fixed bottom and free top with additional mass, and can adopt a large specimen with 200 mm in diameter and 400 mm in height. The driving and measurement instruments are configured as high performance and precision systems, hence the automated testing system is appropriate to drive enough stress and to measure the behavior precisely for the test in practical manner. The dynamic response of the mechanical components and the applicability of the system have been evaluated using metal specimens as well as polyurethane specimens, and its precision was verified by comparing its results with those from other equipment and/or methods. To confirm the applicability of the large system for coarse geomaterials, the resonant column test results from both large and normal scale apparatus for the same material were compared and it was found that the result can be partially affected by scale. Finally, the dynamic deformation characteristics of coarse geomaterial which is used for construction of large dam was evaluated using the large system and its practicality could be confirmed.

• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.63-69
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• 2014

For the safety messages in IEEE 802.11p vehicles network environment(WAVE), strict periodic beacon broadcasting requires status advertisement to assist the driver for safety. WAVE standards apply multiple radios and multiple channels to provide open public road safety services and improve the comfort and efficiency of driving. Although WAVE standards have been proposed multi-channel multi-radio, the standards neither consider the WAVE multi-radio environment nor its effect on the beacon broadcasting. Most of beacon broadcasting is designed to be delivered on only one physical device and one control channel by the WAVE standard. also conflict-free channel assignment of the fewest channels to a given set of radio nodes without causing collision is NP-hard, even with the knowledge of the network topology and all nodes have the same transmission radio. Based on the latest standard IEEE 802.11p and IEEE 1609.4, this paper proposes an interference aware-based channel assignment algorithm with Nash bargaining solution that minimizes interference and increases throughput with wireless mesh network, which is deigned for multi-radio multi-cahnnel structure of WAVE. The proposed algorithm is validated against numerical simulation results and results show that our proposed algorithm is improvements on 8 channels with 3 radios compared to Tabu and random channel allocation algorithm.

• Journal of the Korean GEO-environmental Society
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• v.19 no.8
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• pp.5-10
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• 2018

This study provides a method to assess the compressive strength of granitic gneiss using total sound signal energy, which is calculated from the signal of sound pressure measured when an object impacts on rock surface, and its results. For this purpose, many test specimens of granitic gneiss were prepared. Each specimen was impacted using a devised device (impacting a specimen by an initial rotating free falling and following repetitive rebound actions) and all sound pressures were measured as a signal over time. The sound signal was accumulated over time (called total sound signal energy) for each specimen of granitic gneiss and it was compared with the directly measured compressive strength of the specimen. The comparison showed that the total sound signal energy was directly proportional to the measured compressive strength, and with this result the compressive strength of granitic gneiss can be reliably assessed by an estimation equation of total sound signal energy. Furthermore, from the study results it is clearly believed that the compressive strength of other rocks and concrete can be assessed nondestructively using the total sound signal energy.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.2
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• pp.61-65
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• 2009

In this paper, we report on the growth and optical characteristics of white-LED without fluorescent material. The growth of DH(double heterostructure) with AlGaN active layer was performed on a n-GaN/(0001) $Al_{2}O_{3}$ by the mixed-source HVPE and multi-sliding boat. The CRI(color rendering index) of packaging device charged in the range 72-93 with CIE chromaticity coordinates(x=$0.26{\sim}0.34$, y=$0.31{\sim}0.40$). And CCT(correlated color temperature) values was measured $5126{\sim}10406K$ with increasing injection current. The CIE point of conventional phosphor white LED shifts blue region, but cm point of non-phosphor white LED shifts opposite direction. These results show the mixed-source HVPE can be possible to newly fabricate method of phosphor free white LED with high CRI value.

• Journal of Chest Surgery
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• v.18 no.2
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• pp.182-192
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• 1985

