• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.631-640
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• 2018

The application of an oxy-combustion circulating fluidized bed combustor (Oxy-CFBC) for low grade coals has recently developed in the world to meet the continuous increase of energy demand and to achieve the reduction of greenhouse gases. Since demo plants for Oxy-CFBC have been developed, the combustion properties of Oxy-CFBC in various operation conditions, such as gas flow rates, combustion temperature, fuel, and so on, should be investigated to develop design criteria for a commercial Oxy-CFBC. In this study, a computational simulation tool for Oxy-CFBC was developed on the basis of the IEA-CFBC (International Energy Agency Circulating Fluidized Bed Combustor) model. Simulation was performed under various conditions such as reaction temperature ($800^{\circ}C{\sim}900^{\circ}C$), oxygen contents (21%~41%), coal feeding rate, Ca/S mole ratio (1.5~4.0), and so on. Simulation results show that the combustion furnace temperature is higher in oxy 1 than air fired. However, the temperature gradient tended to decrease with increasing oxy mixing percent. In case of $SO_x$, the higher the Ca/S mole ratio and oxy mixing percent, the higher the desulfurization efficiency.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.762-767
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• 2016

High thermal efficiency and the ability to use various types of fuel are a few of the many advantages of diesel engines. However, a major disadvantage is that their exhaust emissions are more harmful to humans and the environment than that of conventional engine. Consequently, the provisions of the international emissions standards for diesel engine equipped passenger cars, commercial vehicles, and ships have become more stringent. These standards include the EU Euro 6, the IMO MEPC Tier 3, and the US EPA Tier 4. Ryu et al. published a study that applied fuel additives to two-stroke diesel engines. In this study, a four-stroke diesel engine using diesel oil for a generator is utilized as the test subject, and an experiment is performed to verify whether fuel additive can be used to improve performance and exhaust emissions. In addition, this experimental study presents research results for the application of fuel additives in both two-stroke and four-stroke diesel engines. The experimental results were compared and analyzed by placing an oil-soluble calcium-based organometallic compound in diesel oil. The results confirmed that the addition of fuel additive improved the performance (fuel consumption rate, exhaust gas temperature) and exhaust emissions (NOx, CO) of the diesel engine.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.1
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• pp.51-58
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• 2013

As it is changing into aging society, rehabilitation, welfare and sports industry markets are being expanded fast. Especially, the field of vital signals interface to control welfare instruments like wheelchair, rehabilitation ones like an artificial arm and leg and general electronic ones is a new technology field in the future. Also, this technology can help not only the handicapped, the old and the weak and the rehabilitation patients but also the general public in various application field. The commercial bio-signal measurement instruments and interface systems are complicated, expensive and large-scaled. So, there are a lot of limitations for using in real life with ease. this thesis proposes a wireless transmission interface system that uses EMG(electromyogram) signals and a control module to manipulate hardware systems with portable size. We have designed a hardware module that receives the EMG signals occurring at the time of wrist movement and eliminated noises with filter and amplified the signals effectively. DSP(Digital Signal Processor) chip of TMS320F2808 which was supplied from TI company was used for converting into digital signals from measured EMG signals and digital filtering. We also have used PCA(Principal Component Analysis) technique and classified into four motions which have right, left, up and down direction. This data was transmitted by wireless module in order to display at PC monitor. As a result, the developed system obtains recognition success ratio above 85% for four different motions. If the recognition ratio will be increased with more experiments. this implemented system using EMG wrist direction signals could be used to control various hardware systems.

• Journal of Acupuncture Research
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• v.27 no.1
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• pp.75-86
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• 2010

Objectives : We developed and proposed a guideline for safety and performance assessment of electric moxibustion apparatus (class II medical device). Methods : We drafted the guideline for safety and performance assessment of electric moxibustion apparatus by referring the existing standards, guidelines and measurement data from commercially available products. Temperature characteristics such as maximum temperature and ramp time, and physical characteristics such as weight, noise and diameter were measured. User friendliness was also evaluated for commercial devices. Results : This guideline only can be applied to the electric moxibustion apparatus where moxa is being heated by electricity for medical proposes. Maximum temperature of higher than $50^{\circ}C$ can be achieved mostly. Ramp rate of temperature seems to be reliable. Control of temperature is needed to be improved. Moxa and its derivative products seem to be regulated for reliable temperature performance for clinical application. Requirements for design and development of electric moxibustion apparatus are suggested : temperature indicator, temperature control and its accuracy, safety measure, surge protection, user friendliness and instruction for use (IFU). Design recommendation of the reduction of noise level and energy loss are suggested for better products. Conclusions : We proposed a guideline for safety and performance assessment of electric moxibustion apparatus to improve the quality of relating products and aid their commercialization by aiming higher industrial competitiveness of the medical device sectors in Korea. Discussion with related institutes such as industry, academy and government is further required. Public hearings also need to be held prior to the establishment of a final guideline and standard.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.577-583
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• 2016

