• Journal of Korean Society for Atmospheric Environment
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• v.13 no.5
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• pp.383-396
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• 1997

Numerical prediction of the pollutant dispersion over a two-dimensional hilly terrain is presented. The dispersion model used in the present work is based on the gradient diffusion theory and the finite-volume method on a non-orthogonal boundary-fitted grid system. The numerical model is validated by comparing the results with the available experimental data for the flat-floor dispersion within a turbulent boundary-layer. The numerical error analysis is performed based on the guideline of Kasibhatla et al.(1988) for the elevated-source dispersion in the flat-floor boundary layer having a power-law velocity and linear eddy-diffusivity profile. The influences of the two-dimensional hilly terrain on the dispersion from a continuously released source are numerically investigated by changing the emission locations and heights. It is found that the distributions of ground-level concentration are strongly influenced by the source location and the emission height. Hence, the terrain amplification factor is greatly enhanced when the pollutant source is located within a flow separation region. Dispersion from a source of short duration is also simulated and the duration time of the pollutant is compared at several downstream locations on a hilly terrain. The results of the numerical prediction are applied to the evaluation of environmental impacts due to the automobile exhausts at the seashore highway with a parallel mountain range.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1710-1713
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• 2002

Recently, the pulsed power system has been used to many applications. Such as remediation of environmental hazards, food sterilization, air pollution control E/P (Electrostatic Precipitator), DeNOx/DeSOx power system, ozone generator, high energy physics, and other power source applications. A pulse energy efficiency for load depends on the rising time, peak value. Pulse duration and impedance matching etc. The pulsed power system generally required for short pulse duration and high peak value was forced to consider its volume and economy. In this paper, we investigated operating characteristics of the CO2 laser using an inductively pulsed power system.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.4
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• pp.423-426
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• 2023

Backgrounds/Aims: Patients who undergo pancreatic surgery with venous resection have high rates of morbidity/mortality. Also, they are high-risk for postoperative venous thromboembolism. Whether this group should be routinely anticoagulated is unknown. This study aimed to establish current anticoagulation practices. Methods: A survey (https://form.jotform.com/220242489107048) was sent out to pancreatic surgeons. Questions covered center volume, venous resection/reconstruction techniques and anticoagulation policies. Results: Sixty-five centers from 17 countries responded. Following a "side-bite" venous resection with a patch repair, 40% used an autologous vein patch, 27% used peritoneum, and 27% used a bovine patch. After formally resecting a segment of vein, 17% of centers used an interposition graft (IG). Left renal vein (41%) and polytetrafluoroethylene (73%) grafts were the most commonly used autologous and prosthetic IGs, respectively. Following a prosthetic IG, an autologous IG, and a "side-bite" resection, 59%, 28%, and 19% of centers provided therapeutic anticoagulation, respectively (66% used low molecular-weight heparin). The duration of therapy provided varied from inpatient stay only (14%) to six months (32%). Conclusions: Our global survey indicates that anticoagulation practices are highly variable. Centers do not agree on when to anticoagulate, how to anticoagulate, or the duration of therapy. A robust trial is required to provide clarity.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.4
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• pp.729-743
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• 2024

This research explores consumer preferences for materials in different clothing product categories, using web-crawling and text mining techniques. Specifically, the study focuses on the material-related terms found in consumer reviews across three distinct product categories: functional clothing, formal shirts, and knit sweaters. Top-selling products within each category were identified on the Naver Shopping website based on the volume of reviews, and the four most-reviewed products were selected. Six hundred reviews per product were analyzed using the Textom big-data analysis software to determine the frequency of material-related mentions and word associations. The analysis utilized two comparative metrics: product category and usage duration. Our findings reveal notable variations in the material preferences mentioned by consumers across different product categories. The study suggests a need to re-evaluate existing standardized review criteria to better reflect consumer interests specific to each product category. Additionally, an increase in material-related terms in reviews over one month indicates the potential importance of extending the duration of product reviews to enhance the accuracy of information that reflects longer-term consumer experiences with material quality.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.2
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• pp.121-127
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• 2017

