• Journal of Gifted/Talented Education
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• v.26 no.2
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• pp.405-421
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• 2016

The purpose of this study was to investigate students' perception of Advanced Placement Program. Participations of this study were 1144 students from 14 science high schools. The results showed as follows. First, students perceived positively regarding AP program and were willing to take AP courses because of interesting and challenging in academic area which is provided by AP courses. Secondly, many students would like to take AP courses in Differential and Integral Calculus 1, General Physics I, General Chemistry I and General Biology. Also, they would like to take AP courses in first term as a mandatory subjects. Third, responses perceived that AP courses were challenging, difficult, and of high quality. Finally, students perceived the benefit of AP courses in earing college credit. However, 35% of responses wished to receive an exemption for all AP courses. Also, they wished to have dual-major or participate in students exchange program as a benefit of AP program. Implications of the study were discussed in depth based on the results.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.1
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• pp.46-55
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• 2009

To compare and evaluate the suitability and comfort levels of the environment on board a stern trawl training ship, KAYA(GT: 1737 tons, Pukyong National University), with the international standardization guide ISO 6954:2000(E), measurements of the hull vibration on accommodation areas and working areas of the training ship from July 8 to July 10, 2008 were completed upon KAYA's linear sea route. The vibrations along the z-axis were measured with the use of a 3-axis vibration level meter, which included a marine vibration card. Results show accelerations of the vibrations on the passenger's accommodation area to be 42.0-115.8(average: 78.0, standard deviation(SD): 21.0) mm/$s^2$, which is largely below the permissible upper limit, but 75 % of the observation points exceeded the permissible lower limit of 71.5 mm/$s^2$, indicating a comfortable environment. The accelerations of the vibration in a frequency of 10-24Hz lowering the visual performance were measured at 2.5-12.0(average: 7.6, SD: 3.1) mm/$s^2$. The crew s accommodation area experienced vibration accelerations of 42.9-82.3(average: 93.1, SD: 53.1) mm/$s^2$, which is generally below the permissible upper limit of 214.0 mm/$s^2$, and 62.5% of the observation points did not exceed the permissible lower limit of 107.0 mm/$s^2$, denoting a level of comfort. The acceleration of the vibration in a frequency of 10-24Hz were 4.7-28.3(average: 12.4, SD: 8.8) mm/$s^2$. On the crew s working area the accelerations were measured at 86.9-153.9(average 119.3, SD 18.0) mm/$s^2$. These values were generally below the permissible upper limit of 286.0 mm/$s^2$ and only 12.5% of the observation points did not exceed the permissible lower limit of 143.0 mm/$s^2$, the level at which a high level of comfort is maintained. The accelerations in frequency of 10-24Hz and 30Hz were 9.1-29.8 (average 13.8, SD= 4.5) mm/$s^2$ and 8.9-13.7 (average 11.8, SD 2.1) mm/$s^2$, respectively. In conclusion the boarding environment of the training ship was good in general although an improvement of the vibration condition partially needed on the crew s accommodation area near the engine room.

• Journal of Korean Ophthalmic Optics Society
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• v.2 no.1
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• pp.61-76
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• 1997

In this paper, we found out the objective refractive errors, the full corrective refractive powers, and the prescriptions for 64 males and 36 females aged 18 to 26 years. To increase the unaided visual acuity 0.1 to the aided visual acuity 1.0 with the glasses, we needed the spherical equivalent refractive power of -3.00D for male and -2.91D for female respectively. To increase the unaided visual acuity 0.5 to the aided visual acuity 1.0 with the glasses, we needed the spherical equivalent refractive power of -0.5D for male and -1.38D for female respectively. Comparing unaided visual acuity and corrective refractive power, the more one has refractive error the less one has unaided visual acuity but these are not linear relationships. Comparing objective refractive error figures, full corrective refractive power figures and prescriptions, objective refractive error figures are the hightest, followed by full corrective refractive power figures. Prescriptions compared with the other two are lower. The cylindrical refractive powers are less than -2.50D. In this study, with the rule astigmatism is dominant over against the rule astigmatism and oblique astigmatism. The accommodation measured by push up method is 6.75D~10.04D for male and 7.50D~9.60D for female respectively.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.27-35
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• 2015

