• Land and Housing Review
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• v.7 no.4
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• pp.307-314
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• 2016

Energy harvesting technique is to utilize energy that is always present but wasted. In this study, we have developed the energy harvester of the hybrid method utilizing both vibration and pressure of the vehicle traveling a road or parking lot. In the previous study, we have developed a prototype energy harvester, improved hybrid energy harvester, and developed a final product that offers improved performance in the hybrid module. The results were published in the previous paper. In this study, we installed the finally developed hybrid module in the actual parking lot. And we measured the power generation performance due to pressure and vibration, and the running speed of the vehicle when the vehicle is traveling. And we compared the results with those obtained in laboratory conditions. In a previous study performed in laboratory conditions the maximum power of the energy block was 1.066W when one single time of vibration, and 1.830W when succession with 5 times. On the other hand, in this study, we obtained the average power output of 0.310W when the vehicle is running at an average 5 km/h, 0.670W when at an average 10 km/h, and 1.250W when at an average 20 km/h, and 2.160W when at an average 5 km/h. That is, the higher the running speed of the vehicle has increased power generation performance. However, when compared to laboratory conditions, the power generation performance of the energy block in driving speed by 20km/h was lower than those in laboratory conditions. In addition, when compared to one time of vibration of laboratory conditions, power generation performance was higher when the running speed 20km/h or more and when five consecutive times in laboratory conditions, it was higher when the running speed 30km/h or more. It could be caused by a difference of load conditions between the laboratory and the actual vehicle. Thus, applying the energy block on the road would be more effective than that on the parking lot.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.298-298
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• 2014

Quantum dot infrared photodetectors (QDIPs) based on Stranski-Krastanov (SK) quantum dots (QDs) have been widely explored for improved device performance using various designs of heterostructures. However, one of the biggest limitations of this approach is the "pancake" shape of the dot, with a base of 20-30 nm and a height of 4-6 nm. This limits the 3D confinement in the quantum dot and reduces the ratio of normal incidence absorption to the off-axis absorption. One of the alternative growth modes to the formation of SK QDs is a sub-monolayer (SML) deposition technique, which can achieve a much higher density, smaller size, better uniformity, and has no wetting layer as compared to the SK growth mode. Due to the advantages of SML-QDs, the SML-QDIP design has attractive features such as increased normal incidence absorption, strong in-plane quantum confinement, and narrow spectral wavelength detection as compared with SK-DWELL. In this study, we report on the improved device performance of InAs/InGaAs SML-QDIP with different composition of $Al_xGa1-_xAs$ barrier. Two SML-QDIPs (x=0.07 for sample A and x=0.20 for sample B) are grown with the 4 stacks 0.3 ML InAs. It is investigated that sample A with a confinement-enhanced (CE) $Al_{0.22}Ga_{0.78}As$ barrier had a single peak at $7.8{\mu}m$ at 77 K. However, sample B with an $Al_{0.20}Ga_{0.80}As$ barrier had three peaks at (${\sim}3.5{\mu}m$, ${\sim}5{\mu}m$, ${\sim}7{\mu}m$) due to various quantum confined transitions. The measured peak responsivities (see Fig) are ~0.45 A/W (sample A, at $7.8{\mu}m$, $V_b=-0.4V$ bias) and ~1.3 A/W (sample B, at $7{\mu}m$, $V_b=-1.5V$ bias). At 77 K, sample A and B had a detectivity of $1.2{\times}10^{11}cm.Hz^{1/2}/W$ ($V_b=-0.4V$ bias) and $5.4{\times}10^{11}cm.Hz^{1/2}/W$ ($V_b=-1.5V$ bias), respectively. It is obvious that the higher $D^*$ of sample B (than sample A) is mainly due to the low dark current and high responsivity.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.23-32
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• 2020

