• Spatial Information Research
• /
• v.19 no.1
• /
• pp.107-116
• /
• 2011

Due to development of environment of wireless Internet, location based services on the basis of spatial data have been increased such as real time traffic information as well as CNS(Car Navigation System) to provide mobile user with route guidance to the destination. However, the current application adopting the file-based system has limitation of managing and storing the huge amount of spatial data. In order to supplement this challenge, research which is capable of managing large amounts of spatial data based on embedded database system is surely demanded. For this reason, this study aims to suggest the lossless compression technique by using the hybrid approach of BytePacking and Lempel-Ziv which can be applicable in DBMS so as to save a mass spatial data efficiently. We apply the proposed compression technique to actual the Seoul and Inchcon metropolitan area and compared the existing method with suggested one using the same data through analyzing the query processing duration until the reconstruction. As a result of comparison, we have come to the conclusion that suggested technique is far more performance on spatial data demanding high location accuracy than the previous techniques.

• Korean Journal of Agricultural Science
• /
• v.37 no.2
• /
• pp.171-175
• /
• 2010

This study was carried out to find the effect on growing media and proper time for water supply in rice seedling stages. Plant height of rice seedling for SIPAN-BRL among current several growing medias was higher in Chuchungbyeo than Ilpumbyeo, and that of root length was higher in check among used growing medias. Fresh and dry weight of shoot and root of two rice cultivar. Water time to absorption on each treatment of growing media concentration took similarly in SIPAN-BNH and check were similar. But 500 minutes did in 100ppm and did 370 and 470minute in 300 and 500ppm, respectively. Wilting time of rice seedling was appeared highly at 300ppm of SIPAN-BRL in Chuchungbyeo and 100ppm of SIPAN-BRL in Ilpumbyeo, while it prolonged at 300ppm in Chuchungbyeo and 500ppm in Ilpumbyeo, respectively. Water content at wilting stage was appeared highly at SIPAN-BRL 500ppm in both Chuchungbyo and Ilpumbyeo, while SIPAN-BNL was high in 300ppm of Chuchung-byeo and Ilpumbyeo, respectively. Plant and root length of SIPAN-BNL treated with 300ppm in 10day-rice seedling were highly appeared, while dry weight of shoot was high at 300ppm SIPAN-BNL.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.14 no.2
• /
• pp.46-53
• /
• 2010

The purpose of this paper is to study combustion characteristics with the different phase of oxidizer in hybrid rocket combustion. HDPE(High Density Polyethylene) as fuel and $GN_2O$(Gas $N_2O$), $LN_2O$(Liquid $N_2O$) as oxidizer were used to perform the experiments. An investigation was performed for a change of the regression rate, pressure of combustion chamber and combustion efficiency according to the variation of oxidizer phase. In case of using $LN_2O$ as oxidizer, the regression rate is not significantly different from using $GN_2O$ as oxidizer. It is considered that combustion energy is much larger than latent heat energy which was used in the evaporation of liquid oxidizer. However propulsion performance efficiency for $LN_2O$ showed lower value than for $GN_2O$. By increasing the flow rate of liquid oxidizer, heat transfer needed for vaporization of liquid oxidizer was increased, which resulted in the growth of combustion instability.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.5
• /
• pp.1125-1134
• /
• 2018

The purpose of this study was comparing the disability awareness of occupational therapists and none therapists, and investigating the disability awareness according to the demographic characteristics of the respondents. The questionnaire was distributed through the online with a questionnaire based on social network service, and analyzed 62 responses of none therapists and 60 responses of occupational therapists. In results, disability awareness was not significantly different between occupational therapists and none therapists(p>.05). But, in subscale of disability awareness item 4 and 7, occupational therapists were significantly higher than none therapists(p<.05). In all respondents, disability awareness was more positive in males than females(p<.05). Also, there was no difference in disability awareness according to presence of disabled persons among family members or relatives(p>.05). However, All respondents who answered 'Yes' in the presence of disabled persons among family members or relatives in responders were significantly higher than those who answered 'No' in item 4(p<.05). There was no correlation between age and disability awareness(p>.05). The authors discussed suggestions in results of this study.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.6
• /
• pp.123-129
• /
• 2018

Recently, there has been a growing interest in the study of treatment of $CO_2$ generated by industrial activities and resource recycling of industrial byproducts. The aim of this study is to investigate the applicability of industrial byproducts that can be used as concrete mixed materials by carbonation curing. For this purpose, the physical and chemical changes of the pastes with research cement(RC), blast furnace slag powder (GGBFS) and circulating fluidized bed combustion ashes (CFBC) were evaluated by carbonation curing. XRD and SEM analyzes were performed to investigate micro-structural changes. As a result, it was confirmed that calcium carbonate, which is a reaction product produced by carbonation curing, filled the space inside the paste and formed a dense micro-structure. Also, as the $CO_2$ curing time increased, it was confirmed that calcium carbonate crystals were grown together to form a dense micro-structure.

