• Imaging Science in Dentistry
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• v.53 no.2
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• pp.137-144
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• 2023

Purpose: This study aimed to evaluate the anatomic circle around the impacted lower third molar to show, document, and correlate essential findings that should be included in the routine radiographic assessment protocol as clinically meaningful factors in overall case evaluation and treatment planning. Materials and Methods: Cone-beam computed tomographic images of impacted lower third molars were selected according to specific inclusion criteria. Impacted teeth were classified according to their position before assessment. The adjacent second molars were assessed for distal caries, distal bone loss, and root resorption. The fourth finding was the presence of a retromolar canal distal to the impaction. Communication with the dentist responsible for each case was done to determine whether these findings were detected or undetected by them before communication. Results: Statistically significant correlations were found between impaction position, distal bone loss, and detected distal caries associated with the adjacent second molar. The greatest percentage of undetected findings was found in the evaluation of distal bone status, followed by missed detection of the retromolar canal. Conclusion: The radiographic assessment protocol for impacted third molars should consider a step-by-step evaluation for second molars, and clinicians should be aware of the high prevalence of second molar affection in horizontal and mesioangular impactions. They also should search for the retromolar canal due to its associated clinical considerations.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.10
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• pp.947-955
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• 2010

Most oil and gas reservoirs, which have some light hydrocarbon components, show sensitive phase behavior in response to changes in the composition of the internal fluid. When evaluating and developing plans for oil and gas fields, flash calculation, PVT analysis, and saturation-property calculation are necessary for analyzing reservoir characteristics and pipeline flows. In general, the determination of saturation properties such as dew point and bubble point is considered a difficult task because of the poor convergence of the calculation methods. In this study, several new initial-value-guessing methods and root-finding methods are proposed; parametric analysis were carried out to verify the improvement in convergence. Finally, these new ideas and methods were successfully applied to the new GUI based multi-phase behavior simulator.

• Imaging Science in Dentistry
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• v.50 no.1
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• pp.53-64
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• 2020

Purpose: The aim of this study was to determine the prevalence of incidental findings(IFs) on digital dental panoramic radiographs(DPRs) of asymptomatic patients attending a general dental practice. Materials and Methods: This was a retrospective study of 6,252 consecutive digital (photostimulatable phosphor) DPRs of patients who visited a Canadian general dental practice for a complete new patient examination. The IFs were grouped into dental-related anomalies, radiopacities and radiopacities in the jaws, changes in the shape of the condyles, and other findings in the jaws, such as tonsilloliths and mucosal antral pseudocysts. Their prevalence was determined. Results: Thirty-two percent of the DPRs showed at least 1 IF. The highest prevalence was found for dental-related anomalies(29% of all DPRs), of which impacted teeth were the most prevalent finding (24% of all DPRs), followed by idiopathic osteosclerosis(6% of all DPRs). A lower prevalence was noted for tonsilloliths(3%), and the prevalence of root tips, mucosal antral pseudocysts, and anomalies in condylar shape was approximately 1% each. Conclusion: The observed prevalence of 32.1% for IFs of any type underscores the need for a dental practitioner to review the entire DPR when a patient presents for an initial dental examination (or check-up) or for dental hygiene. Only a single IF (a central giant cell granuloma) provoked alarm, as it was initially considered malignant. Similarly, impacted teeth and suspected cysts need careful evaluation upon discovery to determine how they may be optimally managed.

• The Journal of Advanced Prosthodontics
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• v.7 no.5
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• pp.380-385
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• 2015

PURPOSE. The aim of this study was to determine the frequency of significant panoramic radiographic findings and eventual treatment requirements before conventional or implant supported prosthetic treatment in asymptomatic edentulous patients. MATERIALS AND METHODS. A total of 743 asymptomatic edentulous patients were retrospectively evaluated using a digital panoramic system. We analyzed the radiographic findings, including impacted teeth, retained root fragments, foreign bodies, severe atrophy of the posterior maxillary alveolar bone, mucous retention cysts, soft tissue calcifications and radiopaque-radiolucent conditions. RESULTS. Four-hundred-eighty-seven (65.6%) patients had no radiographic finding. A total of 331 radiographic findings were detected in 256 (34%) patients. In 52.9% (n=175) of these conditions, surgical treatment was required before application of implant-supported fixed prosthesis. However, before application of conventional removable prosthesis surgical treatment was required for 6% (n=20) of these conditions. CONCLUSION. The edentulous patients who will have implant placement for implant-supported fixed prosthesis can frequently require additional surgical procedures to eliminate pathological conditions.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.175-180
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• 2006

Background: A transforaminal epidural steroid injection has been used for the treatment of radicular arm or leg pain, which has the advantage of ventral epidural spreading compared to either an interlaminar or caudal approach. However, several factors are known to affect the epidural spread pattern of contrast dye; therefore, the injected medication can not be delivered to the target site. The objective of our study was to observe any differences in the contrast flow patterns according to several factors. Methods: A total of 34 epidurographies in 29 patients, who underwent fluoroscopically guided transforaminal epidural steroid injections, were evaluated. After confirming the location of the needle tip within the anterior superior aspect of the neural foramen in the lateral view, and at the 6 o'clock position to the pedicle in the anteroposterior view, 2 ml of contrast dye was injected. The contrast flow patterns of ventral, ventral and dorsal, and dorsal epidural filling were analyzed, according to age, gender, magnetic resonance imaging finding and history of previous back surgery. Results: Ventral contrast flow occurred in 30 out of the 34 epidurographies (88%). Both ventral and dorsal contrast flow patterns were observed 13 out of 16 (81%) patients in the older age group. Also, both ventral and dorsal contrast flow patterns were observed in 16 out of 18 (88%) patients with spinal stenosis. Conclusions: Transforaminal epidural steroid injections, performed uner fluoroscopy, provide excellent nerve root filling and ventral epidural spreading. Patients with spinal stenosis or an old age have both ventral and dorsal epidural spreading patterns.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.1-14
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• 2015