The compression sensing technology, CAFB, was developed to obtain the raw signal of the target structure by compressing it into a signal of the intended frequency range. At this point, for compression sensing, the CAFB can be optimized for various reference signals depending on the desired frequency range of the target structure. In addition, optimized CAFB should be able to efficiently compress the effective structural answers of the target structure even in sudden/dangerous conditions such as earthquakes. In this paper, the targeted frequency range for efficient structural integrity monitoring of relatively flexible structures was set below 10Hz, and the optimization method of CAFB for this purpose and the seismic response performance of CAFB in seismic conditions were evaluated experimentally. To this end, in this paper, CAFB was first optimized using Kobe seismic waveform, and embedded it in its own wireless IDAQ system. In addition, seismic response tests were conducted on two span bridges using Kobe seismic waveform. Finally, using an IDAQ system with built-in CAFB, the seismic response of the two-span bridge was wirelessly obtained, and the compression signal obtained was cross-referenced with the raw signal. From the results of the experiment, the compression signal showed excellent response performance and data compression effects in relation to the raw signal, and CAFB was able to effectively compress and sensitize the effective structural response of the structure even in seismic situations. Finally, in this paper, the optimization method of CAFB was presented to suit the intended frequency range (less than 10Hz), and CAFB proved to be an economical and efficient data compression sensing technology for instrumentation-monitoring of seismic conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.357-367
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• 2018

Recent earthquakes in Gyeongju and Pohang have raised interest in liquefaction in South Korea. Liquefaction, which is a phenomenon that excessive pore pressure is generated and the shear strength of soil is decreased by repeated loads such as earthquakes, causes severe problems such as ground subsidence and overturning of structures. Therefore, it is necessary to identify and prepare for the possibility of liquefaction in advance. In general, the possibility of liquefaction is quantitatively assessed using the Liquefaction Potential Index (LPI), but it takes a lot of time and effort for performing site response analysis which is essential for the liquefaction evaluation. In this study, a simple method to evaluate the liquefaction potential without executing the site response analysis in a downtown area with a lot of borehole data was proposed. In this simple method, the correlation between the average shear wave velocity of the target location ground and the LPI divided by thickness of liquefiable layer was established. And the applicable correlation equation for various rock outcrop accelerations were derived. Using the 104 boreholes information in Seoul, the correlation equation between LPI and the shear wave velocity (ground water level: 0m, 1m, 2m, 3m) is obtained and the possibility of liquefaction occurrence in Seoul and Gyeongju is evaluated. The applicability of the proposed simple method was verified by comparing the LPI values calculated from the correlation equation and the LPI values derived using the existing site response analysis. Finally, the distribution map of LPI calculated from the correlation was drawn using Kriging, a geostatistical technique.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.4
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• pp.206-216
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• 2017

The temporal distribution of the turbulence kinetic energy (TKE) and the vertical component of Reynolds stresses ($-{\bar{u^{\prime}w^{\prime}}}$) was measured during one wave period under high wave energy conditions. The wave data were obtained at Hujeong Beach in the east coast of Korea at January 14~18 of 2017 when an extratropical cyclone was developed in the East Sea. Among the whole thousands of waves measured during the period, hundreds of regular waves that had with similar pattern were selected for the analysis in order to give three representing mean wave patterns using the ensemble average technique. The turbulence properties were then estimated based on the selected wave data. It is interesting to find out that $-{\bar{u^{\prime}w^{\prime}}}$ has one clear peak near the time of flow reversal while TKE has two peaks at the corresponding times of maximum cross-shore velocity magnitudes. The distinguished pattern of Reynolds stress indicates that vertical fluxes of such properties as suspended sediments may be enhanced at the time when the horizontal flow direction is reversed to disturb the flows, supporting the turbulence convection process proposed by Nielsen (1992). The characteristic patterns of turbulence properties are examined using the CADMAS-SURF Reynolds-Averaged Navier-Stokes (RANS) model. Although the model can reasonably simulate the distribution of TKE pattern, it fails to produce the $-{\bar{u^{\prime}w^{\prime}}}$ peak at the time of flow reversal, which indicates that the application of RANS model is limited in the prediction of some turbulence properties such as Reynolds stresses.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.137-148
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• 2010

