• Journal of the Korea Society of Computer and Information
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• v.28 no.8
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• pp.11-19
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• 2023

In this paper, it is confirmed that the metrics used to evaluate image quality can be applied to low-light images. Due to the nature of low-illumination images, factors related to light create various noise patterns, and the smaller the amount of light, the more severe the noise. Therefore, in situations where it is difficult to obtain a clean image without noise, the quality of a low-illuminance image from which noise has been removed is often judged by the human eye. In this paper, noise in low-illuminance images for which ground truth cannot be obtained is removed using Noise2Noise, and spatial resolution and radial resolution are evaluated using ISO 12233 charts and colorchecker as metrics such as MTF and SNR. It can be shown that the quality of the low-illuminance image, which has been evaluated mainly for qualitative evaluation, can also be evaluated quantitatively.

• Geomechanics and Engineering
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• v.31 no.4
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• pp.375-384
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• 2022

The variation of the undrained shear strength (c_u) is an important consideration for assessing slope stability in engineering practice. Previous studies focused on the three-dimensional (3D) stability of slopes in normally consolidated clays generally assume the undrained shear strength increases linearly with depth but does not vary in the horizontal direction. To assess the 3D stability of slopes with spatially varying undrained shear strength, the kinematic approach of limit analysis was adopted to obtain the upper bound solution to the stability number based on a modified failure mechanism. Three types failure mechanism: the toe failure, face failure and below-toe failure were considered. A serious of charts was then presented to illustrate the effect of key parameters on the slope stability and failure geometry. It was found that the stability and failure geometry of slopes are significantly influenced by the gradient of c_u in the depth direction. The influence of c_u profile inclination on the slope stability was found to be pronounced when the increasing gradient of c_u in the depth direction is large. Slopes with larger width-to-height ratio B/H are more sensitive to the variation of c_u profile inclination.

• Journal of Korean Academy of Nursing
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• v.25 no.4
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• pp.709-728
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• 1995

The job related activities of sixty nine nurses, working in the emergency rooms of three university hospitals, were analyzed for six days according to preestablished checklist of nursing activities ; the frequency of these activities and the amount of time spent in each specific nursing activity. The established checklist was monitored every five minutes for the duration of the duty autu, thus producing 414 items of data. The data were not gathered on consecutive days but over the period of one month from May 6, 1994 to June 5, 1994. The following conclusions are derived from analysis of the data : 1. Twelve categories of nursing activities were obtained : The primary activity was communication related to the patient and all information pertaining to the patient. Other activities included maintaining the patient's record, observation and assessment of the patient, cooperation with other medical personnel, management of equipment and drugs, procedure and treatment, specimen collection, consultation and education for the patient, including drug management and personal hygiene and any other relevant education to the patient's condition. 2. The average frequency of categorized nursing activity can be classified as follows : communication related to patient was the highest at 17.6 times. The next was maintaining the patient's record at 17.3 times. The observation and assessment occurred 16.9 times. Consultation and education for patients and family, 8 times, medication, 5.7 times, and procedures and treatments, 6 times. 3. The average time required for each activity was as follows : 230.1 minutes (or maintaining the patient's record, 204.9 minutes for communication related to the patient, 199.2 minutes for observation and assessment, 71.2 minutes for medication, 66 minutes for consultation and education of the patient and family, and 51.8 minutes for procedures and treatment. 4. The most demanding nursing activity in the emergency room for the nurse was answering questions from the patient's family, maintaining communication between the medical staff, maintaining and reviewing the patient's charts, writing prescriptions and monitoring 1. V. infusion rates. 5. The most time consuming nursing activities for the emergency room nurse include maintaining and following the patient's charts, communication between the medical staff, answering questions from the patient's family, observation of the patient and relaying all of the appropriate patient information to the incoming nurses during a shift change. 6. The F-test was administered to measure the required time for the categorized nursing activities according to day, evening, and night-shift nurses. There were significant differences (p<.05) in specimen collection, observation and assessment, cooperation between medical staffs, personal hygiene, communication related to patient, education and re-search. Posterior multiple comparison test showed that specimen collection, cooperation between medical staffs and personal hygiene were mostly done by the evening-shift nurses. Also most observations and assessments were done by the night-shift nurses. Education and communication to patients were done by day-shift nurses. Thus there were significant difference between shifts for the main nursing activities. So there should considev a reallocation of the duty of nurses on each shift. 7. The F-test also indicated that there wes a similarity in time duration for procedures and treatments and for cooperation between medical staff and nurses in all three hospitals. However, the remaining categories of nursing activities also showed a significant difference between the three hospitals. This indicated that there were differences in each emergency room that influence time for each categorized nursing activities and this should be given more consideration. Recommendations : 1. A seasonal difference should be considered in the activities of nurses in the emergency room and a comparative analysis should be carried out to deter-mine seasonal differentiation. 2. A study on more objectively measurable nursing activities should be administered as well as one determining the subjective responds towards nursing activities in the emergency room.

