• 보존과학연구
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• s.33
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• pp.33-43
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• 2012

The corrosion phenomena of the iron artifacts was studied by morphology observation and instrumental analysis(EDS, XRD, Raman) with various corrosion factors in oder to verify to confirm the danger of corrosion factors. Corrosion compounds were collected by depositing pure Fe powder(99%) into a HCl, $HNO_3$, $H_2SO_4$, and $H_2O$ solution which contained the corrosion factors. Stereoscopic-microscope observations were then conducted determine the colors and shapes of the collected corrosion compounds, and SEM-EDS analysis was conducted to confirm the corrosion factors and the growth of these compounds. X-ray diffraction (XRD), Raman analyses were conducted to examine the crystal structure and compositions of the created corrosion compounds. The results of the experiment revealed that corrosion speed was faster in an acidic environment and corrosion of HCl and $H_2SO_4$ was greater than that of $HNO_3$. The corrosion compounds of HCl grew into a needle or chestnut-like shape after being affected by Cl- ion, and XRD and Raman analyses detected goethite and lepidocrocite. The corrosion compounds of $H_2SO_4$ was affected by S ion and grew into a slender-needle-like or cylindrical shape, and the XRD and Raman analyses detected goethite and lepidocrocite. The corrosion compounds of $HNO_3$ grew into a spherical or plate-like shape after being affected by O ion and the XRD and Raman analyses detected magnetite and lepidocrocite. Although the corrosion compounds of $H_2O$ grew into a spherical or plate-like shape after being affected by O ion, most of them were observed to have had spherical shapes, and the XRD and Raman analyses failed to detect corrosion compounds in them. It was found in the study that corrosion characteristics and compounds are diversely displayed according to the corrosion factor.

• Food Science and Preservation
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• v.24 no.2
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• pp.230-236
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• 2017

This study was carried out to investigate the effects of ultrasonic thawing on physicochemical characteristics of frozen pork sirloin. To determine the velocity of an ultrasonic thawing machine, $-80^{\circ}C$ frozen pork sirloins were thawed using 132, 580, and 1,000 kHz ultrasonic thawing machines, and the physicochemical properties of pork sirloin thawed with $15^{\circ}C$ tap water and those using the ultrasonic thawing machines were compared. As a result, thawing speed by ultrasonic thawing was three times faster than that of tap water, but drip weight loss rate is increased by about 5% during ultrasonic thawing compared to that during thawing in tap water. However, biochemical properties, such as pH, volatile basic nitrogen, thiobarbituric acid, and total aerobic bacteria, were not improved by ultrasonic thawing. Hunter values, such as total color change and redness, improved slightly after 580 kHz ultrasonic thawing. The hardness and chewiness of the pork sirloin decreased significantly after 580 kHz ultrasonic thawing; however, springiness was not changed. These results indicate that ultrasonic thawing is faster than thawing in tap water, but the physicochemical characteristics of frozen pork sirloin was not significantly improve by ultrasonic sound.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.90-98
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• 2009

Every spring, Korea is always plagued by sandy dust from the western region of China and Mongolia. Yellow sand is causing an environmental problem to Japan and far into the American continent, let alone Korea. At present, the western region of China is going under desertification at a great speed due to climatic change and humans' damaging activities. To cope with this, each country including China is considering ecological restoration of deserts through planting. Accordingly, this research conducted a vegetation survey on Baicheng district which is a representative dry land of western China to obtain a basic data for ecological restoration of a desert. The survey revealed that Setaria viridis which invaded an arid land made a succession into Setaria viridis-Cannabis sativa var. fruderalis community together with Artemisia mongolica-Setaria viridis community due to the increase in salt concentration and alkalization subsequent to dryness. It was also found out that there finally formed Artemisia mongolica community on a flat intense in harsh wind and dryness with the continuous worsening of environmental conditions. There appeared a different type of vegetation on hilly districts where sporadic shade could come into being because the air humidity could be available relatively there. Frequently, typically appearing at the whole survey area, the Tributlus terrestris community was found to make succession into Tribulus terrestris-Cleisrogenes squarrosa community due to the aggravation of soil environment. In addition, with the worsening of the environment at hilly districts, there formed Clesirogenes squarrosa community resistant to dryness, salinity in soil and strong alkalinity. Further, there appeared higher plant life totalling to 62 taxa comprising 58 species and 4 varieties with 27 families and 49 genuses at the whole survey area. Among these, Compositae plants excellent in resistance to environment was surveyed the most, accounting for 27%.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.265-278
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• 1986

