• Journal of the Korean Geotechnical Society
• /
• v.23 no.8
• /
• pp.149-158
• /
• 2007

Recently, the selection of procurement material for reclamation or road at Pohang area is getting harder. so, it is attempted that mudstones are used for road base material and harbor reclamation. But there is no example that use mudstone to reclamation and the features of the reclaimed land using mudstones have not been made clear yet. We will make clear these features-especially the water absorption and softening, slaking behavior and the geological mechanism, so we will obtain the method to forecast a land subsidence and a decline of land strength. In this study, we examined the adaptedness judgment of mudstones as a reclamation material for road basis material or harbor reclamation material through the laboratory test and pilot test.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.34 no.2
• /
• pp.135-138
• /
• 1998

This paper describes the construction and experimetal results of prototype digital telesounder developed to monitor remotely the fish school entered in setnet. The telesounder consists of the sea station and land station. The former consists of an ultrasonic transceiving part of 50 KHz, a hand made 16 bits single board computer (SBC), and a RF MODEM of 9600 bps for data link. The SBC controls the trigger signal to transmit the ultrasonic pulse, maximum detection range, sampling rate in analog to digital converter and data link. The sampling rate of echo data was 80 ${\mu}$s. The later consists of a RF MODEM same as the former one and 486 notebook computer which displays the echogram and saves its raw data. The authors carried out some experiments to confirm the practical use of the telesounder. At results the echogram obtained on the land station is sufficiently good and clear to monitor the behavior of fish school in setnet.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.22 no.3
• /
• pp.379-385
• /
• 2012

This paper developes the navigation visual aid supporting a watch officer's situation awareness and analyzes its performance test result. Developing the equipment made from composite video sensor which transfer video signal, ranger laser measurement model which search out distance, Pan/ Tilt, center control device. The developed equipment with Pan/Tilt was made from high performance video sensor and ranger laser measurement. To make a real ship test, we carried on setting the developed equipment on ship, observed a danger factor and analyzed a image, and from that we can evaluate marine environment awareness. Through this result, the developed equipment can show effective ability of the awareness of the clearer check and resolution situation when compare with the binocular.

• 대한공업교육학회지
• /
• v.36 no.1
• /
• pp.1-22
• /
• 2011

The purpose of this study was to develop and apply activity-centered STEM education program of electricity and electronics technology are in middle schools. The program was developed on the emphasis of problem solving in real world in relation to knowledge, attitude, and skill of Science, Technology, Engineering, and Mathematics. Basically the activity-centered STEM education program was developed through three steps of preparation, development and improvement. In the preparation stage the fellowing was included: (1) need analysis of student, educator, society (2) selection of integration type (3) analyzing subject matter of electricity, electronics area (4) establishing criteria for selecting activity tasks. In the development stage the fellowing was conducted: (1) selection of activity tasks (2) setting up educational goals (3) analyzing activity and clarifing the detailed activity (4) selecting program content, (5) organization of instructional content (6) statement of instructional objectives (7) structuring STEM education program In the improvement stage the fellowing was consisted of: (1) verification of validity by experts (2) execution of pilot test and field test by students and correction of program. The results of the applied the Activity-Based STEM Education Program to 'Afterschool' activities of S middle school were as follow: First, student' satisfaction level was high. Second, student' achievement in the cognitive domain, and affective domain was positive change. Third, student' problem solving ability was positive effect.

• Journal of the Korean Geotechnical Society
• /
• v.21 no.1
• /
• pp.59-67
• /
• 2005

This paper presents experimental and numerical research results of centrifuge model tests performed to investigate the geotechnical engineering behavior of slag compaction pile as a substitute of sand compaction pile. For centrifuge model tests, bearing capacity of composit soil improved with slag compaction piles, stress concentrations in-between pile and soft clay, settlement characteristics, and failure modes were investigated with slags differing in their relative density. A slag was found to be a good substitute for a sand since the slag compaction pile model showed a greater yield stress intensity up to $30\%$ than the sand compaction pile model under the identical testing conditions. Stress concentration ratio tended to increase with the relative density of slag pile and the clear shear lines in the piles were observed at the depth of $2D{\sim}2.5D$ (D=dia. of model pile) from the top of the piles after loading tests. Numerical analysis with a software of CRISP, implemented with the modified Cam-clay model, was carried out to simulate the results of centrifuge model test. Test results about characteristics of load-settlement curves and stress concentration ratio are in relatively good agreements with numerical estimations.

• Journal of Veterinary Clinics
• /
• v.23 no.3
• /
• pp.340-343
• /
• 2006

A 10-year-old, intact female Beagle dog was presented for examination of acute onset of right-sided head tilt and moderate ataxia. Clinical signs were acutely presented 12 days ago and had been progressively alleviated until the admission day. The dog was bright, alert, and responsive. On neurological examinations, mild head tilt to the right and mild ataxia were noted, thus vestibular disorders were suspected. Central vestibular disease was ruled out based on the clinical signs, magnetic resonance imaging(MRI), and cerebrospinal fluid(CSF) analysis. Otoscopic examination showed that the tympanic membranes were intact and normal in appearance. On radiographic and MR examinations, abnormalities were not found in the tympanic bulla and the petrous portion of the temporal bone. Hypothyroidism was ruled out by thyroid-stimulation hormone(TSH) stimulation test. Clinical signs were completely disappeared at 2 weeks after discharge without any therapy. Thus, the dog was definitively diagnosed as idiopathic vestibular disease based on the clinical signs, excluding other causes of vestibular dysfunction, and the alleviation of clinical signs with time.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.2
• /
• pp.174-179
• /
• 2015

