• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.333-338
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• 2019

In the field of radiotherapy, the Quality Assurance(QA) procedure to verify the safety of treatment is considered to be very important. However, due to various problems of the conventional dosimeters used for the QA, researches on these dosimeters have been actively carried out to replace them. In this study, to maximize the sensitivity by visible light(VL) emitted from phosphors, blended hybrid sensors were fabricated by blending various weight percent(wt%) of $Gd_2O_2S:Tb$ which is a phosphor with excellent fluorescence efficiency into $PbI_2$. Then, the electrical properties to high energy radiation from the blended sensors and the pure $PbI_2$ sensor were compared and evaluated. As a result of the sensitivity evaluation, the sensor of 3wt% showed the highest value with more than 40% difference from the other sensors, and gradual decreasing in sensitivity was observed with increasing wt% except for the sensor of 3wt%. Also, in the reproducibility evaluation, the pure $PbI_2$ sensor exhibited a large variation in coefficient of variation(CV)>0.015, while all the blended sensors showed CV<0.015.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.4
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• pp.98-106
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• 2011

Establishing conservation programs to protect and maintain populations of endangered species are not only a global trend, but also a pursuit endorsed by the Korean Environmental Conservation Act. This study evaluates the feasibility of alternative habitat patches for the endangered butterfly Parnassius bremeri. A portion of habitat of P. bremeri is expected to be fragmented and damaged due to the scheduled construction of the Sangju-Yongduk Highway. A trans fer of the habitat patches of P. bremeri is also scheduled. In order to select an alternative habitat patch, the Mark-Release-Recapture (MRR) method was used to simulate a patch transfer model. The connectedness between habitat are as and the survival of local populations were evaluated for each candidate habitat. It was found that metapopulations with patch distances of <250m showed a 50% connectedness and survival rate in local populations. P. bremeri were expected to migrate at an average distance of 300m. In addition, P. bremeri formed a metapopulation that exhibited intimate patch dynamics that promoted persistence among these patches. Possible candidate habitats including those recommended by local governing bodies were evaluated along with habitats that may counter problems arising from the damage done to the original habitat and habitats that may have a compensatory value equal to that of the original habitat. Based on these criteria, Ansa-myeon township office was selected due to its high scores. This scoring was based on a consideration of a wide range of variables that mark a successful transfer of habitat. These include the amount of funding available, the governing bodies of the possible alternative habitat, and the Expected collaborative effort of local citizens. This decision was collaborated on by incorporating the expertise of various fields of study including biology, ecology, biogeography, ecological engineering, landscape architecture, and social sciences. Therefore, it is suggested that in order to evaluate an alternative habitat for organisms, many social issues as well as ecological issues must be considered.

• Journal of Gastric Cancer
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• v.4 no.4
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• pp.230-234
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• 2004

Purpose: The use of laparoscopic surgery for gastric disease has been gaining popularity. However, there has been the controversy over the indications and the standard techniques of laparoscopic gastric surgery in the early gastric cancer (EGC). The purposes of this study were to compare the clinical outcomes among a hand-assisted laparoscopic distal gastrectomy (HALDG), a laparoscopy-assisted distal gastrectomy (LADG), and an open distal gastrectomy (ODG) and to discuss the role of these procedures in the treatment of EGC. Materials and Methods: Between August 2001 and July 2004, laparoscopic surgery was performed in our institution on 25 patients, LADG (n=7) and HALDG (n=18) with EGC. Analysis was performed on clinical data such as the operative time, the hospital stay, the start of oral intake, and the number of harvested lymph nodes. Patients were categorized into early and late groups by using the date of surgery and were also grouped by surgical procedure. To evaluate the feasibility and efficacy of laparoscopic surgery for EGC, we compared the clinical data with those for ODGs performed during the same period. Results: There was no difference in the number of harvested lymph nodes between the laparoscopic group and the open group, but the operation time in the laparoscopic group was longer than that in the open group (P<0.05). Also, no significant differences in other clinical data were found between the two groups. Comparing the early and the late periods of the series, the number of harvested lymph nodes for a HALDS increased from $22.31\pm4.29\;to\;29.40\pm3.21$ (P<0.05). Conclusion: Our early experience with laparoscopic gastric surgery shows that a wide range of possibilities exist for applying laparoscopic gastric surgery to selected gastric cancer patients. However, the surgical procedure should be standardized, and the outcomes of laparoscopic surgery, in comparison to those of open surgery, need to be confirmed based on a large randomized study. (J Korean Gastric Cancer Assoc 2004;4:230-234)

