• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2003년도 추계정기총회 및 국제심포지엄
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• pp.165-169
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• 2003

Current volume reduction methods for wasted expandable polystyrene (EPS) foam are summarized and compared each other. Wasted EPS foam has not been recycled effectively because of its large volume to weight ratio. This has prevented from its proper recycling because of high cost of transportation to recycling plant. Successful recycling of wasted EPS foam results directly from successful, i.e. economically and environmentally, volume reduction of wasted EPS foam. This paper deals with various methods for volume reduction methods of wasted EPS foam. Five typical methods of volume reduction are introduced and they are compared each other in terms of expected PS properties after volume reduction, cost effectiveness of each process, possible effects on environment caused by the volume reduction process, and possible recycled products. The methods include thermal, solvent, far infrared and mechanical compaction. Comparison in this paper is made mostly in qualitative manner. The focus in this study is concentrated on summarizing and comparing existing methods of volume reduction for wasted EPS foam.

• 대한방사선기술학회지:방사선기술과학
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• 제46권3호
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• pp.239-246
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• 2023

In this study, we assessed the effect of reduction of tumor volume in the head and neck cancer by using RANDO phantom in Static Intensity-Modulated Radiation Therapy (S-IMRT) and Volumetric-Modulated Arc Therapy (VMAT) planning. RANDO phantom's body and protruding volumes were delineated by using Contour menu of Eclipse™ (Varian Medical System, Inc., Version 15.6, USA) treatment planning system. Inner margins of 2 mm to 10 mm from protruding volumes of the reference were applied to generate the parameters of reduced volume. In addition, target volume and Organ at Risk (OAR) volumes were delineated. S-IMRT plan and VMAT plan were designed in reference. These plans were assigned in the reduced volumes and dose was calculated in reduced volumes using preset Monitor unit (MU). Dose Volume Histogram (DVH) was generated to evaluate treatment planning. Conformity Index (CI) and R² in reference S-IMRT were 0.983 and 0.015, respectively. There was no significant relationship between CI and the reduced volume. Homogeneity Index (HI) and R² were 0.092 and 0.960, respectively. The HI increased when volume reduced. In reference VMAT, CI and R² were 0.992 and 0.259, respectively. There was no relationship between the volume reduction and CI. On the other hand, HI and R² were 0.078 and 0.895, respectively. The value of HI increased when the volume reduced. There was significant difference (p<0.05) between parameters (D_mean and D_max) of normal organs of S-IMRT and VMAT except brain stem. Volume reduction affected the CI, HI and OAR dose. In the future, additional studies are necessary to incorporate the reduction of the volume in the clinical setting.

• Imaging Science in Dentistry
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• 제53권4호
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• pp.313-323
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• 2023

Purpose: This study aimed to investigate the potential factors that could affect the reduction rate of odontogenic cysts following decompression using cone-beam computed tomography (CBCT) for 3-dimensional volumetric analysis. Materials and Methods: The study sample consisted of CBCT images of 41 individuals who underwent decompression of odontogenic cysts at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, between 2010 and 2022. Preoperative and postoperative CBCT results were collected, and a volumetric analysis was conducted to evaluate the differences in the reduction rate and the percentage of volume reduction of cystic lesions based on different parameters. Correlations between these parameters were analyzed to determine associations. Results: In this study, the average time of decompression for odontogenic cysts was 316 days. Males demonstrated a higher reduction rate than females (P<0.05). The reduction rate was directly proportional to initial cyst volume, with higher reduction rates for cysts with large initial volume than those with small initial volume (P<0.05). Spearman's rank correlation coefficient indicated a weak positive correlation between the initial cyst volume and the duration of decompression. Additionally, a strong positive correlation was observed between the initial volume and the reduction rate. Conclusion: Knowledge of the reduction rate of odontogenic cysts is vital for surgeons to evaluate the duration of decompression before enucleation and to determine a definitive treatment plan. Sex and initial lesion volume had significant effects on the reduction rate.