Failure Mode and Effects Analysis (FMEA) has been used by Dynamic Positioning (DP) system for risk and reliability analysis. However, there are limitations associated with its implementation in offshore project. 1) since the failure data measured from the SCADA system is missing or unreliable, assessments of Severity, Occurrence, Detection are based on expert's knowledge; 2) it is not easy for experts to precisely evaluate the three risk factors. The risk factors are often expressed in a linguistic way. 3) the relative importance among three risk factors are rarely even considered. To solve these problems and improve the effectiveness of the traditional FMEA, we suggest a Fuzzy-FMEA method for risk and failure mode analysis in Dynamic Positioning System of offshore. The information gathered from DP FMEA report and DP FMEA Proving Trials is expressed using fuzzy linguistic terms. The proposed method is applied to an offshore Dynamic Positioning system, and the results are compared with traditional FMEA.

• The Journal of the Acoustical Society of Korea
• /
• v.42 no.4
• /
• pp.285-297
• /
• 2023

The present study aims to investigate the acoustic performance of the creative convergence classrooms in Korea used by elementary school students under the age of 9 introduced through the school space innovation project. In order to do this, acoustic performances of three creative convergence classrooms were measured. The measured acoustic parameters were background noise levels, Reverberation Time (RT), D₅₀, Speech Transmission Index (STI), and Inter-Aural Cross Correlation (IACC). Also, acoustic parameters including Transmission Loss (TL) and standardized level difference (D_nT) have been measured for the analysis of sound insulation performance of walls. In addition, the noise level was measured according to the opening conditions of doors and windows in the classroom. As a result, background noise level was measured at an average of 28.0 dB(A) to 32.8 dB(A) when the air conditioner was not operated, and the RT did not exceed 0.6 s. There were differences in IACC according to various desk layouts, and IACC values were high in the center line and the seats near the sound source. In particular, higher IACC was measured at the seats on the center line facing the source squarely. Regarding noise level in the classroom according to the opening conditions of doors and windows, the standards were exceeded when all windows, or windows and doors front onto the corridor were opened.

• Korean Journal of Microbiology
• /
• v.43 no.4
• /
• pp.298-303
• /
• 2007

Antithrombotic activities of water extract of cheongkookjang and cheongkookjang fermented with green tea or mugwort were evaluated on some antithrombosis related activities in vitro and thrombotic death inhibition in vivo. Cheongkookjang made of white soybean (Glycine max) or black small soybean (Rhynchosia nulubilis) showed potent antioxidative activities. Addition of green tea or mugwort during cheongkookjang fermentation increased the antioxidative activity, cheongkookjang with green tea showed more drastic increase compared with cheongkookjang with mugwort. Nitrite scavenging effects of the cheongkookjang extracts were prominent but the addition of green tea or mugwort seldom increased the scavenging effects. All the cheongkookjang extracts showed strong inhibitory activities on platelet aggregation. The inhibitory activities of cheongkookjang were increased considerably by addition of green tea or mugwort even with low concentration. Plasmin unit as fibrinolytic activity was not affected considerably by addition of green tea. Addition of mugwort decreased the activity transiently at low concentration ($0.3{\sim}1.0%$) but increased again slowly at higher concentration ($1{\sim}3%$). In vitro thrombotic death inhibition test, the antithrombotic activity of cheongkookjang made of black small bean with green tea was higher by about 1.5 times compared to that without green tea. As results, cheongkookjang might inhibit antithrombosis not only by fibrinolytic action but also by inhibition of platelet aggregation and antioxidative action. The addition of functional materials such as green tea or mugwort could increase the antithrombotic function, even at low concentration.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.8 no.3
• /
• pp.157-165
• /
• 1975

This experiment was carried out to evaluate the sanitary quality of commercially frozen sea foods. One hundred and sixteen samples in six different items from several refrigeration plant in Busan city were examined from March to December in 1974. In addition, the changes in bacterial density through the process from thawing, round or semifilleted frozen alaska pollack to the finishing as frozen fillet blocks were observed. To evaluate the sanitary quality, sanitary indicative bacteria such as total coliform, fecal coliform, fecal streptococci and enterococci as well as plate counts were determined. From the results, the median value of fecal coliform MPN was 20 per 100 grams of the samples and that of enterococci was 790. The median value of plate counts was $2.2\times10^4$ per gram. The plate counts were not correlated with the number of sanitary indicative bacteria. The results suggest that enterococci could be used advantageously in preference to coliform organisms as indicative bacteria for the evaluation of sanitary quality of frozen sea foods. The plate counts at $20^{\circ}C$ of the samples were 14 times higher than that at $35^{\circ}C$. Geometric mean of total coliform MPN was 310 and that of enterococci was 143. Bacterial density was reduced by fleering. Morethan 50 percent for total coliform MPN and $35^{\circ}C$ plate counts, and about 35 percent for enterococci MPN and $20^{\circ}C$ plate counts were reduced under the contact freezing unit which was generally operated at $-40^{\circ}C$. About fifty-five percent of the samples were negative in fecal coliform test and 10 percent of those were exceeded $1.0\times10^5$ per gram in $35^{\circ}C$ plate counts.