• Progress in Medical Physics
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• v.19 no.4
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• pp.209-218
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• 2008

According to improved radiation therapy technology such as IMRT and proton therapy, the accuracy of patient alignment system is more emphasized and IGRT is dominated research field in radiation oncology. We proposed to study the feasibility of cone-beam CT system using simple x-ray imaging systems for image guided proton therapy at National Cancer Center. 180 projection views ($2,304{\times}3,200$, 14 bit with 127 ${\mu}m$ pixel pitch) for the geometrical calibration phantom and humanoid phantoms (skull, abdomen) were acquired with $2^{\circ}$ step angle using x-ray imaging system of proton therapy gantry room ($360^{\circ}$ for 1 rotation). The geometrical calibration was performed for misalignments between the x-ray source and the flat-panel detector, such as distances and slanted angle using available algorithm. With the geometrically calibrated projection view, Feldkamp cone-beam algorithm using Ram-Lak filter was implemented for CBCT reconstruction images for skull and abdomen phantom. The distance from x-ray source to the gantry isocenter, the distance from the flat panel to the isocenter were calculated as 1,517.5 mm, 591.12 mm and the rotated angle of flat panel detector around x-ray beam axis was considered as $0.25^{\circ}$. It was observed that the blurring artifacts, originated from the rotation of the detector, in the reconstructed toomographs were significantly reduced after the geometrical calibration. The demonstrated CBCT images for the skull and abdomen phantoms are very promising. We performed the geometrical calibration of the large gantry rotation system with simple x-ray imaging devices for CBCT reconstruction. The CBCT system for proton therapy will be used as a main patient alignment system for image guided proton therapy.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.129-138
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• 2007

A natural deodorizing agent (NDA) was made using pine cone byproduct, and its effects on malodor emission and composting were analyzed in this study. NDA was manufactured by mixing pine cone byproduct with three species of microorganisms and water containing mineral nutrients and molasses, and then by incubating for 48 hours at $30^{\circ}C$. Lab scale experiments were done with three treatment groups, T1 (control, sawdust treatment), T2 (microorganisms and sawdust treatment group), and T3 (NDA and sawdust treatment group). During composting, temperatures reached over $55^{\circ}C$, a minimum temperature for the inactivation of pathogenic microorganisms. No differences were found in physicochemical composition of compost among treatments. However, it was observed that over usage of NDA could obstruct temperature increase, since the biodegradation rate of organic matter of NDA was relatively low, Nitrogen loss due to ammonia gas emission, which normally happens during composting, was reduced by using NDA, and hence the nitrogen level of final compost was higher in T3 than in others. During experiment, it was found that ammonia gas emission was entirely lasted through compositing duration, but the $CH_3SH$ and $H_2S$ gases were produced only at early stage of composting. The ammonia concentration trapped in $H_2SO_4$ solution during 31 days of composting in T1, T2 and T3 was 12,660mg/L, 11,598mg/L and 7,367mg/L, respectively, showing distinguishable reduction of ammonia gas emission in T3. The emissions of $CH_3SH$ and $H_2S$ gases were also remarkably reduced in T3. Based on these obtained results, usage of the deodorizing agent made with pine cone byproduct could reduce the emission of malodor during composting, without any deterioration of compost quality.

• Journal of Animal Environmental Science
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• v.17 no.sup
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• pp.61-68
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• 2011

