• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.2
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• pp.114-119
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• 2013

The present study tested 5 concrete mixes to develop reliable mixing proportions for the sustainable alkali-activated(AA) foamed concrete as a thermal insulation material for the floor heating system of buildings. The AA binder used was composed of 73.5% ground granulated blast-furnace slag, 15% fly ash, 5% calcium hydroxide, and 6.5% sodium silicate. As a main variable, the unit binder content varied from $325kg/m^3$ to $425kg/m^3$ at a space of $25kg/m^3$. The test results revealed that AA foamed concrete has considerable potential for practical applications when the unit binder content is close to $375kg/m^3$, which achieves the minimum quality requirements specified in KS F 4039 and ensures economic efficiency. In addition, lifecycle assessment demonstrated the reduction in the environmental impact profiles of all specimens relative to typical ordinary portland cement foamed concrete as follows: 99% for photochemical oxidation potential, 87~89% for global warming potential, 78~82% for abiotic depletion, and 70~75% for both acidification potential and human toxicity.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.143-155
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• 2016

Recently, the interest on applying AVM(Around View Monitoring) systems in construction equipments have been increasing due to the demand for better control, work efficiency and safety. Most of the existing AVM systems have been developed focusing on the application in automobiles and only several AVM systems have been developed for construction equipments. However, the original technology of AVM remained the same as in the automobiles that failed to consider the main properties of construction equipments and suggest appropriate range of AVM display (Top-view). Therefore, the purpose of this study is to suggest a pilot type of AVM system for construction equipment. Accordingly, literature review, deduction of main consideration factors, selection of sensors, system design, algorithm development of a pilot type of AVM system for construction equipment have been conducted. A laboratory experiment has also been conducted for the deduction of further improvements. As a result, a minimum image refresh rate of 20 fps has been achieved that clearly reflects the actual situation of the equipment and also, the actual motions of Boom, Arm, Bucket have been displayed appropriately on the AVM system based on the angle data collected by sensors. However, the experiment results have also shown that the following tasks still remain for future work: 1)Improvement of AVM image interpolation, 2)Development of calibration module for variety construction equipment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1623-1630
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• 2011

The effects of addition of citrus peel powders (C 0, 0.5, 1 & 2%), dried Lentinus edodes powders (L 0, 0.5, 1 & 2%), and their combination (C-L) on the chemical, sensory and textural properties of pork sausages were studied. Addition of 0.5, 1 or 2% C, L, and C-L all significantly decreased moisture content, pH, and color a-values of sausage samples, whereas ash content and color b-value were increased (p<0.05). C, L, and C-L did not affect protein, fat, carbohydrates contents or texture characteristics. Sensory evaluation was performed by multivariate data analysis, namely principal component analysis (PCA). Eighty-two percent total variation was observed in the main structured information among the test groups: the first (PC1) and second (PC2) components of variation were 59 and 23%, respectively. Eight parameters (sweet flavor, pork aroma, bitterness, rancidity, salty flavor, color, sour flavor and citrus aroma) were utilized to describe the main sensory characteristic of the sausages. Addition of 0.5, 1 & 2% citrus peel was obviously correlated with PC1 (salty flavor, sour flavor and citrus aroma, pork aroma, and sweet flavor and rancidity), whereas addition of 0.5 & 1% Lentinus edodes was related with PC2 (aroma and rancidity).