This study aims to establish the age of the Cretaceous Togeum Formation in Gurye that reported the discovery of dinosaur eggshells and bones. This study also investigates to determine the period of the dinosaurs' dominance in the region. K-Ar ages are measured on the whole volcanic rocks in the lower - and upper parts of the formation. The six samples dated are volcanic pebbles deposited in the Geumjeongri Conglomerate that is distributed underneath the Togeum Formation, and the ages dated as Aptian ($118.3{\pm}2.3Ma$) or Albian ($103.6{\pm}2.0$, $102.5{\pm}2.0$, $99.9{\pm}1.9Ma$), which all correspond to the Early Cretaceous. In addition, the ages of andesites and porphyritic andesites overlying the Togeum Formation are dated in a similar way. The result is that the ages are apparently corresponding to the Campanian ($83.9{\pm}1.6$, $74.2{\pm}1.5$Ma) of the Late Cretaceous. Field evidence and the age results indicate that the formation of the Togeum and the activities of dinosaurs dated back between 84 and 100Ma. It suggests that the Togeum Formation be somewhat older than the Boseong Seonso Formation (81Ma) which contains egg shells, the Haenam Uhangni Formation (79-81 Ma) that has dinosaur, pterosaur and webbed bird footprints, and also older than the theropod egg nests (77-83Ma) found in the Aphaedo area.

• Journal of Environmental Health Sciences
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• v.29 no.2
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• pp.50-55
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• 2003

3,3-dichlorobenzidine is suspected to be cancinogenic in experimental animal and human. Several studies have investigated excretion of metabolites in urine, hemoglobin adduction and cancer incidence among workers occupationally exposed to 3,3'-dichlorobenzidine. In these researches, metabolites of 3,3'-dichlorobenzidine had a very important role, and were required as highly purity. The purpose of this study was synthesis and isolation of its metabolites from 3,3'-dichlorobenzidine. 3,3'-dichlorobenzidine was partially dissolved in benzene, ether, ethanol and methanol, and completely dissolved in 70% acetic acid on mixtures of citric acid containing less than 1% DCB, pyridine, a mixture of 0.5N NaOH and toluene(1:2), and phenol saturated with 20 mM TRIZA base. DCB, monoacetyl-DCB and diacetyl-DCB were measured by using gas chromatography/mass spectrometry(GC/MS). Detection for checking them was nitrogen phosphorous detection mode(NPD), and for identifying them was selected ion monitoring mode(SIM). The base peaks were 252 m/z in DCB, 252, and 294 m/z in monoacetyl-DCB, and 252, 294 and 336 m/z in diacetyl-DCB, respectively. Diacetyl-DCB was synthesized by titrating DCB solution of pyridine with sufficient acetyl chloride. Precipitation was diacetyl-DCB, which was purity of 98.7%. And its supernatant was composed of DCB, monoacetyl-DCB and diacetyl-DCB. By using acetic acid as controller of acetylation, monoacetyl-DCB was isolated from diacetyl-DCB . And residual pyridine was removed by using acetone. The purity of monoacetyl-DCB was 98.8%.

• Korean journal of food and cookery science
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• v.30 no.2
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• pp.193-199
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• 2014

The purpose of the study was to investigate the quality characteristics and sensory properties of fresh and boiling pork shoulder at different feed ration of zeolite (0, 0.5, 1.0 and 2.0%). All of the dietary zeolite groups had significantly higher pH than the control; 0.5% zeolite (6.14) had the highest pH. Cooking loss was significantly higher in the control compared to other treatments; further, the loss, increased as the feed ratio of zeolite addition increased. The cooking loss of fresh pork shoulder fed with 0.5% zeolite (22.47%) was significantly lower than other treatments. The dissolution crude lipid of 0.5% zeolite was the lowest, but was not significant. In the Hunter's color value of fresh pork shoulder, the L and a values were significantly higher in 0.5% zeolite compared to other treatments, whereas the b value was significantly higher in 2.0% zeolite. In the Hunter's color value of boiling pork shoulder, the L and b values with 0.5% zeolite were significantly higher compared to other treatments; however, the a value was not significantly different between groups. The hardness, springiness, cohesiveness, gumminess and chewiness of fresh pork shoulder were significantly increased as the feed ration of zeolite increased. These properties, except for springiness in boiling pork shoulder were significantly increased as the feed ration of zeolite increased. Furthermore, sensory characteristics of color, taste, flavor, appearance and overall preference were significantly higher in boiling pork shoulder with 0.5% zeolite compared to other treatments. Also, texture preference, which was decreased as the feed ratio of zeolite increased, was higher in the control compared to other treatments. In conclusion, the quality characteristics and sensory properties of pork shoulder meat were enhanced with the dietary supplementation of zeolite.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.2 no.1
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• pp.11-23
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• 1991