The Myoungbong mine located in Boseong-gun, Jellanamdo consists of Au-Ag bearing quartz veins which filled the fissures of Bulguksa granitic rocks of Cretaceous. The tailings obtained from the Myungbong mine were used to investigate the effects of various processes, such as oxidation of primary sulfides and formation(alteration) of secondary and/or tertiary minerals, on arsenic immobilization in tailings. This study was conducted via both mineralogical and chemical methods. Mineralogical methods used included gravity and magnetic separation, ultrasonic cleaning, and instrumental analyses(X-ray diffractometry, energy-dispersive spectroscopy, and electron probe microanalyzer) and aqua regia extraction technique for soils was applied to determine the elemental concentrations in the tailings. Iron (oxy)hydroxides formed as a result of oxidation of tailings were identified as three specific forms. The first form filled in rims and fissures of primary pyrites. The second one precipitated and coated the surfaces of gangue minerals and the final form was altered into yukonites. Initially, large amounts of acid-generating minerals, such as pyrite and arsenopyrite, might make the rapid progress of oxidation reactions, and lots of secondary minerals including iron (oxy)hydroxides and scorodite were formed. The rate of pH decrease in tailings diminished, in addition, as the exposure time of tailings to oxidation environments was prolonged and the acid-generating minerals were depleted. Rather, it is speculated that the pH of tailings increased, as the contribution of pH neutralization reactions by calcite contained in surrounding parental rocks became larger. The stability of secondary minerals, such as scorodite, were deteriorated due to the increase in pH, and finally arsenic might be leached out. Subsequently, calcimn and arsenic ions dissociated from calcites and scorodites were locally concentrated, and yukonite could be grown tertiarily. It is confirmed that this tertiary yukonite which is one of arsenate minerals and contains arsenic in high level plays a crucial role in immobilizing arsenic in tailings. In addition to immobilization of arsenic in yukonites, the results indicate that a huge amount of iron (oxy)hydroxides formed by weathering of pyrite which is one of typical primary minerals in tailings can strongly control arsenic behavior as well. Consequently, this study elucidates that through a sequence of various processes, arsenic which was leached out as a result of weathering of primary minerals, such as arsenopyrite, and/or redissolved from secondary minerals, such as scorodite, might be immobilized by various sorption reactions including adsorption, coprecipiation, and absorption.

• Cartoon and Animation Studies
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• s.48
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• pp.359-383
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• 2017

3,000 years ago, since the first poster of humanity appeared in Egypt, the invention of printing technique and the development of civilization have accelerated the poster production technology. In keeping with this, the expression of poster has also been developed as an attempt to express artistic sensibility in a simple arrangement of characters, and now it has become an art form that has become a domain of professional designers. However, the technological development in the expression of poster is keep staying in two-dimensional, and is dependent on printing only that it is irrelevant to the change of ICT environment based on modern multimedia. Especially, among the many kinds of posters, the style of movie posters, which are the only objects for video, are still printed on paper, and many attempts have been made so far, but the movie industry still does not consider ICT integration at all. This study started with the feature that the object of the movie poster dealt with the video and attempted to introduce the augmented reality to apply the dynamic image of the movie to the static poster. In the graduation work of the media design major of a university in Korea, the poster of each works for promoting the visual work of the students was designed and printed in the form of a commercial film poster. Among them, 6 artworks that are considered to be suitable for augmented reality were selected and augmented reality was introduced and exhibited. Content that appears matched to the poster through the mobile device is reproduced on a poster of a scene of the video, but the text informations of the original poster are kept as they are, so that is able to build a moving poster looked like a wanted from the movie "Harry Potter". In order to produce this augmented reality poster, we applied augmented reality to posters of existing commercial films produced in two different formats, and found a way to increase the characteristics of AR contents. Through this, we were able to understand poster design suitable for AR representation, and technical expression for stable operation of augmented reality can be summarized in the matching process of augmented reality contents production.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.660-664
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• 2004

