• Convergence Security Journal
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• v.13 no.2
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• pp.33-43
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• 2013

The Private Security Industry of Korea began after served security service for the United States army of 8 division. The industry grew up after establish private security regulation on December 31th of 1976. Early 1980's the industry was accelerated from bringing technical knowledge of developed nations rapidly. Also, private security was gotten into the spotlight by one of futurity industry instead public security after companies performed 86 Asian game and 88 Seoul Olympic successfully. Therefore, the industry became to increase qualitatively and quantitatively. From late 1990's the private security regulations were revised fifteen times and created about education system, bodyguard, and leader of security. 3,836 private companies and 150,030 private guards had operated until 2012. However, some of companies received administrative measure, because of the companies ran immorally. The minor companies are continuously closed down from the leader's inefficient operation. Approval standard of establishment has imperfect law. Solutions of problems are to provide high quality service, to expand company affairs, to attract specific customers through efficiency expert, to change standard of leader of security guards, to establish security education institution through the government and to intensify requirements to establish the company.

• KSBB Journal
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• v.24 no.3
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• pp.267-272
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• 2009

During a dilute acid hydrolysis, degradation products are formed or liberated by pre-treatment of lignocelluloses depend on both the biomass and the pretreatment conditions such as temperature, time, pressure, pH, redox conditions, and addition of catalysts. In lignocellulosic biomass, sugars can be degraded to furfural which is formed from pentoses and 5-hydroxymethulfurfural (HMF) from hexoses. 5-HMF can be further degraded, forming levulinic acid and formic acid. Acetate is liberated from hemicellulose during hydrolysis. Some decomposed compounds hinder the subsequent bioconversion of the solubilized sugars into desired products, reducing conversion yields and rates during fermentation. In the present work, samples of rapeseed strawwere hydrolyzed to study the optimal pretreatment condition by assessing yields of sugars and decomposed products obtained under different reaction conditions ($H_2SO_4$ 0.5-1.25% (w/w), reaction time 0-20 min and temperature range 150-220 C). A careful analytical investigation of acid hydrolyzate of rapeseed straw has not yet been undertaken, and a well-closed mass balance for the hydrolyzate in general is necessary to verify the productivity and economic predictions for this process.

• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.164-171
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• 1999

Microwave-assisted extraction, which is known to rapidly extract target compounds from natural products, was monitored by response surface methodology (RSM) while extracting ginsenosides by using microwave extraction system (MES) equipped with closed vessels, and was confirmed on its extraction efficiency. On the whole, coefficients of determinations $(R^2)$ of the models on ginsenoside contents of extracts with various extraction conditions were above 0.83 (p<0.1). $Ginsenoside-Rb_2,\;-Rc,\;-Re\;and\;-Rg_1$ were maximized in $140^{\circ}C$ of extraction temperature and $50\~75\%$ range of ethanol concentration. Unknown compound peak on HPLC chromatogram observed at extraction temperature over $120^{\circ}C$, increased at the extraction temperature of $150^{\circ}C$. The extraction temperature of $ginsenoside-Rb_2$ and -Re increased from $129^{\circ}C\;to\;147^{\circ}C$ with including unknown compound, and $R^2$ of the models on ginsenoside contents of extracts increased with including unknown compound into ginsenoside $Rb_2$ and Re. Contents of unknown compound were minimized in $67.33\%$ of ethanol concentration, $99.34^{\circ}C$ of extraction temperature and 3.65 min of extraction time. Ginsenoside contents extracted by microwave system for 8 min showed a similar tendency to those of the current extraction method for 40 hrs.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.6
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• pp.64-72
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• 2017

The longitudinal dynamic instability which can occur in the fueling process of a space launch vehicle is called pogo. It is caused by coupling between the fuselage and propulsion system and they would be formed as a closed-loop system. so that the amplitude of the response may increase or decrease. In this paper, a mathematical model which is applicable to the systematic pogo analysis of a general launch vehicle is developed for an example of space shuttle. The formulations are composed of the linearized second-order differential equation for the propulsion system, and of the pressure, weight displacement, and generalized displacement. Those are important parameters for pogo analysis, are derived through eigenvalue analysis. By the formulation suggested in this paper, it is expected that mathematical modeling method of the pogo system can be obtained and systematic pogo stability analysis for any launch vehicle will be enabled.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.48-61
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• 2020

The objective of this study is to estimate traffic capacity based on the heavy-vehicle ratio in a two-lane freeway work zone where one lane is blocked by construction. For this, closed circuit television (CCTV) video data of the freeway work zone was collected, and the congestion at an upstream point was observed. The traffic volume at a downstream point was analyzed after a bottleneck was created by the blockage due to the upstream congestion. A distribution model was estimated using observed-time headway, and the road capacity was analyzed using a goodness-of-fit test. Through this process, the general capacity and an equation for capacity based on the heavy-vehicle ratio passing through the work zone were presented. Capacity was estimated to be 1,181~1,422 passenger cars per hour per lane (pcphpl) at Yeongdong, and 1,475~1,589pcphpl at Jungbu Naeryuk. As the ratio of heavy vehicles increased, capacity gradually decreased. These findings can contribute to the proper capacity estimation and efficient traffic operation and management for two-lane freeway work zones that block one lane due to a work zone.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.221-227
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• 2020

In the case of complete edentulous patients, as the mandibular alveolar bone absorption progresses, the maintenance and stability of the existing dentures, which had satisfactory functions in the past, are deteriorated. Despite of the need to fabricate new dentures, they often hesitate due to physical burdens on the duration and intensity of future treatment progress due to the effects of aging and systemic diseases. In the case of these completely edentulous patients, it is necessary to consider the treatment goals that can reduce the number of visits and the adaptation period for new dentures before starting the treatment. This case is a case of producing complete dentures of elderly patients with deteriorated physical ability. In addition to producing suction dentures through preliminary and definitive closed mouth functional impression suggested by Sato, CAD / CAM technique was used to transfer occlusal functional information of existing dentures to facilitate adaptation to new dentures.