To assess the total cost with all stages of facilities, the feasibility of Life Cycle Cost (LCC) analysis was examined in this study to estimate the livestock manure treatment system and optimal decision making process. For the economic evaluation, the plant/equipment investment and annual operation cost of four Public Livestock Recycling Facilities, whose treatment capacity is 100 ton piggery manure per day, was compared. The initial cost was in the range of 2,699 million won to 3,202 million won, where T and E methods were highest and lowest, respectively. The annual operation cost was in the level of 378 million to 498 million won, which decreased in the following order : T method > J method > E method > B method. For the LCC analysis, 4.7% of interest rate, 3.13% of inflation rate, and 1.52% of net discount rate was considered by the data received from Bank of Korea and Statics Korea in the period of 2000 to 2009. Also, for the calculation of present value factor, the durable years of civil engineering & construction, machinery and electric instrument was 30 years, 10 years and 15 years, respectively. Based on these consideration, operation cost was in the range of 17,570 won/ton to 20,661 won/ton, and E method (17,570 won/ton) was economical and B method (20,661 won/ton) was non-economical. Though initial cost of T method was higher than that of B method, LCC analysis of T method was lower than that of T method due to the lower operation cost. Therefore, LCC analysis, which considers both initial cost and operation cost, is more reasonable evaluation method than either initial cost or annual operation cost. For the change of LCC analysis according to the uncertainty, the sensitivity analysis was carried out using fluctuation magnitude of discount rate in the period of 2000 to 2009. As a result, LCC analysis evaluated by discount rate was stable for the uncertain factors since the cost leadership did not change even though the sensitivity analysis varied. In summary, the economic evaluation using LCC analysis could be an efficient reference to choose the suitable livestock manure treatment plants. Furthermore, standardization of statement calculation for the actual cost analysis should be conducted and more detailed study is necessary to validate this summary. Therefore, the application of comprehensive technology evaluation, which considers LCC analysis, should contribute in obtaining objectivity and enhancing reliability for the 'Evaluation of Livestock Manure Treatment System and its Technology'.

• Progress in Medical Physics
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• v.26 no.4
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• pp.258-266
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• 2015

The modern radiotherapy technique which delivers a large amount of dose to patients asks to confirm the positions of patients or tumors more accurately by using X-ray projection images of high-definition. However, a rapid increase in patient's exposure and image information for CT image acquisition may be additional burden on the patient. In this study, by introducing structural similarity (SSIM) index that can effectively extract the structural information of the image, we analyze the differences between daily acquired x-ray images of a patient to verify the accuracy of patient positioning. First, for simulating a moving target, the spherical computational phantoms changing the sizes and positions were created to acquire projected images. Differences between the images were automatically detected and analyzed by extracting their SSIM values. In addition, as a clinical test, differences between daily acquired x-ray images of a patient for 12 days were detected in the same way. As a result, we confirmed that the SSIM index was changed in the range of 0.85~1 (0.006~1 when a region of interest (ROI) was applied) as the sizes or positions of the phantom changed. The SSIM was more sensitive to the change of the phantom when the ROI was limited to the phantom itself. In the clinical test, the daily change of patient positions was 0.799~0.853 in SSIM values, those well described differences among images. Therefore, we expect that SSIM index can provide an objective and quantitative technique to verify the patient position using simple x-ray images, instead of time and cost intensive three-dimensional x-ray images.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.526-531
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• 2014

This study was carried out to compare the growth characteristics and feed values of the whole crop silage rice from paddy field and reclaimed paddy field. The heading dates of tested varieties was August 8 to August 30 in the paddy field, 1~2 days later than the reclaimed paddy field's August 6 to August 29. Plant height was in the range of 105~135 cm in paddy field, and 97~126 cm in reclaimed paddy field, respectively. The plant height of Mokyang was tallest in the paddy field, but Suwon 544 was tallest in the reclaimed paddy field. The number of tiller per plant of Nokyang was largest in the paddy field. Dry matter (DM) yield of whole crop rice ranged from 15.26 to $23.24MT\;ha^{-1}$ in the paddy field and 11.94 to $18.89MT\;ha^{-1}$ in the reclaimed paddy field. The highest DM yield in both fields was attained by Mokwoo. Comparing with the paddy field, the reclaimed paddy field achieved 78~84% in the DM yield. The crude protein content of varieties was 8.5 to 11.6% in the reclaimed tidal land and 6.7~8.7% in the paddy field. Neutral detergent fiber (NDF) of varieties in both fields ranged from 31.2 to 55.5%. Suwon 544 recorded the highest NDF contents in both fields. All varieties did not show any significant difference in acidic detergent fiber (ADF) which had values ranging from 22.3 to 33.2%. Total digestion nutrient (TDN) was more than 60% overall in both fields. Regarding TDN yield, Mokwoo recorded $16.54MT\;ha^{-1}$ in reclaimed tidal land and $12.69MT\;ha^{-1}$ in the paddy field, which showed the highest figure among the varieties. These results suggest the feasibility for cultivation of the whole crop silage rice in reclaimed paddy field, which showed 80% of the yield compared to paddy field, and implied that Mokwoo would show the most excellent yield and feed value.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.2045-2056
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• 2014