The main purpose of this study was to investigated the relationship between test anxiety and academic performance, additionally to examine the sexual and developmental differences in test anxiety. Test anxiety was assessed by the TAI-K(Kim Moonjoo, 1990) and was done to 388 3rd, 4th, 5th, 6th, grades and 104 9th grades. The level of TAI-K scores devided into a threeway split or five-way split. In the case of elementary school, four main cognitive subject-areas makes(the mean sum of semester) were used as academic performance indicator and with secondary school, all twelve subject-areas were included. The data were processed by correlational analysis and one-way ANOVA. The Results of this study are as follws : 1) Test anxiety correlated negatively and significantly with academic performance. While in the case of elementary school, in four cognitive subject-areas(Korean, Mathmatics, Society and Physics), two variables showed negative relationship, it was shown negatively in six subject-areas among twelve by secondary students. 2) In the area of sexual differences in test anxiety, female showed significantly higher level than male in elementary school however, there were no significant differences in secondary school. 3) In the area of developmental differences in test anxiety, in the case of elementary school. there were no significant differences between four grades.

• 전자공학회논문지 IE
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• v.49 no.1
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• pp.12-17
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• 2012

Fast development of ubiquitous technology prompted the broadening of the related application area. Application of ubiquitous techniques and system into the construction sites may give us many benefits. There are always a lot of hazard situations in construction sites, and the falling is known to have the high accident rate. To prevent the falling, there has been a lot of efforts including safety education and use of safety gears. In this study, we designed, fabricated and tested a system that can monitor the worker's safety and location informations in real time by using the wireless technology of TOA and RSSI. We used ATmegal28 that is popular in the industrial equipments as MCU and NanoPan 5357 module from Nanotron and CC2500 chipset from TI for radio circuits. We also used 3-axis accelerometer and pressure MEMS sensors to obtain the environmental information, and therefore to aquire the informations of the worker's movement and altitude. We used Labview software from National Instrument to monitor and control the system. We developed the system to send the warning alarms to the server operator and the workers when the workers in the danger zone did not wear the safety hook.

• The Journal of Engineering Geology
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• v.23 no.3
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• pp.235-246
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• 2013

P-wave velocity was measured by the low frequency flaw detector in order to analyze the weathered state of a halo stone Buddha, Unju temple, Hwasun, Korea. By the results of laboratory tests on a fresh acidic tuff with the same rock of a halo stone Buddha, average absorption, average P-wave velocity, and average uniaxial compressive strength were 5.38%, 4,008 m/s, and 70.1 MPa, respectively. The results correspond to moderately strong rock. Average P-wave velocity of a halo stone Buddha measured by the low frequency flaw detector was 2,257 m/s in the left zone, 3,437 m/s in the right zone, and 2,802 m/s overall. Weathering index of a halo stone Buddha was 0.45 in the left zone, 0.21 in the right zone, and 0.33 overall. Comparing the results of a halo stone Buddha with them of laboratory tests, weathered state of a halo stone Buddha was analyzed highly weathered state in the left zone and moderately weathered state in the right zone. Furthermore, it suggests that the left zone of a halo stone Buddha was affected weathering more than the right one. Overall a halo stone Buddha corresponds to moderately weathered state of weathering degrees. In conclusion, it is considered that low frequency flaw detector may be applicable as a valuable method on analyzing the P-wave velocity of the stone cultural heritage with an irregular surface.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.1
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• pp.39-46
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• 2015

In this paper, a gas sensor using a modified $90^{\circ}$ hybrid coupler structure with conducting polymer which operates at 2.4 GHz is represented. Conducting polymers are used to the gas sensing material in proposed sensors. The conducting polymer varies its electrical property, such as work function and conductivity corresponding to the certain gas. To verify this variation of electrical property of conducting polymer at microwave frequencies, the conducting polymer is incorporated with the $90^{\circ}$ hybrid coupler structure, and this proposed sensor operates as reflection type variable attenuator and variable phase shifter. The conducting polymer is employed as impedence-variable transmission lines that cause a impedance mismatching between the general transmission line and conducting polymer. The experiment was conducted with 100 ppm ethanol gas at temperature of $28^{\circ}C$ and relative humidity of 85 %. As a result, the amplitude deviation of $S_{21}$ is 0.13 dB and the frequency satisfying ${\angle}S_{21}=360^{\circ}$ is shifted about 2.875 MHz.