• Convergence Security Journal
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• v.17 no.2
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• pp.173-183
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• 2017

This study is for presenting the factors about success attribution that fit the korean security service conditions and developing the actual analysis of measurement tools by investigating the success factors of the security service agents. To this end, conducted a meeting from the fully open questionnaire at first, and then formed the semi-structured questionnaire, finally carried out the survey from the closed questionnaire and analyzed data from SPSS 21.0, AMOS 21.0 and developed the measurements. It was conducted from December, 2014 to June, 2015. This survey was conducted of 170 security guards after the verification of the content validity though the pilot survey and presented the success attribution factors and standards on the basis of the result form this survey. At the first and second analysis process, the success attribution factors of the guards consisted of inner qualities, external qualities, induction factors for inner qualities, and induction factor for external qualities. On analysis of the final data and documents, however, at the third analysis, the success attribution factors of the guards consisted of 'martial arts and physical ability'(4 questions), 'attitudes to work'(3 questions), 'support for the working environment'(3 questions), 'organized business skills'(3 questions), 'attitudes to the duty'(3 questions), and 'coping with crises(2 questions).

• The Journal of Korean Academy of Sensory Integration
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• v.18 no.2
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• pp.1-14
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• 2020

Objective : This study presents guidelines for setting up a sensory integration room by applying the Delphi method. Methods : The Delphi method was applied in a survey of 22 expert panels asked to review sensory integration therapy from May to June 2020 to collect expert opinions. The survey was conducted in two rounds. The first round involved the collection of opinions based on prior research that used a total of 40 assessment tools, 23 closed questions about treatment tools, and 10 questions about the physical environment. Based on the results of the first round, the second was conducted using a process of item deletion and modification. Results : A total of 59 items were selected in the first round of the survey. In the second the contents of these 59 items were analyzed: each item scored .42 or higher, so no items were deleted. The stability of the survey was also calculated and found to be less than 0.5, so no further testing was required. The average content feasibility ratio of the final Delphi survey was .92, stability .15, convergence .36, and consensus .80, showing high agreement. Conclusion : This study is expected to help institutions and clinical therapists who want to create a sensory integration therapy room in their facilities by examining the physical environment, treatment tools, and evaluation tools used in sensory integration therapy rooms and understanding the views on such environments obtained from the clinical site to sensory integration therapists.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.4
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• pp.222-229
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• 2005

A simplified one-dimensional model STELLA was used to predict soil water movement in lllinois corn fields using soil water balance sheets. It offered the potential to increase understanding of soil nitrate and agrochemical leaching process. The model accounted for aU possible annual inputs and outputs of water from a closed ecosystem as represented by corn fields. Water inputs included precipitation, while outputs included runoff, transpiration, evaporation and drainage. To run the model required daily inputs of two climatic data measurements such as daily precipitation and pan evaporation. Vertical water flow through the soil profile was calculated with first order equation including the difference in hydraulic conductivity and matric potential at the various soil types. The output results included daily changes of water content in the soil layers and daily amount of water losses including run-off, percolation, transpiration. This model was verified using Illinois corn field data for the soil water content measured by neutron scattering methods through 1992 to 1994 growing seasons. Approximately 22 to 78% of simulated water contents agreed with the measured values and their standard deviation, depending on soil types, whereas 30 to 70% of simulated water values agreed with the measured values and their standard deviations depending on soil layers.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.1
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• pp.1-17
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• 2017

This study was conducted to investigate the nutrient distribution and controlling factors in small stream estuaries. The seasonal variations of nutrient concentration (nitrate, ammonium and phosphate) were observed from 2010 to 2012 in the three streams located in Dang-hang (closed estuary: Go-seong, open estuary: Gu-man and Ma-am). The nutrient concentrations in Go-seong were significantly higher than other estuaries, because Go-seong is relatively large and has large nutrient load from the watershed. The dyke located at the estuary, also, caused the high nutrient concentration by reducing the dilution and increasing residence time. In all three streams, nitrate concentration was high at upstream and decreased toward the downstream, because high load of nutrient input were located at upstream. Dilution and biogeochemical removal toward the downstream also caused the trends. Especially, denitrification, a typical nitrogen removing process showed clear tendency of gradual decreasing from upstream to downstream. However, Ammonium and phosphate concentrations were high at upstream and decreased toward the downstream only when the nutrient loads from the rivers were high. Nutrient concentrations were low in summer and high in winter. Freshwater discharge in summer caused a decrease of the residence time and increase of the transport of nutrients to downstream and reduced the nutrient concentrations in the estuary. Nutrient removal by the biological production during high temperature periods also affected the low nutrient concentrations. Small stream estuaries showed distinct nutrient dynamics. It is necessary to understand these characteristics in order to properly manage the small stream estuary.