• Journal of the Korean Institute of Navigation
• /
• v.17 no.3
• /
• pp.49-55
• /
• 1993

This study describes the accuracies of position fixes observed by the DGPS systems for the purpose of obtaining the utility basic data in the fishery and oceanography observation field. The circling sail experiments around a reterence point using the DGPS were made in water level point of National Fisheries University of Pusan and on the sea in Yongho day located on the southeast of that university. The main results are as follows ; 1) The number of the usable satellites in position fixing were all eighteen, SV 2, 3, 11-21, 23-26 and SV 28 etc. Each satellites could be observed for average seven hours a day, and position fixing was found to be always possible except about thirty minutes a day. 2) In the standard fixed position, the radius of 95% probability circle and the shifted distance between the position fixes by the DGPS and true position were respectively 5.7m, 0.9m. In the above case those of ordinary GPS was respectively 48.8, 54.2m. Therefore, the accuracy of the position fixes by DGPS was shown much higher the ordinary GPS. 3) At land, the shifted distance between the center of traces in the circling sail experiment of 15m ra-dius by DGPS and the reference position amounted to 5.5m and observed radius of circling traces was 17.5m. other than 15m. At sea, that distance the center of traces in circling experiment of 20m radius by the DGPS and the reference position amounted to 3.6m and observed radius of circling traces was 19.7m, other than 20m. Therefore, the utility of the circling experiment to obtain the accurate position fixes by the DGPS was found to be very high.

• Journal of the Korean Wood Science and Technology
• /
• v.10 no.3
• /
• pp.168-179
• /
• 1982

The first step to utilize the growing resources of Italian poplar (Populus euramericana I-476) for pulp-Woods, its characteristics and adaptabilities to the pulp industry must be investigated completely. The plantation methods are important for its fast growing in stock, and no less important is the cutting age for its utilization as pulpwood. In this paper, the stone groundwood pulping, refiner groundwood pulping and chemi-groundwood pulping characteristics by the age of tree, along with their physical and chemical characterstics were tested, and relationships between the age groups were analyzed to find out the optimum felling age. The results obtained are as follows: 1. The coefficient of pliability was a little higher in the case of younger trees. 2. The water retention value of each pulp was directly proportional to its physical strength, but this tendency was not detected between the age groups of sample woods. 3. Generally, the physical strength of younger wood pulp was lower regardless of the pulping process. But in the case of pretreatment with NaOH, Asphund and CGP pulp from 5 year old sample wood were stronger in physical strengths than those of GP and Asplund pulp with no pretreatment from 10 years old sample wood. 4. The tear factor of Asplund pulp with alkali pretreatment was higher than that of CGP pulp but the breaking length and the burst factor was similar in all processes. Considering the pulp yield and its brightness, CGP process seems to be advantageous. 5. The dissimilarity of physical strength between 7 and 10 years old wood pulp was not very large in all pulping processes but the physical strength of 5 year old wood pulp was very weak. In the of groundwood pulping from Italian poplar woods, 5 year old wood pulp should be mixed with other long fiber pulp for making a good paper.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.445-448
• /
• 2018

In this paper, we design microstrip antenna for GPS / WiFi for broadband mobile communication. The proposed antenna is designed to be used in the FR-4 (er = 4.3), the size is $40mm{\times}50mm$, and it can be used in the GPS frequency band of 1.6GHz and the WiFi frequency band of 5GHz. 2014, and the simulation result shows that the gain is 1.909dB at 1.6GHz and 4.607dB at 5GHz. The S-parameter also showed a result of less than -10dB (WSWR2: 1) in the desired frequency band. Recently, it is expected that GPS navigation system, which is widely used in smart phones and tablet PCs, can be easily and conveniently used by combining and applying GPS with WiFi.

• Korean Journal of Veterinary Service
• /
• v.24 no.4
• /
• pp.359-367
• /
• 2001

A serological survey was performed to establish basic data for the prevalence of antibodies to some major diseases of domesticated boar serum samples from January to December 2000. Sera collected in breeding farms in Gyeongbuk province were tested for Aujeszky's disease virus(ADV), Porcine reproductive and respiratory syndrome virus(PRRSV), Porcine parvovirus(PPV), Japanese encephalitis virus (JEV), Bordetella bronchiseptica(B bronchiseptica), Mycoplasma ; APP), Toxoplasma, and Brucella. There was no antibody to ADV in domesticated boars serum samples detected by Anti-ADV-gpI assay kit. Sero-positive samples to PRRS by IFA were 0.9%(3/330) The HI titers to PPV ranged variously from less than 10 to over 1,280. Two hundred ninety-four out of 330 tested sera showed HI titer of less than 10. In HI test to JEV, 90.3% of the sera (298/330) were below 10. The majority of the serum samples had low prevalence of the antibody B bronchiseptica. ELISA titers to M hyopneumoniae ranged variously from $\leq$ 10 to $\geq$ 1,280. Antibody titers to A pleuropneumoniae type 2(APP2) and type 5(APP5) were 58.2% and 52.7%, respectively, and the tested samples showing ELISA antibody titers of less than 20. There was no significant geographical difference between APP2 and APP5 in this study. In the antibody test of Toxoplasma, 11.5%(38/330) were positive and samples were all negative in sera test of Brucella.