The purpose of this paper is to reveal two problems in the existing inventory systems in retail market, and to suggest a Two-Bin System under Automatic Ordering System considering only base-stock. Large retailers already have a sophisticated inventory system based on an automatic ordering principle. However, why does the out-of-stock (OOS) happen in large discount stores in spite of having a good inventory system? This paper suggests two systems after finding the root causes concerning the previous question. For evaluating the performance of each system, the random 200 data set in each sample group was generated from MINITAB 16 and obeyed the Poisson distribution. The existing inventory system in retail market cannot help generating OOS due to indwelling contradiction in itself. The reasons are the ordering deadline and the relationship between ordering quantity and base stock. This paper also demonstrates that these previous studies on inventory fall into the closed loop. Also the paper shows that the performance of the replenishment policy was better than traditional methods dealing with ordering quantity and base stock.

• Journal of the Korean Home Economics Association
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• v.40 no.10
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• pp.33-48
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• 2002

The purpose of this study guides them to the needs of leave preparation and material methods for self- examination and social adaptation so that they may live their remaining time in residental care better, and that execute preliminary training to improve their qualities for healthy family lives in the future. The program of this study was tested on 8 adolescents at their high school ages selected from an orphanage in Seoul. The effect of the program was determined by the quantity evaluation with a statistical analysis(ANCOVA) and also by the quality evaluation that requires interviews. Here is the summary of the result of leave preparation program; Firstly, the leave preparation program was effective on finding self-identity, psychological welfare and personal relationship. Secondly, The program helped them recognize that their own personalities, growing-up circumstances and family in root influenced on their self-understanding and growth. Most of the subjects said they accepted these factors in an affirmative way. Thirdly, the program gave a positive effect on their views of social adaptation and family formation after leave.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.434-440
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• 2022

The ICAO (International civil aviation organization)recommended the implementation of the GANP (global air navigation plan) for strategic decision-making and air traffic management evaluation. In this study, we proposed a new method for finding the route distance from KPI (key performance indicator) 05 actual route extension presented for air traffic management evaluation. For this purpose, we collected trajectory data for one month and calculated the en-route distances using the methods presented in ICAO and the methods presented by this author. In the ICAO method, the intersection point must be estimated through the equation of a circle for radius 40 NM and the equation of a straight line for an inner and outer point close to a circle in the track data, and four flight distances are calculated to calculate the en-route distance. In the method presented in this study, two flight distances are calculated without estimating the intersection point to calculate the en-route distance. To determine the error between the two methods, we used the performance evaluation index RMSE (root mean square error) and the determination factor R² of the regression model.

• Journal of Environmental Health Sciences
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• v.48 no.3
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• pp.151-158
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• 2022

Background: Chemical emissions in the environment have rapidly increased with the accelerated industrialization taking place in recent decades. Residents of industrial complexes are concerned about the health risks posed by chemical exposure. Objectives: This study was performed to suggest modeling methods that take into account multimedia and multi-pathways in human exposure and risk assessment. Methods: The concentration of benzene emitted at industrial complexes in Daesan, South Korea and the exposure of local residents was estimated using the Caltox model. The amount of human exposure based on inhalation rate was stochastically predicted for various activity stages such as resting, normal walking, and fast walking. Results: The coefficient of determination (R²) for the CalTOX model efficiency was 0.9676 and the root-mean-square error (RMSE) was 0.0035, indicating good agreement between predictions and measurements. However, the efficiency index (EI) appeared to be a negative value at -1094.4997. This can be explained as the atmospheric concentration being calculated only from the emissions from industrial facilities in the study area. In the human exposure assessment, the higher the inhalation rate percentile value, the higher the inhalation rate and lifetime average daily dose (LADD) at each activity step. Conclusions: Prediction using the Caltox model might be appropriate for comparing with actual measurements. The LADD of females was higher ratio with an increase in inhalation rate than those of males. This finding would imply that females may be more susceptible to benzene as their inhalation rate increases.

• Journal of Preventive Medicine and Public Health
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• v.49 no.5
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• pp.308-322
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• 2016

Objectives: The objective of this study is to investigate associations between contextual characteristics and unmet healthcare needs in South Korea after accounting for individual factors. Methods: The present study used data from the 2012 Korean Community Health Survey (KCHS) of 228 902 adults residing within 253 municipal districts in South Korea. A multilevel analysis was conducted to investigate how contextual characteristics, defined by variables that describe the regional deprivation, degree of urbanity, and healthcare supply, are associated with unmet needs after controlling for individual-level variables. Results: Of the surveyed Korean adults, 12.1% reported experiencing unmet healthcare needs in the past. This figure varied with the 253 districts surveyed, ranging from 2.6% to 26.2%. A multilevel analysis found that the association between contextual characteristics and unmet needs varied according to the factors that caused the unmet needs. The degree of urbanity was associated with unmet need due to "financial burden" (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.42 to 0.66 for rural vs. metropolitan), but not unmet need due to "service not available when needed." There were no significant associations between these unmet need measures and regional deprivation. Among individual-level variables, income level showed the highest association with unmet need due to "financial burden" (OR, 5.63; 95% CI, 4.76 to 6.66), while employment status showed a strong association with unmet need due to "service not available when needed." Conclusions: Our finding suggests that different policy interventions should be considered for each at-risk population group to address the root cause of unmet healthcare needs.