Background: Dilution of blood cardioplegia is not needed in IAWBC as it is in cold blood cardioplegia because it does not aggregate red blood cells on normal body temperature and does not compromise micro coronary circulation. This study was designed to evaluate the safety and efficacy of undiluted potassium solution in IAWBC. Material and Method: Thirty patients who underwent CABG with IAWBC were grouped into dilutedplegia (n=14) and microplegia (n=16). Potassium was delivered conventionally with 4 : 1 delivery kit in the dilutedplegia group. The undiluted potassium was directly connected on the blood of oxygenator in the microplegia group. Result: There were no differences in sex, age, left ventricular ejection fraction, number of grafts, aortic cross clamping time, and the value of perioperative myocardial enzyme between the two groups. There were no perioperative myocardial infarction and hospital mortality. The amount of crystalloid cardioplegia was 1346$\pm$597 mL in dilutedplegia (mean$\pm$standard deviation, and 28$\pm$9 mL in microplegia (p<0.0001). The hematocrit during cardiopulmonary bypass was 21$\pm$4% in dilutedplegia and 24$\pm$3% in microplegia (p>0.05). 11 patients in dilultedplegia received blood transfusion, but 4 patients in microplegia received blood transfusion (p<0.05). The amount of urine and hemofiltration during the operation were more in dilutedplegia (1250$\pm$810 mL, 1689$\pm$548 mL) than in microplegia (959$\pm$410 mL, 1461$\pm$784 mL; p<0.05). Conclusion: The undiluted potassium of IAWBC in CABG operation is a safe, effective technique for myocardial protection to prevent fluid overload, and blood transfusion. There is no need to use the delivery kit.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.1
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• pp.159-165
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• 2018

In recent years, universal design concepts have been introduced that are designed to make everybody more comfortable and safe to use for products, buildings, environments, services, and so on. In the case of urban railroad history, it is important to maintain facilities that incorporate the universal design concept because it is an important facility that serves as a base of city life and there are various users. This research is the last annual task of 5 years as part of the project of "Development of Technique to Improve the Convenience of Urban Railway History User" by the National Institute of Transportation Technology Promotion Agency. The purpose of this study is to develop criteria and method of facilities convenience evaluation based on UD and to evaluate user convenience by selecting test bed station. For this purpose, the UD principle of the historic facilities of Weihai Urban Railway was established and detailed evaluation criteria were presented. As a result of evaluating the test bed history using the 5-point Likert scale of the joint research institute / railway operating agency / expert, 50.3% of convenience improvement was achieved. As a result of evaluating the applicability according to the UD principle, 48.7% Respectively. The evaluation criteria and methodology based on the UD suggested in this study is a quantitative method for evaluating UD application of urban railway facilities in the future.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.119-127
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• 2015

To date, detection of microbial populations in dairy products has been performed using culture media, which is a time-consuming and laborious method. The recently developed chromogenic media could be more rapid and specific than classical culture media. However, the newly developed molecular-based technology can detect microbial populations with greater rapidity and sensitivity than the classical method involving culture media and chromogenic media. This molecular-based technology could provide various options for monitoring the characterization of different states of bacteria and cells. Thus, it could help upgrade the processing system of the dairy industry so as to maintain the safety and quality of dairy foods. Among the various newly developed molecular-based technologies, flow cytometry can potentially be used for monitoring microbiological populations in the dairy industry if official international standards are available for this purpose. When omics technology would have biomarker identification, it could be regarded as the rapid and sensitive analytical methods. Methods based on PCR, which has become a basic technique in microbiological research, can be developed and validated as alternative methods for quantification of dairy microorganisms. This review discusses methods for monitoring microbiological populations in dairy foods and the limitations of these studies, as well as the need for further research on such methods in the dairy industry.