• Radiation Oncology Journal
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• 제29권4호
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• pp.277-282
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• 2011

Purpose: This study was performed to evaluate the change in the lumpectomy cavity volumes before and after whole breast radiation therapy (WBRT) and to identify factors associated with the change of volume. Materials and Methods: From September 2009 to April 2010, the computed tomography (CT) simulation data from 70 patients obtained before and after WBRT was evaluated. The lumpectomy cavity volumes were contoured based on surgical clips, seroma, and postoperative changes. Significant differences in the data from pre-WBRT CT and post-WBRT CT were assessed. Multiple variables were examined for correlation with volume reduction in the lumpectomy cavity. Results: The mean and median volume reduction in the lumpectomy cavity after WBRT were 17.6 $cm^3$ and 16.1 $cm^3$, respectively with the statistical significance (p < 0.001). The volume reduction in the lumpectomy cavity was inversely correlated with time from surgery to radiation therapy (R = 0.390). The presence of seroma was significantly associated with a volumetric change in the lumpectomy cavity after WBRT (p = 0.011). Conclusion: The volume of lumpectomy cavity reduced significantly after WBRT. As the time from surgery to the start ot WBRT increased, the volume reduction in the lumpectomy cavity during WBRT decreased. A strong correlation was observed between the presence of seroma and the reduced volume. To ensure appropriate coverage and to limit normal tissue exposure during boost irradiation in patients who has seroma at the time of starting WBRT, repeating CT simulation at boost planning is suggested.

• Nuclear Engineering and Technology
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• 제42권2호
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• pp.175-182
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• 2010

As part of a fundamental study on the volume reduction of contaminated concrete wastes, the separation characteristics of the aggregates and the distribution of the radioactivity in the aggregates were investigated. Radioisotope $^{60}Co$ was artificially used as a model contaminant for non-radioactive crushed concrete waste. Volume reduction for radioactively contaminated dismantled concrete wastes was carried out using activated heavy weight concrete taken from the Korea Research Reactor 2 (KRR-2) and light weight concrete from the Uranium Conversion Plant (UCP). The results showed that most of the $^{60}Co$ nuclide was easily separated from the contaminated dismantled concrete waste and was concentrated mainly in the porous fine cement paste. The heating temperature was found to be one of the effective parameters in the removal of the radionuclide from concrete waste. The volume reduction rate achieved was above 80% for the KRR-2 concrete wastes and above 75% for the UCP concrete wastes by thermal and mechanical treatment.

• 한국환경보건학회지
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• 제29권3호
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• pp.28-34
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• 2003

This study was performed to compare the effects of chaff and sawdust as bulking materials on temperature, pH, weight and volume reduction and salinity in aerobic composting of food wastes. Volume ratios of food wastes to chaff in reactor of Control, Ch-l, Ch-2, Ch-3 and Ch-4 were 4:0, 4:1, 4:2, 4:3 and 4:4, respectively. Volume ratios of food wastes to sawdust in reactor of Control, Sd-l, Sd-2, Sd-3 and Sd-4 were 4:0, 4:1, 4:2, 4:3 and 4:4, respectively. Reactors were operated for 24 days with 1 hour stirring by 1 rpm and 2 hours aeration per day. The lowering of the volume ratio of food wastes to chaff and sawdust resulted in the reaction at higher reaction temperature and the elongation of the high temperature reaction period. The lowering of the volume ratio of food wastes to chaff and sawdust resulted in faster pH increase. In the volume ratio of 4:3 and 4:4, pH increased faster in food-chaff mixtures than in food-sawdust mixtures. The lowering of the volume ratio of food wastes to chaff and sawdust resulted in faster steady state in the weight reduction rate and the volume reduction rate. The weight reduction rates of chaff mixtures were higher than those of sawdust mixtures, but the volume reduction rates of sawdust mixtures were more higher than those of chaff mixtures. Salinity increased as composting reaction proceeded, due to reduction in mass weight. The final salinity of Control was 2.79%, and the final range of salinities of chaff and sawdust mixtures were 2.18∼2.37% and 1.86∼2.05%, respectively.

