• International Journal of Highway Engineering
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• v.11 no.3
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• pp.121-128
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• 2009

This study has proposed the signal operating system to use both semi-actuated signal control and pedestrian push-button as a way to make up for the problems of 3 leg intersections which are operated inefficiently in the signal operation, one of the methods of traffic operations. In case of the semi-actuated signal control, it can reduce delay inside the intersection by serving to uncongested traffic on the main road where there is not much traffic volume on the secondary road and push-button signal can reduce unnecessary waiting time it could happen to vehicles by operating it though there is no pedestrian. Quantitative analysis was tried regarding the average delay reduction per vehicle using VISSIM, microscopic simulation program regarding how much effect it has compared with the existing signal control system and semi-actuated signal control system when the above two advantages are collected. The field test was performed for one three-leg intersection of Incheon. According to respectively signal control method pedestrian traffic changed and executed a sensitivity analysis. The result which compares the average delay time per a vehicle of scenarios, the signal control method of using the pedestrian push-button system in comparison with the fixed signal control method showed to decrease effect of a minimum 3.7 second (10%), a maximum 5.8 second (16%). When the pedestrian traffic volume was 20% or less of the measurement traffic volume, The signal control method of using the pedestrian push-button system appeared to be more efficient the semi-actuated signal control with object intersection.

• School Mathematics
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• v.18 no.1
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• pp.143-157
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• 2016

North Korea had been reorganized its educational curriculum and new contexts were authored in 2013. In this study, mathematics contexts of North Korean secondary school's first grade in 2009 and 2013 were investigated. And the changes of content structure, content development, and content composition were analyzed. Results were as follows: First, with respect to the content structure, 1 chapter decreased, while lesson number was intact and 4 subunits increased. Second, with respect to the content development, considerable changes were presented. The tendencies that encouraged student and pursued a student friendly form were investigated. Third, with respect to the content composition, obvious changes were presented. It was investigated that the ratio of numbers and number operations, letters and expressions decreased nearly half. And new contents were supplemented in the areas of patterns, geometry, functions, probability and statics, equation of figures, set and statement. This changes suggests that differences between contexts of South and North Korea is narrowing compared to the past. In conclusion, the direction of North Korean mathematical education is changing for the general direction of South Korean mathematical education.

• Advances in pediatric surgery
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• v.8 no.2
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• pp.119-125
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• 2002

The aim of this study was to evaluate the posterior sagittal anorectoplasty (PSARP) as a re-do operation in patients who failed initial repair of anorectal malformation. Nine patients (4 boys and 5 girls) who had previous failed surgery for anorectal malformation underwent secondary operations through posterior sagittal approach. The main reasons of surgery were constipation (n=3) and persistent anatomical derangement in spite of previous correction surgery (n=6). In addition to constipation, the former group (n=3) had various anatomical defects, and the latter group (n=6), of course, had constipation in some degrees. Patients ranged in age from 2 to 19 years (median 3 years) with only one over the age of 6 years. The primary procedures included PSARP (n=8) and anoplasty (n=1). The rectum was mobilized from surrounding structures through posterior sagittal approach and anatomical defects were corrected. The rectum underwent reconstruction, which involved relocation of the rectum and anus within the limits of the intact muscle complex. Patients underwent follow-up for periods ranging from 6 to 77 months (mean 37 months) after surgery. Anatomical corrections of all the defects were successfully fulfilled in 9 patients. All the patients were satisfied with the functional results after redo-PSARP compared with the preoperative defecatory function. This study suggests that (1) some of the patients with troublesome constipation may have anatomical defects, prominent or hidden, (2) surgeons should suspect the possibility of anatomical defect as the cause of incontinence and (3) preoperative thorough investigation to reveal the anatomical defects should be included in estimating patients with severe incontinence after previous surgery and planning the correction for failed previous surgery as well.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.117-144
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• 2013

The MOLIT is also establishing the flight safety standards for UAV within the current Aviation Law. Accordingly the required flight criteria includes operator location, mission operation limit, equipment, etc. which are the principle and standard applied based on the airspace use for UAV. Also, general flight rules, visual flight rules, instrument flight rules are required to be applied to the actual flight. Besides, an appliance regulation needs to be arranged regarding two-way communication, ATC and communication issue, airspace and area in-flight between UAS(Unmanned Aircraft System) users. An operation of the UAV in the air significantly requires the guarantee of the aircraft's capacity, and also the standardized flight criteria. A safe and smooth use is ensured only if this criteria is applied and understood by the entire airspace users. For the purpose, a standardized military UAV flight operations criteria and a law complementary scheme.