[here are so many reports that pulsatile blood flow provides physiologic organ perfusions during cardiopulmonary bypass. So, we compared the recent 30 cases undergoing cardiac surgery by Cobe-Stckert pulsatile roller pump with another 30 cases by Polystan nonpulsatile roller pump. Pulsatile flow was applied during aortic-cross clamping period when synchronized to internal EKG simulator, and perfusion mode was changed to continuous nonpulsatile flow after declamping of aorta. Age, sex, weight, and disease entities were comparable and operative techniques were similar between two groups. 1. There were no differences in average ACC time, ECC time, and Operation time. 2. Postoperative artificial respiration time was 6hrs 30mins in nonpulsatile group and 4hrs 48mins in pulsatile group, and detubation time after ventilator weaning was 2hrs 44mins in nonpulsatile group and 1hrs 43mins in pulsatile group. 3. Average pulse pressure was 8mmHg in nonpulsatile group and 55mmHg in pulsatile group, and a mean arterial pressure was 66.0mmHg in nonpulsatile group and 60.7mmHg in pulsatile group. 4. Mean urine-output during ACC;ECC period was 9.717.3;9.913.2ml/kg/hr in nonpulsatile group and 14.215.0;15.817.5 in pulsatile group [p<0, 05], and thereafter progressive decrease of differences in urine output between two groups until POD 2, and lesser amounts of diuretics was needed in pulsatile group during same postoperative period. Serum BUN/Cr level showed no specific difference and urine concentration power was well preserved in both groups. 5. Plasma proteins and other Enzymes showed no differences between two groups, but serum GOT/GPT level was higher in nonpulsatile group till POD 2. 6. Serum Electrolytes showed no differences between two groups. 7. WBC, RBC, Platelet counts, Hgb and Hct were not different and Coagulogram was well preserved in both groups. 8. Plasma free Hgb level was 7.09mg% in pulsatile group compared with 3.48mg% in pulsatile group on POD 1 but was normalized on POD 2. Gross hemoglobinuria after ECC was noted in 6 cases [20%] of pulsatile group and 4 cases [13%] of nonpulsatile group. 9. In both groups, most patients were included in NYHA class III to IV [28 cases;93% in nonpulsatile group, 22 cases;73% in pulsatile group] preoperatively, and well improved to class I to 11[22 cases; 73% in nonpulsatile group, 30 cases; 100% in pulsatile group] postoperatively. There were 7 operative mortalities in nonpulsatile group only, which were 5 cases of TOF with hepatic failure, 1 case of multiple VSDs with low out-put syndrome, and 1 case of mitral valvular heart disease with cardiomyopathy. We concluded that the new, commercially available Cobe-Stckert pulsatile roller pump device was safe, simple, and reliable.

• Journal of the Korean Chemical Society
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• v.62 no.1
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• pp.52-63
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• 2018

The purpose of this study was to observe and analyze how pre-service secondary chemistry teachers conduct open-ended, free style, exploratory chemistry experiments. The study examined common difficulties and tendencies that teachers showed in the chemistry labs. The study also investigated how these teachers deal with their difficulties and obstacles, such as unexpected results and device errors. Next, the study explored how students' epistemic goals and considerations have been shaped and changed as they interacted with one another and participated in their experiments over time. The study suggests that it could be more effective to gradually decrease guided-features of the experiment by providing appropriate scaffolding, than to start with completely open-ended inquiry labs. The study also suggests that the establishment of epistemic agency among group members influences the way they conduct experiments. Consequently, it is necessary to consider how instructional design for open-ended inquiry labs may provide students with scaffolds to encourage their active participation and to build responsibility in group discussions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.277-280
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• 2015

Smishing, Phishing personal privacy caused by Incident accidents such as Phishing information security has become a hot topic. Such incidents have privacy in personal information management occurs due to a lack of user awareness. This paper is based on the existing structure of the XML Tag question bank used a different Key-Value Structure-based JSON. JSON is an advantage that does not depend on the language in the text-based interchange format. The proposed system is divided into information security sector High, Middle and Low grade. and Provides service to the user through the free space and the smart device and the PC to the constraints of time. The use of open source Apache Load Balancing technology for reliable service. It also handles the user's web page without any training sessions Require server verification result of the training(training server). The result is sent to the training server using jQuery Ajax. and The resulting data are stored in the database based on the user ID. Also to be used as a training statistical indicators. In this paper, we design a level training system to enhance the user's information security awareness.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.11
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• pp.1271-1276
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• 2015

The recent trend is that diesel power generation on islands where its prime cost for power generation is high is replaced by new and renewable energy. Therefore, south Jeolla province is progressing the construction project of self-sufficient islands for the areas where power is supplied by depending on diesel generators, which is the project that power is supplied through eco-friendly energy source using sunlight, wind power and energy storage device etc. However, it is difficult to construct new and renewable energy source with the capacity to respond to the load perfectly due to its environmental and geographical conditions regarding capacity design of new and renewable energy. Besides, Microgrid design considering appropriate capacity design of the system components and efficient operation is required through the analysis of climate conditions and load patterns from the design stage for optimal composition of a hybrid system with economic feasibility. Therefore, this study is aimed to conduct a research on optimal combination, capacity calculation and economic feasibility by comprising a hybrid power generation system which will replace 40% of power generation by diesel as new and renewable energy source for Geomun Island where has more than 300 households and requires expansion of the facility among islands located in southwest coast.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.65-71
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• 2016