Background: There are no studies regarding 4% articaine infiltration injection into the retro-molar area for an impacted lower third molar (LITM) surgery. This study aimed to evaluate the efficacy of infiltration using 1.7 ml (single cartridge: SC) of 4% articaine versus 3.4 ml (double cartridges: DC) of 4% articaine with 1:100,000 epinephrine in LITM surgery. Method: This study involved 30 healthy patients with symmetrical LITM. The patients were assigned to receive either a DC or SC of 4% articaine with 1:100,000 epinephrine as a local anesthetic for each operation. Onset, duration, profoundness, need for additional anesthetic administration, total volume of anesthetic used, vitality of the tooth, and pain score during operation were recorded. Results: The DC of 4 % articaine had a significantly higher success rate (83.3%) than did the SC (53.3%; P<0.05). The duration of soft tissue anesthesia was longer in the DC group. The intra-operative pain was higher in the SC group with a significant (P < 0.05) requirement for a supplementary local anesthetic. Conclusion: We concluded that using DC for the infiltration injection had a higher success rate, longer duration of anesthesia, less intra-operative pain, and a lower amount of additional anesthesia than SC in the surgical removal of LITM. We recommend that a DC of 4% articaine and a 1:100,000 epinephrine infiltration in the retro-molar region can be an alternative anesthetic for LITM surgery.

• The Korean Journal of Pain
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• v.13 no.2
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• pp.182-186
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• 2000

Background: Ropivacaine is a new amide local anesthetics, having therapeutic properties similar to those of bupivacaine but less cardiovascular toxicity and motor blockade. The aim of this study was to evaluate the effects of ropivacaine used in stellate ganglion block (SGB) compared with those of lidocaine or bupivacaine. Methods: This prospective and crossover study performed in twenty patients with sudden sensory neural hearing loss. All patients received three times SGB, in the paratracheal approach using 8 ml of 1% lidocaine, 0.2% bupivacaine, and 0.2% ropivacaine respectively without any orders. Onset time and action duration of Horner's syndrome were observed after each SGB. Results: Onset time of ropivacaine was the middle of the three agents; earlier lidocaine and slower bupivacaine. Lidocaine ($3.0{\pm}1.9$ min), bupivacaine ($4.1{\pm}2.9$ min) and ropivacaine ($3.3{\pm}1.3$ min). But there were no significant differences; Action duration of Horner's syndrome of ropivacaine (223.6?105.2 min) was longer than lidocaine ($134.6{\pm}77.3$ min) and shorter than bupivacaine ($241.2{\pm}115.8$ min). There were significant differences in the action duration of each local anesthetics (P<0.05). There was no critical side effects and temporary foreign body sensation was the most common side effect. Conclusions: We conclude that ropivacaine is a good alternative in SGB instead of lidocaine or bupivacaine. Ropivacaine is a long acting local anesthetic similar to those of bupivacaine with wide margin of safety. However, optimal concentration and volume of ropivacaine in SGB should be studied.

• Archives of Plastic Surgery
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• v.47 no.5
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• pp.419-427
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• 2020

Background This study evaluated the Blossom system, an innovative self-filling, rate-controlled, pressure-responsive saline tissue expander (TE) system. We investigated the feasibility of utilizing this technology to facilitate implant-based and combined flap with implant-based breast reconstruction in comparison to conventional tissue expansion. Methods In this prospective, single-center, single-surgeon pilot study, participants underwent either implant-based breast reconstruction or a combination of autologous flap and implantbased breast reconstruction. Outcome measures included time to full expansion, complications, total expansion volume, and pain scores. Results Fourteen patients (TEs; n=22), were included in this study. The mean time to full expansion was 13.4 days (standard error of the mean [SEM], 1.3 days) in the combination group and 11.7 days (SEM, 1.4 days) in the implant group (P=0.78). The overall major complication rate was 4.5% (n=1). No statistically significant differences were found in the complication rate between the combination group and the implant group. The maximum patient-reported pain scores during the expansion process were low, but were significantly higher in the combination group (mean, 2.00±0.09) than in the implant group (mean, 0.29±0.25; P=0.005). Conclusions The reported average duration for conventional subcutaneous TE expansion is 79.4 days, but this pilot study using the Blossom system achieved an average expansion duration of less than 14 days in both groups. The Blossom system may accommodate single-stage breast reconstruction. The overall complication rate of this study was 4.5%, which is promising compared to the reported complication rates of two-stage breast reconstruction with TEs (20%-45%).