• Journal of Navigation and Port Research
• /
• v.38 no.2
• /
• pp.121-126
• /
• 2014

This paper suggests a new algorithm to provide low-cost GPS modules with DGPS service, which corrects the error vector in the already-calculated position by projecting range corrections to position domain using the observation matrix calculated from the satellite elevation and azimuth angle in the NMEA GPGSV data. The algorithm reduced the horizontal and vertical RMS error of U-blox LEA-5H module from 1.8m/5.8m to 1.0m/1.4m during the daytime. The algorithm has advantage in improving the performance of low-cost module to that of DGPS receiver by a software update without any correction in hardware, therefore it is expected to contribute to the vitalization of the future high-precision position service infrastructure by reducing the costumer cost and vender risk.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.11 no.4
• /
• pp.315-321
• /
• 2017

This paper is a study on the design and realization of Pedestrian navigation service system for the visually impaired. As it is an user interface considering visually impaired, voice recognition functioned smartphone was used as the input tool and the Osteoacusis headset, which can vocally guide directions while recognizing the surrounding environment sound, was used as the output tool. Unlike the pre-existing pedestrian navigation smartphone apps, the developed system guides walking direction by the scale of the left and right stereo sound of the headset wearing, and the voice guidance about the forked or curved path is given several meters before according to the speed of the user, and the user is immediately warned of walking opposite direction or proceeding off the path. The system can acquire stable and reliable directional information using the motion tracker with the dynamic heading accuracy of 1.5 degrees. In order to overcome GPS position error, we proposed a robust trajectory planning algorithm for position error. Experimental results for the developed system show that the average directional angle error is 6.82 degrees (standard deviation: 5.98) in the experimental path, which can be stated that it stably navigated the user relatively.

• Journal of the Korean Chemical Society
• /
• v.41 no.2
• /
• pp.77-81
• /
• 1997

The transport rates of transition metal cations were increased in order of Ni(II)$(NtnOenH_4)$and 1,12,15-triaza-3,4;9,10-dibenzo-5,8-dioxacyclo-heptadecane$(NdienOenH_4)$as carriers. The transport rates of transition metal cations was found to be of first order to the salt concentrations. It was also found that the dissociation process in the transport process is rate determining step. From the measurements of the transport rates at various temperatures, the partition free energies of hydration$({\Delta}G_p)$for the transition metal cations were calculated. The results showed that the order of transport rates of transition metal cations was found to be proportional to the magnitudes of negative value of the partition free energies of hydration$({\Delta}G_p)$.

• Journal of Mushroom
• /
• v.3 no.1
• /
• pp.24-30
• /
• 2005

To study the cultural characteristics and wood rotting ability of the secondary mycellia of Armillaria mellea, it was cultivated on the various media. The optimal mycelial growth condition was 20~27 and pH 5.0~6.5 on PDB. A. mellea grew well on MEA, PDA and GP. Lactose and mannitol as carbon sources and glutamic acid as nitrogen sources were found to be effective as additives. A. mellea employed in this study have the characteristics of white rot types. Pine and oak wood were selected as candidates for sawdust substrate.

• Journal of Advanced Navigation Technology
• /
• v.17 no.6
• /
• pp.600-608
• /
• 2013

The great Tohoku-oki earthquake which occurred on March 11, 2011, caused crustal movements in both Korea and Japan. This study attempts to analyze velocity changes of crustal movement of Korea Peninsula due to the Tohoku-oki earthquake and to compare the calculation with precious crustal movenents of Korea Peninsula. We found that the crustal movement velocity of South Korea increased 3.9 mm/yr northward and 7.5 mm/yr eastward on average as a result of the Tohoku-oki earthquake; when this figure is compared with the past crustal movement velocities of the Korea Peninsula.

• Korean Journal of Materials Research
• /
• v.14 no.9
• /
• pp.607-613
• /
• 2004

This study was to investigate the surface properties of electrochemically oxidized Ti-6Al-7Nb alloy by anodic spark discharge technique. Anodizing was performed at current density 30 $mA/cm^2$ up to 300 V in electrolyte solutions containing $DL-{\alpha}$-glycerophosphate disodium salt hydrate($DL-{\alpha}$-GP) and calcium acetate (CA). Hydrothermal treatment was done at $300^{\circ}C$ for 2 hrs to produce a thin outermost layer of hydroxyapatite (HA). The bioactivity was evaluated from HA formation on the surfaces in a Hanks' solution with pH 7.4 at $36.5^{\circ}C$ for 30 days. The size of micropores and the thickness of oxide film increased and complicated multilayer by increasing the spark forming voltage. Needle-like HA crystals were observed on anodic oxide film after the hydrothermal treatment at $300^{\circ}C$ for 2 hrs. When increasing $DL-{\alpha}$-GP in electrolyte composition, the precipitated HA crystals showed the shape of thick and shorter rod. However, when increasing CA, the more fine needle shape HA crystals were appeared. The bioactivity in Hanks' solution was accelerated when the oxide films composed with strong anatase peak with presence of rutile peak. The increase of amount of Ca and P was observed in groups having bioactivity in Hanks' solution. The Ca/P ratio of the precipitated HA layer was equivalent to that of HA crystal and it was closer to 1.67 as increasing the immersion time in Hanks' solution.