• Archives of Plastic Surgery
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• v.37 no.6
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• pp.823-826
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• 2010

Purpose: Meningomyelocele is the most common type of neural tube defect disease. Early surgical treatment is recommended to prevent central nervous system infection. Several reconstruction methods were reported previously regarding surgical wound defect closure following meningomyelocele excision. In this article, we report two successful patients using the bilateral fasciocutaneous sliding V-Y advancement flap as a covering for meningomyelocele defects. Methods: Two patients with meningomyelocele were evaluated. Both patients were male and received their operations on the 1st and 4th day of life. After neurosurgeons completed their part of the operation, the V-Y advancement flap was used to close the defect. Initially a bilateral V-shape incision design was made on the skin such that the base of the V-flap measures identical to the size of the wound defect. An incision was made down to the fascia in order to allow the V-flaps to slide into the defect. Subfascial dissection was performed up to 1/3 to 1/4 the length of the V-flap from the wound while minimizing injury to the perforating vessels. Results: Both patients were treated successfully and there was no evidence of complication in 2 months follow up. Conclusion: Several reconstruction methods such as local flaps, skin graft and myocutaneous flaps were reported regarding meningomyelocele surgical wound defect closure. Bilateral fasciocutaneous sliding V-Y advancement flap is an easy method without involving the underlying muscles or a secondary skin graft in a short operation time. Therefore we recommend this treatment option for reconstruction of the wound defect following meningomyelocele excision.

• Proceedings of the Korean Society of Rheology Conference
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• 2006.06a
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• pp.81-84
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• 2006

Slot coating process, in continuous and patch modes, has been applied for the many precise coating products, e.g., flat panel displays and second batteries. However, manufacturing uniform coating products is not a trivial task at high-speed operations because various flow instabilities or defects such as leaking, bubbles, ribbing, and rivulets are frequently observed in this process. It is no wonder, therefore, that many efforts to understand the various aspects of dynamics and coating windows of this process have been made both in academia and industry. In this study, as the first topic, flow dynamics within the coating bead in slot coating process has been investigated using the one-dimensional viscocapillary model by lubrication approximation and two-dimensional model by Flow-3D software. Especially, operability windows in both 1D and 2D cases with various slot die lip designs have been successfully portrayed. Also, effects of process conditions like viscosity and coating gap size on slot coating window have been analyzed. Also, some experiments to find minimum coating thickness and coating windows have been conducted using slot die coater implemented with flow visualization device, corroborating the numerical results. As the second topic, flow dynamics of both Newtonian and Non-Newtonian fluids in patch or pattern slot coating process, which is employed in manufacturing IT products such as secondary batteries, has been investigated for the purpose of optimal process designs. As a matter of fact, the flow control in this system is more difficult than in continuous case because od its transient or time-dependent nature. The internal die and die lip designs for patterned uniform coating products have been obtained by controlling flow behaviors of coating liquids issuing from slot. Numerical simulations have been performed using Fluent and Flow-3D packages. Flow behavior and pressure distribution inside the slot die has been compared with various die internal shapes and geometries. In the coating bead region, efforts to reduce irregular coating defects in head and tail parts of one patterned coating unit have been tried by changing die lip shapes. It has been concluded that optimal die internal design gas been developed, guaranteeing uniform velocity distribution of both Newtonian and shear thinning fluids at the die exit. And also optimal die lip design has been established, providing the longer uniform coating layer thickness within one coating unit.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.19-27
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• 2023

As the secondary battery market expands, the process of producing laterite ore using the rotary kiln and electric furnace method is expanding worldwide. As ESG management expands, the management of air pollutants such as nitrogen oxides in exhaust gases is strengthened. The rotary kiln, one of the main facilities of the pyrometallurgy process, is a facility for drying and preliminary reduction of ore, and it generate nitrogen oxides, thus prediction of nitrogen oxide is important. In this study, LSTM for regression prediction and LightGBM for classification prediction were used to predict and then model optimization was performed using AutoML. When applying LSTM, the predicted value after 5 minutes was 0.86, MAE 5.13ppm, and after 40 minutes, the predicted value was 0.38 and MAE 10.84ppm. As a result of applying LightGBM for classification prediction, the test accuracy rose from 0.75 after 5 minutes to 0.61 after 40 minutes, to a level that can be used for actual operation, and as a result of model optimization through AutoML, the accuracy of the prediction after 5 minutes improved from 0.75 to 0.80 and from 0.61 to 0.70. Through this study, nitrogen oxide prediction values can be applied to actual operations to contribute to compliance with air pollutant emission regulations and ESG management.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.2
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• pp.169-190
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• 2024