In this study, pressure drop was measured in the pulse jet bag filter without venturi on which 16 numbers of filter bags (Ø$140{\times}850{\ell}$) are installed according to operation condition(filtration velocity, inlet dust concentration, pulse pressure, and pulse interval) using coke dust from steel mill. The obtained 180 pressure drop test data were used to predict pressure drop with multiple regression model so that pressure drop data can be used for effective operation condition and as basic data for economical design. The prediction results showed that when filtration velocity was increased by 1%, pressure drop was increased by 2.2% which indicated that filtration velocity among operation condition was attributed on the pressure drop the most. Pressure was dropped by 1.53% when pulse pressure was increased by 1% which also confirmed that pulse pressure was the major factor affecting on the pressure drop next to filtration velocity. Meanwhile, pressure drops were found increased by 0.3% and 0.37%, respectively when inlet dust concentration and pulse interval were increased by 1% implying that the effects of inlet dust concentration and pulse interval were less as compared with those changes of filtration velocity and pulse pressure. Therefore, the larger effect on the pressure drop the pulse jet bag filter was found in the order of filtration velocity($V_f$), pulse pressure($P_p$), inlet dust concentration($C_i$), pulse interval($P_i$). Also, the prediction result of filtration velocity, inlet dust concentration, pulse pressure, and pulse interval which showed the largest effect on the pressure drop indicated that stable operation can be executed with filtration velocity less than 1.5 m/min and inlet dust concentration less than $4g/m^3$. However, it was regarded that pulse pressure and pulse interval need to be adjusted when inlet dust concentration is higher than $4g/m^3$. When filtration velocity and pulse pressure were examined, operation was possible regardless of changes in pulse pressure if filtration velocity was at 1.5 m/min. If filtration velocity was increased to 2 m/min. operation would be possible only when pulse pressure was set at higher than $5.8kgf/cm^2$. Also, the prediction result of pressure drop with filtration velocity and pulse interval showed that operation with pulse interval less than 50 sec. should be carried out under filtration velocity at 1.5 m/min. While, pulse interval should be set at lower than 11 sec. if filtration velocity was set at 2 m/min. Under the conditions of filtration velocity lower than 1 m/min and high pulse pressure higher than $7kgf/cm^2$, though pressure drop would be less, in this case, economic feasibility would be low due to increased in installation and operation cost since scale of dust collection equipment becomes larger and life of filtration bag becomes shortened due to high pulse pressure.

• Radiation Oncology Journal
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• v.19 no.4
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• pp.301-305
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• 2001

Purpose : This study was peformed for the evaluation of the feasibility and toxicity of hypofractionated radiation therapy for early glottic cancer Methods and Materials : From February 1999 to February 2000, 20 patients with Histologically confirmed Stage I, II glottic cancer were enrolled into this study. There were 18 males and 2 females, the median age of the patients was 59 years. The distribution of stage distribution was as fellows; T1aN0-16 patients, T1bN0-1 patient, T2N0-3 patients. Eighteen patients underwent laryngomicroscopic biopsy only, and two patients underwent laser cordectomy. All patients received radical radiation therapy (2.5 Gy per fraction, 24 fractions, total 60 Gy). Median duration of treatment was 36 days (range $31\~45\;days$). Results : Radiation therapy were well tolerated. Most common acute reactions were odynophagia and hoarseness, and these reactions resolved after radiation therapy. There were one case of RTOG grade 3 odynophagia $(5\%)$, six cases of grade 3 hoarseness $(30\%)$. Response of radiation therapy was evaluated one month after completion of treatment. All patients revealed complete response. During follow up, total three cases of treatment failure were detected. two cases were local recurrence in 10 and 13 months of radiation therapy and one case was local recurrence and distant metastasis in 2 months of radiation therapy. Conclusion : This hypofractionated radiation therapy schedule was feasible and effective for control of early glottic cancer But longer follow up time would be required to assess the long-term disease control and the late complication by shortening radiation therapy duration.