Small-sized persimmons produced by high crop load are better accepted in the export markets. However, maintaining high crop load frequently results in weakness of tree vigor, deterioration of fruit quality, and increase of the risks for alternate bearing. This experiment was conducted to determine the combined effects of fertilization rate and leaf-fruit (L/F) ratio on container-grown 3-year-old 'Fuyu' persimmon trees. Application of 3.6-g N, 2.1-g $P_2O_5$, 2.7-g $K_2O$, 2.7-g CaO, and 0.6-g MgO was for the control fertilization rate (CF) and that of a 3-fold CF was for the high fertilization rate (HF). Commercial fertilizers were surface-applied to a container on July 6, July 17, and August 10 in three equal aliquots. Single tree for each fertilization rate was assigned for 12 L/F ratios (5, 6.3, 7.7, 9, 10.4, 13, 15.5, 18, 21, 24, 27, and 33) mostly by fruit thinning or rarely by defoliation on July 1. HF did not affect the yield, weight and soluble solids of the fruits but decreased skin color. As L/F ratio increased, yield decreased but average weight, skin color, and soluble solids of fruits increased. With HF, N and K concentrations in leaves, fruits, and shoots increased to some extent but soluble sugars in dormant shoots decreased. Many shoots were cold-injured with low L/F ratio especially at the HF. HF did not increase number of flower buds the next spring either on a shoot or on a tree basis but increased shoot length, compared with the CF. Increasing L/F ratio markedly increased number of flower buds and shoot growth the following year at both fertilization rates. Therefore, an appropriate combination of fertilization rate and L/F ratio should be necessary to maintain stable fruit production and tree vigor at high crop load.

• Clean Technology
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• v.24 no.1
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• pp.27-34
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• 2018

Catalytic filter has many advantages for the industrial application owing to its bi-functional ability to treat nitrogen oxides and particulate simultaneously. The technical feasibility of using the catalytic filter in the flue gas treatment process will be more promoted if the high porous ceramic sheet filter is utilized. However, it is not easy to prepare the effective catalytic filter using sheet filter as it has less room for catalyst support due to its thin layer. In this study, catalytic filter using a domestic ceramic sheet filter element has been prepared and conducted the experimental evaluation for NO reduction performance. The current sheet filter element shows the low catalytic activity less than 92% conversion for NO concentration 700 ppm at the face velocity $0.02m\;s^{-1}$. This unexpected low catalytic activity seems to be caused by the present of extraordinary large pores from the lack of uniformity in the pore size distribution of the sheet filter. The large pore size of the sheet filter is reduced by composing the smaller powder as its raw material, which presents improvement in NO conversion more than 96%. More improvement is observed showing 98% NO conversion which is applicable to a commercial plant when the catalyst coating layer is expanded by adding the large $TiO_2$ particles during the catalyst preparation. Both of above two methods is regarded as that the broad gates of the larger pores in the coating layer are effectively filled with the proper catalyst. So these results encourage the utilization of sheet filter as a good catalytic filter material with its potential merit of high permeability.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.1
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• pp.55-61
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• 2010