Although high mammographic density is one of the strongest predictors of breast cancer risk, X-ray based mammography cannot be performed before the recommended screening age, especially not in adolescents and young women. Therefore, new techniques for breast density measurement are of interest. In this pilot study in Guam and Hawaii, we evaluated a radiation-free, bioimpedance device called Electrical Breast Densitometer$^{TM}$ (EBD; senoSENSE Medical Systems, Inc., Ontario, Canada) for measuring breast density in 95 women aged 31-82 years and 41 girls aged 8-18 years. Percent density (PD) was estimated in the women's most recent mammogram using a computer-assisted method. Correlation coefficients and linear regression were applied for statistical analysis. In adult women, mean EBD and PD values of the left and right breasts were $230{\pm}52$ and $226{\pm}50{\Omega}$ and $23.7{\pm}15.1$ and $24.2{\pm}15.2%$, respectively. The EBD measurements were inversely correlated with PD ($r_{Spearman}=-0.52$, p<0.0001); the correlation was stronger in Caucasians ($r_{Spearman}=-0.70$, p<0.0001) than Asians ($r_{Spearman}=-0.54$, p<0.01) and Native Hawaiian/Chamorro/Pacific Islanders ($r_{Spearman}=-0.34$, p=0.06). Using 4 categories of PD (<10, 10-25, 26-50, 51-75%), the respective mean EBD values were $256{\pm}32$, $249{\pm}41$, $202{\pm}46$, and $178{\pm}43{\Omega}$ (p<0.0001). In girls, the mean EBD values in the left and right breast were $148{\pm}40$ and $155{\pm}54{\Omega}$; EBD values decreased from Tanner stages 1 to 4 ($204{\pm}14$, $154{\pm}79$, $136{\pm}43$, and $119{\pm}16{\Omega}$ for stages 1-4, respectively) but were higher at Tanner stage 5 ($165{\pm}30{\Omega}$). With further development, this bioimpedance method may allow for investigations of breast development among adolescent, as well as assessment of breast cancer risk early in life and in populations without access to mammography.

• The Journal of Art Theory & Practice
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• no.13
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• pp.7-33
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• 2012

The memory of the Korean War is about the time period when people lived toughly during evacuation, due to being exposed to the natural climate such as intense cold or heat without any protection, leaving their comfortable home and living in temporary built shelters which were barely enough to avoid the wind. 'Death is concealed and only the figures of evacuation for survival were expressed, just as how the government ordered. Since the experience of the battlefield is personal and fragmentary, that is broken into pieces, it does not have compatibility. As war is a distorted experience that cannot be placed in a big picture, it is not possible to take a view of the war's big picture. Having this individualized experience as a common collective memory is an issue and it is the will that people tries to pursue. The reason why the evacuees from north to south, and as well as from the south to further south were all able to be adopted as the theme of artworks due to the military action that emptied the occupied territories of the North Korean Army under the forced removal command. In such situations, the natural state of the 'snow' was like a symbol of the 1.4 Recession. The group of people who were thrown into the intense cold displaced the war damage of loosing their base livelihood, and symbolized the obedient citizens who faithfully follow their government's command. The figure of advocating anti-communism is projected as a figure of a refugee during cold winter-time and it contains ones past which he or she obeyed its own country's commands. Evacuation, especially the evacuation during the winter is a visual device that can confirm these kinds of country's command. The consequences were same for the artists as well. Therefore, the situation being communal could be found due to the individual experiences during war are ideological. The image of the refuge shown in the picture played the role of strengthening the consciousness of defecting to South Korea into the meaning of the 'Finding Freedom.' I would like to express that the reason of them leave their home during the harsh winter is in order to avoid the oppression of the Communist Party. The evacuation that people went through was not to 'Finding Freedom', but 'To Survive'. Later, this evacuation has been imprinted as a behavior of choosing free Republic of Korea, which was an ideological issue. Anti-communism was the rule of survival in South Korea society, and people have the tendency to remember what they want to remember. As it is not the people who possesses an incident, but the memory that possesses ones, people cover their memory with disguised plots in order to forget the violence and to live a different prologue. They share the incident of violence as a hurtful memory. The tragedy of the Korean War was the result of Ideology and being in between the powerful nations' rights, but the violence during the war has been depicted as a natural disaster, which was the evacuation in heavy snow.