• Journal of Internet Computing and Services
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• v.1 no.2
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• pp.29-37
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• 2000

Asynchronous transfer mode is flexible to support multimedia communication services using asynchronous time-sharing and statistical multimedia techniques to the existing data communication area, ATM ABR service controls network traffic using feedback information on the network congestion situation in order to guarantee the demanded service qualities and the available cell rates, In this paper we apply the control method using queue length prediction to the formation of feedback information for more efficient ABR traffic control. If backward node receive the longer delayed feedback information on the impending congestion, the switch can be already congested from the uncontrolled arriving traffic and the fluctuation of queue length can be inefficiently high in the continuing time intervals, The feedback control method proposed in this paper predicts the queue length in the switch using the slope of queue length prediction function and queue length changes in time-series, The predicted congestion information is backward to the node, NLMS and neural network are used as the predictive control functions, and they are compared from performance on the queue length prediction. Simulation results show the efficiency of the proposed method compared to the feedback control method without the prediction, Therefore, we conclude that the efficient congestion and stability of the queue length controls are possible using the prediction scheme that can resolve the problems caused from the longer delays of the feedback information.

• The Transactions of the Korea Information Processing Society
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• v.4 no.1
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• pp.215-223
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• 1997

The advantages of service in satellite links are representatively a long distance and large capacity transfer and simultaneous communication. And terrestrial links are of high speed and high quality data transfer Therefore a combined form of characteristics of satellite and terrestrial links is desirable to furnish a good quality service to subscribers. And in satellite links an analysis method and a simulation method of file transfer are conducted to evaluate the efficiency of file transfer. The parameters are used the message length and transmission time, and the number of chain record and transmission time. From the results of evaluation, in satellite links, it is found that when the message length is shorter than 512 bytes, the file transmission time becomes extremely long and when the message length is set at 1024 bytes, the file transmission time abruptly increase from 2048 bytes. Also it is confirmed that when the number of chain record is under 15, the file transmission time becomes extremely long and if the number increase up to 90,the time becomes gradually short and over 90,it becomes constant.Therefore,from the result of file transmission in th case of utilizing satelite links,it is confirmed that the optimum message length in the minmum transmission time is present closely at 1024 bytes.Also it is confirmed that when the satelite transmission sped becoms smaller from 24kbps to2400bps,the optimum message length also becomes smaller from 640 bytes to 256bytes.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.519-525
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• 2016

This paper reports on analyzing the free and restrained shrinkage characteristic of ternary grout used cementitious admixture. In this study, the cementitious admixture was used such as fly ash, ziricania silica fume by combination of expansive additive (a, b) and shrinkage reducing agent. And a number of basic performance tests were conducted to investigate bleeding, volume change, fluidity and compressive strength behavior. According to the results, within appropriate mixing ratio, even the fluidity is not influenced by expansive additive and shrinkage reducing agent, the resistant properties of bleeding, volume change, shrinkage and compressive strength are increased. Comparing with plain grout, the free shrinkage reduced by a minimum of 29% which specimens are added expansive additive and shrinkage reducing agent. The combination of expansive additive a and shrinkage reducing agent is the most effective for reduction of shrinkage. And increasing the mixing ratio of expansive additive and shrinkage reducing agent extended cracking time. Nevertheless, combined addition of expansive additive a 2.0% and shrinkage reducing agent 0.50% has best shrinkage reduction behavior and not appeared cracking. From the above, the mixing ratio of 2.0% of expansive additive a and 0.50% of shrinkage reducing agent is high performance ternary grout for PSC bridge.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.577-582
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• 2016

This Study focused on the development of SMPS (Switching Mode Power Supply) to supply the constant votage and current nevertheless LED fluorescent Light generated the electric noise (with Harmonics) and Inrush current at instant time of turn-on and off. Recently, according to the Green policy in government, the LED fluorescent Lighter showed the rapidly increasing tend as indoor and outdoor Lighter. But, because of costs, LED fluorescent Light not considered and neglected the following items; power factor, efficiency, Harmonics and Inrush current. So, we are developed the SMPS about 3 key issues as follows: 1st, power factor and efficiency is 85%. 2nd, the switching noisy by harmonic is minimized. 3rd, the Inrush current at turn on and off time is reduced the minimum 0.3 A after $100{\mu}sec$ on turnon time. The proposed SMPS adjusted by LNK 409 driver (included the high frequency modulation function). Although, the developed SMPS maintained the about 85% of power factor and efficiency. but, the SMPS must be generated low heat by the variation of minute load current at switching timing. To improve the above weak point, the developed SMPS have the feedback monitoring circuit between input side and output side to maintain the power factor and efficiency. Also, we are studied the time-constant of control circuit to output the constant voltage and current nevertheless the load disturbance of LED lighting. The LED fluorescent Light of 46W is checked the above items.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.17 no.1
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• pp.13-17
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• 2011