This investigation has been carried out for the purpose of the examination of current Gwangju and Jeonnam clinical pathology students' recognition of their departments and of effective employment guidance. Furthermore, it has examined the students' recognition on two sides; namely, their satisfaction with their own departments and their recognition of the employment of medical technologists. This investigation, with 389 students as its subjects from the clinical pathology departments at 4 universities in the Gwangju-Jeonnam Region, has compared and analyzed the data from the survey with a questionnaire from November 2008 to June 2009 by using the SPSS 12.0 package. Some of the remarkable results from the yielded data are as follows. As for the motivation for their application to the clinical pathology departments, the investigation of the students' satisfaction with their departments has revealed that 47.5% of the subjects indicated recommendation from friends or acquaintances while 22.1% reported that they had been informed of the departments through Internet. 70.4% of the subjects graduated from general high schools, 22.3% from commercial high schools, and 6.2% from technical high schools. Applicants from general high schools tend to decrease in number every year. 28.5% of the students judged professor's capability of lecture as an important part of their acquisition of licenses, and more than 65.6% of the subjects acknowledged the necessity of their self-study at night for the acquisition of license. As for the future prospect of the occupation of clinical technologist, 46.8% of the students replied that it was promising, while 39.1% reported that they had no ideas. From this we can confirm that the students of clinical pathology lacked a viewpoint of occupation and goals for future jobs. The investigation of the students'recognition of the employment of clinical technologists has revealed that 47.8% of them wanted to be employed in the Seoul-Gyeonggi Region due to the properties of their local universities, 29.0% of themlogpecteties of monesly salary to be 1,200,000~1,300,000 won, while 22.4% 1,300,000~1,400,000 won. These fiemres indicated that these students' salary ogpectations were relativplo lower than those from cities ertiprovinces. As for the greatest difficulty after employment, 31.1% of the subjects indicated the confliction among employees from variouatiolleges, 27.3% uncertainty of duties related to es of major, 24.9% bmrdens of self-development.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.128-138
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• 2014

Development of infrastructure component libraries is a critical requirement for the accelerated adoption of BIM in the civil engineering sector. Libraries reduce the time for BIM model creation, allows accurate quantity take offs, and shared use of standard models in a project. However, such libraries are currently in very short supply in the domestic infrastructure domain. This research introduces library components for retaining walls and box culverts generated from 2D standard drawings made publicly available by MOLIT. Commercial BIM software was used to create the concrete geometry and rebar, and dimensional/volumetric parameters were defined to maximize the reuse and generality of the libraries. Use of the these libraries in a project context demonstrates that they allow accurate and quick quantity take offs, and easier management of geometric information through the use of a single library as to numerous 2D drawings. It also demonstrates the easy modification of the geometries of the components if and when they need to changed. However, the application also showed that some of the rebar components (stirrups and length wise rebars) do not get properly updated when concrete geometries are changed, demonstrating the limits of current software applications. The research provides evidence of the many advantages of using BIM libraries in the civil engineering, thus providing the incentive for further development of standard libraries and promoting the use of BIM in infrastructure projects.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.452-458
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• 2012

Rare earth elements fertilizer and Ca were sprayed on eight-year-old 'Fuji'/M.9 apple trees during two consecutive seasons, and fruit quality was quantified at harvest and 5-month long storing in a commercial cooling house at $4^{\circ}C$ and 80~85% RH. In the first season, single-sprayed of rare earth elements fertilizer showed appreciable accumulations of its elements (La, Pr, Gd, and Nd) in the fruit. In the following season, application of higher doses accumulated higher amount, indicating that the accumulation of rare earth elements was dose-dependent. However, rare earth elements did not affect the accumulations of Ca, Mg, and K in 'Fuji' apple fruit showed that there was no interaction between rare earth elements and these macronutrients. Double-spray of 0.2% rare earth elements increased fruit redness at harvest and had exhibited better color. Although at harvest it did not show significant effects on fruit weight, pulp firmness and titratable acidity (TA), but had pronounced effects on inhibiting fruit softness and retarded decrease of TA during storing. Furthermore, it reduced respiration rate and inhibited ethylene production during storing indicated that rare earth elements may be an alternative for prolonging the shelf life of 'Fuji'/M.9 apple fruit.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.27-31
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• 2009

Top spray-drying method is frequently utilized for flavor encapsulation, but the top spray-dried products frequently suffer from high losses of volatile flavor as the result of a high processing temperature (150-$300^{\circ}C$). In an effort to solve these problems, a low-temperature fluidized-bed granulating method was utilized to encapsulate the flavor. For the encapsulation of sesame oil, oil-in-water emulsions of sesame oil and a mixture of maltodextrin, modified starch, gum arabic, and gellan gum were bottom-sprayed at milder temperatures (70-$100^{\circ}C$) using a fluidized-bed granulator. Sesame oil extracts from microcapsules were obtained via a simultaneous distillation/extraction technique, and the retention of volatile flavor compounds was analyzed via a gas chromatography-mass spectrometry. The retention of volatile flavors of sesame oil per se, spray-dried and fluidized-bed granulated microcapsules after 3-day-storage at $37^{\circ}C$ were 0.8%, 37.2%, and 42.0%, respectively. In addition, the low-temperature fluidized-bed granulation showed higher encapsulation yield and sensory preferences for the application of commercial products (beef rice porridge), as compared to spray drying.