• Journal of Korean Medicine for Obesity Research
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• v.17 no.1
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• pp.10-19
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• 2017

Objectives: The aim of study was to investigate the effect of herbal medicine on obesity and to define which seasonal factor could be utilized to make an obesity treatment program more effective. Methods: Three hundred and forty-four subjects were recruited and data were analyzed for weight, body fat, muscular volume, body fat ratio, body mass index (BMI) change and treatment duration. At first, age classification was performed for the comparisons. Moreover, starting season of treatment was categorized to determine it's influence over the treatment. Results: It was found the administration of herbal medicine could diminish every analyzed fields of entire patients. Compared among age groups, there were no significant differences of all fields. However, the categorization of start season showed significant differences of weight, BMI change and treatment duration. In addition, the analysis of assumed 10% weight loss elicited patients started treatment in spring and winter should spend 12 and 13 weeks and summer would be 9.5 weeks. Conclusions: It was found herbal medicine would be effective for female obesity and expected patients could achieve 5.91 kg weight loss for 65.88 days treatment. Summer group had significant shorter treatment duration and it was presumed summer group had more concentration for achievement. Days required for assumed 10% weight loss was calculated to be 84 days in spring, 67 days in summer, 96 days in winter. Hereafter, further controlled study with more numbers of patients should be needed to determine the goal of medical treatment for obesity.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1131-1137
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• 2004

With the recent continuous expansion of subways, newly created subways tend to have lower locations and wider sections. Furthermore. since box structures and evacuating tunnels are classified into a category of mass-concrete. the thermal-stress, emitted from the inside. causes cracks to structures from the inception of constructing. In this paper, thermal-stress analysis and durability evaluation of box structure were carried out to investigate relationship between durability and parameter causing the heat of hydration. Through the examination, this paper tries to find out satisfactory solutions to regulated thermal crack and ensure the required duration period. The results of this paper showed that to control thermal crack and guarantee the required duration period it was more effective to use low-heat-portland cement and moderateheat-portland cement. As cement volume due to reduction of water-cement ratio increased, the possibility of thermal cracks occurrence increased but results of durability evaluation was different depending on evaluation method. The results showed that the appropriate water-cement ratio to control the heat of hydration and satisfy the required durability was $45\∼55\%$. And it was showed that during placement of concrete blocks ambient temperature affect the heat of hydration. thermal crack and long-term durability largely and when concrete was placed at low temperature to control thermal crack. it need to try to guarantee the required duration period. Henceforth, by studying not only internal and external conditions, such as the relative humidity and the unit weight. but also methods, to evaluate durability, in accordance with domestic situations, more reasonable design of durability should be achieved.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.2
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• pp.69-76
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• 2015

Background: There have been few studies on the effect of an elevated concentration of lidocaine hydrochloride in the surgical removal of an impacted lower third molar. This study aimed to examine the efficacy of 4% lidocaine along with 1:100,000 epinephrine compared to 2% lidocaine along with 1:100,000 epinephrine as inferior alveolar nerve block for the removal of an impacted lower third molar. Methods: This single-blind study involved 31 healthy patients (mean age: 23 y; range: 19-33 y) with symmetrically impacted lower third molars as observed on panoramic radiographs. Volunteers required 2 surgical interventions by the same surgeon with a 3-week washout period. The volunteers were assigned either 4% lidocaine with 1:100,000 epinephrine or 2% lidocaine with 1:100,000 epinephrine as local anesthetic during each operation. Results: We recorded the time of administration, need for additional anesthetic administration, total volume of anesthetic used. We found that the patient's preference for either of the 2 types of local anesthetic were significantly different (P < 0.05). However, the extent of pulpal anesthesia, surgical duration, and duration of soft tissue anesthesia were not significantly different. Conclusions: Our study suggested that inferior alveolar nerve block using 4% lidocaine HCl with 1:100,000 epinephrine as a local anesthetic was clinically more effective than that using 2% lidocaine HCl with 1:100,000 epinephrine; the surgical duration was not affected, and no clinically adverse effects were encountered.