There is a need in food industry to store minimally processed garlic for long time to have it be used just at the time of demand for final product processing. Optimal modified atmosphere packaging is expected to slow down the quality change extending its storage life. In order to find optimal packaging conditions, plastic films of different gas permeability properties (low density polyethylene (LDPE) $30{\mu}m$, polyolefin $50{\mu}m$ (PD 900), polyolefin $20{\mu}m$ (PD 941)) were used for packaging 400 g of minimally processed garlic. Perforated LDPE packages were prepared as control. The packaged products were stored at $1{\pm}1^{\circ}C$ for 52 days. Package treatments were compared in weight loss, decay, surface color, hardness and soluble solid content. While control package had normal atmosphere of air, LDPE, PD 900 and PD 941 packages attained internal concentration of $O_2$ 4.6% / $CO_2$ 12%, $O_2$ 0.9% / $CO_2$ 21% and $O_2$ 0.5% / $CO_2$ 13% after 45 days, respectively. Control packaging had rapid weight loss with high mold decay and great surface color change in 45 days. In PD 900 film packages of lowest gas permeability, the fresh-cut garlic could be stored without mold decay for 52 days. Except control packaging, there were no significant differences in surface color, hardness and soluble solid content among package treatments.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.44-49
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• 2007

The quality characteristics of strawberry jam containing different levels of sugar alcohols, such as xylitol, sorbitol and maltitol were compared with jam containing 35% of sugar only. Addition of 10-30% of xylitol did not influence pH and total acidity. The intensity of redness and amount of residual anthocyanin were increased according to increase of levels of xylitol, which showed a positive effect on color. However, the addition of more than 10% of xylitol resulted in negative changes in hardness and spreadmeter values. These and consumer preference results showed that the optimum amount of xylitol was less than 10%. Substituting sugar with 10% of xylitol and 25% of sorbitol, 10% of xylitol and 25% of maltitol or 10% of xylitol and 12.5% of sorbitol and maltitol did not change the pH, total acidity, hardness or spreadmeter value, but the redness and the amount of residual anthocyanin were still increased by these ratios. The most preferred ratio according to the sensory test was 10% of xylitol with 12.5% of sorbitol and maltitol each.

• Journal of Conservation Science
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• v.23
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• pp.103-118
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• 2008

Hobun(Oyster shell W.) is a traditional material used as extender and white pigment from ancient times. The production method of it, however, has been discontinued. We have studied the traditional production method of Hobun through calcination of oyster shell, which is one of the traditional ways for preparing Hobun. Our work has the important meaning in that we can reproduce the manufacturing method of the discontinued traditional material and also it provides a solid background knowledge to stabilize the production and supply of Hobun for the cultural asset repairing materials. The result can be summarized as followings: The production processes of Hobun by calcination method are divided into 4 steps - calcination ${\rightarrow}$ slaking(pulverization) ${\rightarrow}$ separating fine powder by submergence in water ${\rightarrow}$ drying. In calcination step, the temperature is required to exceed $700^{\circ}$ to get pure white color of Hobun, since organic materials in the shell cause the final powder to be less white below $600^{\circ}$. And the calcination methods produce significant amount of calcium hydroxide, which is incongruent for pigment materials without additional treatments. The experimental study also demonstrated that the additional treatment process introduced in traditional paintings can be a probable process since the calcium of potassium hydroxide is observed to be promoted by this treatment. It is also concluded that, the calcination method of Hobun is appropriate for a small amount and high quality production.