This study was attempted to improve the thermal efficiency of 6 kW water-cooled diesel engine on power tiller. The engine performance tests were conducted to find out the effect of cooling water capacity of 2700cc, 2800cc, 2900cc, 3000cc, 3100cc on power, brake specific fuel consumption (BSFC), torque, temperature of cooling water and lubricating oil and friction losses of the engine with D. C. dynamometer. The results obtained in the study are summarized as follows: 1. The performance of the engine tested was adequated to Korea Industrial Standard but actual economy power was 10% higher than the labeled rated power of the engine. The BSFC of the engine tested 297.8g/kW-h which is belong a little higher level than hreign products. The temperature of cooling water was $101^{\circ}C$ which is higher than SAE standard ($88^{\circ}C$) 2. The friction losses of engine tested was 3.656 kW at 2200 rpm of rated rpm (piston speed 6.97m/sec) and is higher than those of foreign products. 3. When the cooling water capacity was increased from 2700cc to 3100cc the power output of the engine was increased from 6.7 kW to 7.13 kW at the rate of 6.4% and also the torque of the engine was increased from 28.85 N.m to 30.76 N.m at the rate of 6.39%. 4. When the cooling water capacity was increased from 2700cc to 3100cc, the BSFC was decreased 6.9g/kW-h from 310.9g/kW-h to 304.1g/kW-h, and after one half hour operation with full load, the temperature of cooling water was decreased $13^{\circ}C$ from $101^{\circ}C$ to $88^{\circ}C$ and also the temperature of lubricant oil was decreased $6.4^{\circ}C$ from $76.7^{\circ}C$ to $70.4^{\circ}C$. 5. The mechanical efficiency was increased from 70.08% to 71.08% when the cooling water capacity was increased from 2700cc to 3100cc.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.101-107
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• 1985

Since most farmers breeding livestocks in Korea is depended on imported feeds, the rate of self-supplying feeds is very important for a stable development of farmers. Therefore, it is considered necessary to increase the rate of self-supplying feeds. In this study, performance tests were carried out with barley and forage to find the design's parameters of hammer for a small size hammer mill which can be driven by 3.7-7.5 kW power tiller being used by most farmers. The revolution speed of hammer mill was 3000 rpm, widths of hammer were 20mm, 30mm, 40mm, and the levels of thickness of hammer were 2mm, 4mm and 6mm. Experimental materials used were barley and forage and screen openings for barley was 4.76mm, and 3.18mm for forage. The study results can be summarized as follows; 1. Results of grinding tests showed that particle sizes were 478-774 microns for barley and 350-434 microns for forage. They were decreased according to the increasing thickness and width of hammer. 2. Fineness modulus of grinded materials were 3.07-3.62 for barley and 2.69-2.93 for forage. They were inversely proportional to thickness and width of hammer. 3. The required power for grinding was 3.8-5.0 kW for barley and 0.9-1.4 kW for forage. The thickness of hammer was more important for less power requirement than width of hammer. 4. Grinding performance of a small size hammer mill was 99-170kg/kWh for barley and 11-21 kg/kWh for forage. The thickness of hammer was an important factor for grinding performance, and inversely proportional to grinding performance. For about 3.2 of fineness modulus, 4 mm thickness was the best, and an optimum width of hammer was 30mm for a small size hammer mill.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.55-63
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• 2004