• 한국물환경학회지
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• 제22권2호
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• pp.264-270
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• 2006

In this research, volume reduction of activated sludge using electrolysis was studied to find an optimum condition using lab scale experiments. Wasted sludge was treated by electrolysis with controlling current density, chloride concentration, electrode distance, and reaction time. Volume of return sludge was reduced by 9.79% in average while maximum was 16.7%. Sludge volume reduction efficiency was affected by current density and reaction time. It was reversely proportional to the electrode distance. Especially current density was effective on the system performance significantly. Electric conductivity, salinity and COD were increased by electrolysis implying sludge disintegrated and converted to COD in part. An empirical equation for total solid removal efficiency by electrolysis was proposed by multiple linear regression analysis as: $TS_{rem}$(%) = 5.534 ${\times}$ current density (A/l) + 0.178 ${\times}$ reaction time (m) + 2.758.

• 전기학회논문지
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• 제57권12호
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• pp.2208-2212
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• 2008

This paper deals with the cost reduction design of a single-phase line-start permanent magnet(LSPM) motor. Due to high cost of the permanent magnet(PM), cost reduction can be effectively achieved by reducing PM volume. Therefore, motor characteristics according to the PM volume are calculated by using d-q axis equivalent circuit analysis, and the characteristic map is made. In the characteristic map, maximum torque and efficiency are shown according to motor parameters such as back electromotive force(back emf) and inductances; back emf represents the PM volume. Minimum back emf and inductances satisfying output performance are determined in the characteristic map. Then, motor geometry based on the prototype motor is optimized to get the determined parameters using response surface methodology(RSM) and finite element method(FEM). Through the presented cost reduction design, total PM volume is reduced to 32% of prototype model.

• 한국환경복원기술학회지
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• 제6권4호
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• pp.52-61
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• 2003

This study was carried out to analyze the effects of stormwater retention and infiltration pond on reduction of flood peak and volume in a experimentally developed ecological pond. The experimental site has 542$m^2$ watershed area, 1,310mm yearly-averaged rainfall. And the area of the retention pond is 60$m^2$, the maximum water depth is 0.5m, the maximum and average storage is 15$m^3$and 9.3$m^3$d. And the area of infiltration pond is 58$m^2$, and the water depth varies 0.2m~0.5m. The monitoring system consists of one rainfall gage, one Parshall flume and acoustic water level gage, two rectangular weirs and acoustic water level gage for discharge gaging, and one data recording unit. Data from ten storm events in total, three storm events in year 2000 and seven storm events in year 2001, were collected. From the data the evaporation rate was achieved with the water balance equation, and the result shows 5.0mm/day in average. The result from the analysis of the effects on reduction of flood peak and volume, is that 14% reduction of flood volume and 15% reduction of flood peak in retention pond and 49% reduction of flood volume in infiltration pond.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.2.1-2.6
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• 2019

Objectives: This study was aimed to analyze the reducing pattern of decompression on mandibular odontogenic keratocyst and to determine the proper time for secondary enucleation. Materials and methods: Seventeen patients with OKC of the mandible were treated by decompression. Forty-five series of CT data were taken during decompression and measured by using InVivo software (Anatomage, San Jose, Calif) and were analyzed. Results: The expected relative volume during decompression is calculated using the following formula: V(t) = V_initial × exp.(at + 1/2bt²) (t = duration after decompression (day)). There was no significant directional indicator in the rate of reduction between buccolingual and mesiodistal widths. Conclusion: The volume reduction rate gradually decreased, and 270 days were required for 50% volume reduction following decompression of OKC. The surgeon should be aware of this pattern to determine the timing for definitive enucleation. Clinical relevance: The volume reduction rate and pattern of decompression of the OKC can be predicted and clinicians should be considered when treating OKC via decompression.