The purpose of this study is to design an effective innovation model for communication-centered public services, based on the case of Korea Midland Power Co., Ltd (KOMIPO). This study analyzed customer and employee participation activities at KOMIPO, focusing on communication activities to derive the best practices. The study comprised of the following stages: (1) Preparation stage to assess the current situation and promote change management; (2) Problem-solving stage for improving public services; (3) Problem-solving stage for improving work processes; (4) Problem-solving stage for strengthening collaboration, and (5) Design stage for an innovation model. Based on the results of this study, an innovation model was developed for public services by applying the double-diamond design process. The proposed model presents a process structure, which is derived through an iterative process of primary divergence (discovery) and convergence (definition), and secondary divergence (development) and convergence (delivery). This study also proposed the possibility of applying the Idea-Power-Plant activities of KOMIPO's best practices to the proposed model. While this study proposed an innovation model for communication-centered public services through the analysis of a specific public company, the results of the study provide broad insights for effective operations management through efficient communication based on the participation of customers and employees in public institutions.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.13 no.2
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• pp.173-179
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• 2002

Background and Objectives : Intracordal cysts may occur secondary to voice abuse and overuse or may be secondary to a remnant of epithelium trapped within the lamina propria. They nay occur spontaneously or may be associated with poor vocal hygiene. As the cyst enlarges it can start to significantly affect the vibratory region of the vocal fold. Recently, with the advancement of the microsurgical technique and the laryngeal stroboscopy, correct diagnosis of intracordal cyst have been increased. The aims of this study is to review the important clinical characteristics of the intracordal cyst. Materials and Method : In the present study, 121 cases of the intracordal cyst were treated by the microsurgical technique. These lesions were diagnosed before the operation with indirect laryngoscopy, laryngeal endoscopy, laryngeal stroboscopy and confirmed with the findings observed during operations and the results of the biopsies. Results : The intracordal cysts were 121 cases in the 2595 patients who underwent laryngeal micorosurgery(4.7%). Ductal cyst were 88 cases and epidermoid cyst were 33 cases. The lesions are more frequent in women and anterior third of true vocal cord is more frequently involved site. With the indirect laryngoscopic examination, the ductal cysts are more frequently misdiagnosed as other diseases of the vocal cord such as vocal polyps or nodules. The degree of postoperative voice satisfaction is similar to that of vocal polyps. Conclusion : Intracordal cysts are very similar to the other mucosal disorders of the vocal cord and it may be misdiagnosed as vocal polyps or nodules, frequently. Therefore careful preoperative examinations for the vocal cord lesions with stroboscopy and other endoscopic instruments are important part of the correct diagnosis. An ideal treatment is enucleation of the cysts without upture of the cystic wall or injury of the lamina propria.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.1
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• pp.47-51
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• 2009

Background and Objectives: Intracordal cysts may occur secondary to voice abuse and overuse or may be secondary to a remnant of epithelium trapped within the lamina propria. They may occur spontaneously or may be associated with poor vocal hygiene. As the cyst enlarges it can start to significantly affect the vibratory region of the vocal fold. With the advancement of the microsurgical technique and the laryngeal stroboscopy, correct diagnosis of intracordal cyst have been increased. The aims of this study is to review the important clinical characteristics of the intracordal cyst. Materials and Methods: In the present study, 212 cases of the intracordal cysts were treated by the microsurgical technique. These lesions were diagnosed before the operation with indirect laryngoscopy, laryngeal endoscopy, laryngeal stroboscopy and confirmed with the findings observed during operations and the results of the biopsies. Results : The intracordal cysts were 212 cases in the 4,20 I patients who underwent laryngeal microsurgery (5.04%). Ductal cysts were 156 cases and epidermoid cysts were 56 cases. The lesions are more frequent in women and anterior third of true vocal cord is more frequently involved site. With the preoperative laryngoscopic examination, the intracordal cysts were mostly misdiagnosed as other disease of the vocal cord such as vocal polyps or nodules. And main cause of intracordal cysts was thought of vocal abuse. From view of the surgical approach, Ductal cysts was difficult to remove completely than epidermoid cyst without cystic wall rupture. Conclusion : Intracordal cysts are very similar to the other mucosal disorders of the vocal cord and it may be misdiagnosed as vocal polyps or nodules, frequently. Therefore careful preoperative examinations for the vocal cord lesions with stroboscopy and other endoscopic instruments are important part of the correct diagnosis. An ideal treatment is enucleation of the cysts without rupture of the cystic wall or injury of the lamina propria. And marsupialization is meaningful to ductal cyst that cannot be enucleated completely.