Purpose : To evaluate the reflection of tumor motion according to the planning CT scan time. Material and Methods : A model of N-shape, which moved aiong the longitudinal axis during the ventilation caused by a mechanical ventilator, was produced. The model was scanned by planning CT, while setting the relative CT scan time (T: CT scan time/ventilatory period) to 0.33, 0.50, 0.67, 0.75, 1.00, 1.337, and 1.537. In addition, three patients with non-small cell lung cancer who received stereotactic radiosurgery In the Department of Radiation Oncology, Asan Medical Center from 03/19/2002 to 05/21/2002 were scanned. Slow (10 Premier, Picker, scan time 2.0 seconds per slice) and fast CT scans (Lightspeed, GE Medical Systems, with a scan time of 0.8 second per slice) were peformed for each patient. The magnitude of reflected movement of the N-shaped model was evaluated by measuring the transverse length, which reflected the movement of the declined bar of the model at each slice. For patients' scans, all CT data sets were registered using a stereotactic body frame scale with the gross tumor volumes delineated in one CT image set. The volume and three-dimensional diameter of the gross tumor volume were measured and analyzed between the slow and fast CT scans. Results : The reflection degree of longitudinal movement of the model increased in proportion to the relative CT scan times below 1.00 7, but remained constant above 1.00 T Assuming the mean value of scanned transverse lengths with CT scan time 1.00 T to be $100\%$, CT scans with scan times of 0.33, 0.50, 0.57, and 0.75 T missed the tumor motion by 30, 27, 20, and $7.0\%$ respectively, Slow (scan time 2.0 sec) and Fast (scan time 0.8 sec) CT scans of three patients with longitudinal movement of 3, 5, and 10 mm measured by fluoroscopy revealed the increases in the diameter along the longitudinal axis Increased by 6.3, 17, and $23\%$ in the slow CT scans. Conculsion : As the relative CT scan time increased, the reflection of the respiratory tumor movement on planning CT also Increased, but remained constant with relative CT scan times above 1.00 T When setting the planning CT scan time above one respiration period (>1.00 T), only the set-up margin is needed to delineate the planning target volume. Therefore, therapeutic ratio can be increased by reducing the radiation dose delivered to normal lung tissue.

• Korean Journal of Weed Science
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• v.11 no.2
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• pp.111-116
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• 1991

This studies were conducted to get the basic information on the growth habits of Scirpus planiculmis F. Schmidt for control in poldered paddy field. The distribution of corm was about 16% in 0-5cm, 66% in 5-8 cm. 18% in 8-10cm depth of underground. The mean depth of total corm distribution was about 6.51cm. Number of rhizomes and dormant buds per corm were one to four, respectively. Number of rhizomes. dormant buds and total buds(rhizome+dormant bud) were 2.34, 2.85 and 5.20, respectively. The phyllotaxy of S. planiculmis was 1/3 and bracteal leaf were showed from first to 4th leaves. The period of propagation to 100 plants from emergence was 58.52 and 48 days for corm seeded on March 25th, b4ay 7th and June 6th respectively. Days to emergence of S. planiculmis from emergence of previous plant was gradually shorted. as order of propagation from corm seeded progressed. The other side, length of rhizome, plant height and diameter of culm was increased. The plant height of S. planiculmis was higher than rice plant from early stage in rice direct seeding culture, and from 30 dats after transplanting in rice transplanting culture. Speed of propagation was faster in rice direct seeding culture than in rice trasplanting culture.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.596-602
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• 1994