• Journal of KIISE:Computing Practices and Letters
• /
• v.8 no.5
• /
• pp.510-519
• /
• 2002

The OpenGIS Consortium has proposed a new web-mapping technology to support interoperability in web GIS environment by developing the specifications of MapServer and GML. In this environment, the MapServer transforms legacy spatial data into GML data, and clients display them on standard web browsers. This web-mapping testbed proposes methods for discovering, accessing, integrating and displaying GIS information except processing of spatial operations which are essential services in GIS environment. This paper proposes the method for executing spatial operations on GML data which are overlays of different map layers in legacy data servers. To support spatial operations on GML data in web GIS environment, this paper designs and implements GDOM based on the W3C's DOM Specifications and OGC's Simple Features Specifications. This paper shows the specifications and implementation of GDOM and the process of spatial operations in web-mapping testbed environment.

• Journal of the korean society of oceanography
• /
• v.31 no.2
• /
• pp.55-63
• /
• 1996

Distribution of suspended particulate matter, dissolved oxygen and major inorganic nutrients along a meridional section ($126^{\circ}$ 33' E) in the Cheju Strait is described along with the hydrographic and current data obtained during April 25-27, 1995. The current measurements was conducted using a vessel-mounted Acoustic Doppler Current Profiler (ADCP). Repeated coverage along an ADCP transect during 25 hours allows to calculate the daily mean along- and cross-strait currents. Measured material concentrations and the mean current speed were used to estimate the flux density (cencentration times current speed) of materials. Two types of depth distibution of flux densities were observed. for nitrate and suspended particulate matter, the depth distribution pattern of materials determines those of flux densities. However, flow patterns determine those of flux densities for dissolved oxygen, phosphate and silicic acid. The total along-strait water volume transport is about 0.3 Sv (1Sv $10^{6}$ $m^{3}/s^{-1}$). The total along-strait material transports are estimated to be 3.1 $${\times} $10^{5}$ $g/s^{-1},$ 2.4 ${\times}$ $10^{6}\;g/s^{-1},$ 7.I ${\times}$ $10^{2}\;mol/s^{-1},$ 3.I ${\times}$ $10\;mol/s^{-1},$ 1.7 ${\times}$ $10^{3}\;mol/s^{-1}$ for suspended particulate matter, dissolved oxygen, nitrate ion, silicic acid and phosphate ion, respectively.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.11a
• /
• pp.243-246
• /
• 2008

The combustion characteristic of solid fuel with chamber pressure were experimentally studied in hybrid combustion. This paper was experimental confirmed whether solid fuel affected not only oxidizer mass flux but also chamber pressure. Poly-Ethylene(PE) was used as fuel, GOX was used as oxidizer. Chamber pressure was controled by nozzle throat diameter 6mm and 9mm. In low oxidizer mass flux, solid fuel regression rate was affected not only oxidizer mass flux but also chamber pressure. As well, the regression rate increase as chamber pressure increase with same oxidizer mass flux.

• The Journal of the Korea Contents Association
• /
• v.18 no.11
• /
• pp.571-580
• /
• 2018

The purpose of this study is to evaluate the productivity of elderly employees over 60 years old and to analyze factors that directly or indirectly affect the productivity of elderly employees, based on empirical facts of HR managers. As a result, the factors that have a positive effect on the productivity of elderly employees were attitude and professionalism. The decline in physical capacity due to aging was recognized as a key factor that negatively affected the productivity evaluation of elderly employees. Among the management strategies to improve the work performance, it has been shown that work placement or job redesign according to physical competency contributes to improving the productivity of elderly employees. Also, providing safety education and communication opportunities among workers has a positive effect on productivity improvement. The results of this study suggest that it is important to improve worker productivity by arranging older workers' work experience to be able to demonstrate their accumulated career and expertise and to create a working environment that takes into account physical competence.

• The Journal of Internal Korean Medicine
• /
• v.40 no.2
• /
• pp.192-200
• /
• 2019

Introduction: The aim of this study is to report the effect of traditional Korean medical treatment on fibromyalgia. Case presentation: A patient with fibromyalgia was treated with acupuncture, pharmacopuncture (Bee venom, Hwangryunhaedok-tang), cupping therapy, moxibustion therapy and herbal medicine for 37 days. To reduce the patient's symptoms, we provided herbal medicine three times a day, as well as acupuncture, pharmacopuncture, cupping therapy and moxibustion therapy once a day for 37 days. To evaluate the results of this treatment, we used the Numeral Rating Scale (NRS), Score of Sleeping Quality (SSQ) and Fibromyalgia Impact Questionnaire (FIQ). After treatment, the patient showed that pain was reduced, the score of NRS was improved, FIQ improved from 91 to 69 and SSQ improved from 3 to 1. No adverse reaction was noted. Conclusion: According to the result, traditional Korean medical treatment can be effective and safe for the treatment of fibromyalgia.