To separate and concentrate mucilage from yam(Dioscorea batatas DECNE), yam was dried, microparticulated using impact mill and air-classified at different air classifying wheel speed(ACWS) in classifier. As ACWS increased from 5,000 rpm to 22,500 rpm, the contents of dietary fiber, protein and lipid of air classified microparticles(ACM) increased remarkably. Especially the ACM with ACWS over 15,000 rpm showed 36.41% dietary fiber and 16.66% protein. The dietary fiber and protein components were concentrated to $2.5{\sim}9.0$ times as compared with whole yam powder. Concomitantly the non-fibrous carbohydrate decreased from 88.31% to 16.84. The damaged starch(%), WSI and WAI of ACM of ACWS over 15,000 rpm were $1.5{\sim}3.0$ times higher than those of ACM under ACWS 15,000 rpm. The apparent viscosity of ACM was 0.0800 Pa s over ACWS 15,000 rpm and 0.0080 Pa s under ACWS 15,000 rpm. Judging from viscosity of ACM, the mucilage component of yam was concentrated to 10 times. In conclusion, the optimum process to separate and concentrate the mucilage from yam consisted of the microparticulation to $5{\sim}30{\mu}m$ and the air-classification at ACWS over 15,000 rpm.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.4
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• pp.15-24
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• 2007

The recognition of postal address images is indispensable for the automatic sorting of postal envelopes. The process of the address image recognition is composed of three steps-address image preprocessing, character recognition, address interpretation. The extracted character images from the preprocessing step are forwarded to the character recognition step, in which multiple candidate characters with reliability scores are obtained for each character image extracted. aracters with reliability scores are obtained for each character image extracted. Utilizing those character candidates with scores, we obtain the final valid address for the input envelope image through the address interpretation step. The envelope sorting rate depends on the performance of all three steps, among which character recognition step could be said to be very important. The good character recognizer would be the one which could produce valid candidates with very reliable scores to help the address interpretation step go easy. In this paper, we propose the method of generating character candidates with reliable recognition scores. We utilize the existing MLP(multilayered perceptrons) neural network of the address recognition system in the current automatic postal envelope sorters, as the classifier for the each image from the preprocessing step. The MLP is well known to be one of the best classifiers in terms of processing speed and recognition rate. The false alarm problem, however, might be occurred in recognition results, which made the address interpretation hard. To make address interpretation easy and improve the envelope sorting rate, we propose promising methods to reestimate the recognition score (confidence) of the existing MLP classifier: the generation method of the statistical recognition properties of the classifier and the method of the combination of the MLP and the subspace classifier which roles as a reestimator of the confidence. To confirm the superiority of the proposed method, we have used the character images of the real postal envelopes from the sorters in the post office. The experimental results show that the proposed method produces high reliability in terms of error and rejection for individual characters and non-characters.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.91-98
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• 2014

Purpose : To compare the dosimetry for the left breast cancer treatment between three dimensional conformal radiation radiotherapy (3D-CRT) and Hybrid planning and to estimate usefulness of Hybrid planning Materials and Methods : Five patients with left breast cancer were included in the study. They were planned using several different radiotherapy techniques including: 1)open rectangular field, 2)tangential wedge-based field 3)field in field, 4)hybrid planning(energy, wedge combine). For each patient planning was using Light Speed RT-16 CT and PINNACLE planning system-ver.9.2. Hybrid plan was made using same system and using the same targets and optimization goals. We comparing the Homogeneity Index(HI), normal organs at the does-volume histogram(DVH) Results : In all plans, the Homogeneity Index(HI) of Hybrid planning was significantly better than other. Dose comparison of HI= 2D-RT:38.32, TW:38.32, FIF:29.22, HYBRID:30.57. 2D-RT, TW, FIF Hybrid$V_{75_-lung}$=112.33, 125.14, 121.3, 123.78. $V_{50_-lung}$=155.43, 159.62, 157.96, 159.06. $V_{25_-lung}$=199.86, 200.22, 198.65, 200.31. $V_{50_-heart}$=26.07, 27.1, 26.85, 27.17 $V_{30_-heart}$=33.71, 34.37, 34.15, 34.65 Conclusion : In summary, 3D-CRT, Hybrid planning techniques were found to have acceptableCTV coverage in our study. However the Hybrid planning increased radiation dose exposure to normal tissue. If you apply for treatment of inhomogeneity areas like lung, For best results will be achieved.