• Earthquakes and Structures
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• v.24 no.6
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• pp.455-475
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• 2023

The present study investigates the non-linear soil-pile interaction using three-dimensional (3D) non-linear finite element models. The numerical models were validated by using the results of extensive pile load and shaking table tests. The pile performance in liquefiable and non-liquefiable soil has been studied by analyzing the liquefaction ratio, pile lateral displacement (LD), pile bending moment (BM), and frictional resistance (FR) results. The pile models have been developed for the different ground conditions. The study reveals that the results obtained during the pile load test and shaking cycles have good agreement with the predicted pile and soil response. The soil density, peak ground acceleration (PGA), slenderness ratio (L/D), and soil condition (i.e., dry and saturated) are considered during modeling. Four ground motions are used for the non-linear time history analyses. Consequently, design charts are proposed depended on the analysis results to be used for design practice. Eleven models have been used to validate the capability of these charts to capture the soil-pile response under different seismic intensities. The results of the present study demonstrate that L/D ratio slightly affects the lateral displacement when compared with other parameters. Also, it has been observed that the increasing in PGA and decreasing L/D decreases the excess pore water pressure ratio; i.e., increasing PGA from 0.1 g to 0.82 g of loose sand model, decrease the liquefaction ratio by about 50%, and increasing L/D from 15 to 75 of the similar models (under Kobe earthquake), increase this ratio by about 30%. This study reveals that the lateral displacement increases nonlinearly under both dry and saturated conditions as the PGA increases. Similarly, it is observed that the BM increases under both dry and saturated states as the L/D ratio increases. Regarding the acceleration histories, the pile BM was reduced by reducing the acceleration intensity. Hence, the pile BM decreased to about 31% when the applied ground motion switched from Kobe (PGA=0.82 g) to Ali Algharbi (PGA=0.10 g). This study reveals that the soil conditions affect the relationship pattern between the FR and the PGA. Also, this research could be helpful in understanding the threat of earthquakes in different ground characteristics.

• Journal of Korean Neurosurgical Society
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• v.59 no.2
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• pp.117-121
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• 2016

Objective : Hemorrhagic moyamoya disease (hMMD) is associated with a poor clinical course. Furthermore, poorer clinical outcomes occur in cases of recurrent bleeding. However, the effect of hemodynamic insufficiency on rebleeding risk has not been investigated yet. This study evaluated the prognostic implications of the perfusion status during the clinical course of adult hMMD. Methods : This retrospective study enrolled 52 adult hMMD patients between April 1995 and October 2010 from a single institute. Demographic data, clinical and radiologic characteristics, including hemodynamic status using single photon emission computed tomography (SPECT), and follow up data were obtained via a retrospective review of medical charts and imaging. Statistical analyses were performed to explore potential prognostic factors. Results : Hemodynamic abnormality was identified in 44 (84.6%) patients. Subsequent revascularization surgery was performed in 22 (42.3%) patients. During a 58-month (median, range 3-160) follow-up assessment period, 17 showed subsequent stroke (hemorrhagic n=12, ischemic n=5, Actuarial stroke rate $5.8{\pm}1.4%/year$). Recurrent hemorrhage was associated with decreased basal perfusion (HR 19.872; 95% CI=1.196-294.117) and omission of revascularization (10.218; 95%; CI=1.532-68.136). Conclusion : Decreased basal perfusion seems to be associated with recurrent bleeding. Revascularization might prevent recurrent stroke in hMMD by rectifying the perfusion abnormality. A larger-sized, controlled study is required to address this issue.

• Journal of The Korean Association For Science Education
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• v.17 no.3
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• pp.313-321
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• 1997

The purpose of this study was to investigate the instructional effect of a four-stage problem solving approach visually emphasizing the molecular level of matter upon students' conceptions and problem solving ability. On the basis of the research results regarding molecular representation in learning chemistry, problem-solving instruction, and the effect of visual materials, the instructional strategy was developed while considering Korean educational situations. The treatment and control groups (2 classes) were selected from a girls' high school in Seoul and taught about stoichiometry, gas, liquid, solid, and solution for 13 weeks. For the treatment group, 52 charts were supplied in order to emphasize the molecular level of matter and/or 4 stage problem solving strategy-understanding, planning, solving, and reviewing. For the control group, traditional instruction was used. Before the instructions, the Group Assessment of Logical Thinking and the Spatial Ability Test were administered, and their scores were used as covariate and blocking variable, respectively. After the instructions, students' conceptions and problem solving ability were measured by the Chemistry Conceptions Test (CCT) and the Chemistry Problem Solving Ability Test (CPSAT), respectively. The results indicated that the CCT scores of the treatment group were significantly higher than those of the control group. The students in the treatment group also exhibited less misconceptions than those in the control group. However, there was not significant difference for the CPSAT scores. No interaction with students' spatial ability was found for both students' conceptions and problem solving ability. Educational implications are discussed.

• Journal of Korean Neurosurgical Society
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• v.57 no.2
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• pp.100-107
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• 2015

Objective : To report a minimally invasive treatment option using percutaneous pedicle screw fixation with adjuvant treatment for metastatic thoraco-lumbar and lumbar spinal tumors. Methods : This is a retrospective study of charts of patients with spinal metastases. All were older than 18 years of age and were considered to have more than 3 months of life expectancy. The patients had single or two level lesions, and compression fracture or impending fracture. Exclusion criterion was metastasis showing severe epidural compression with definite neurological symptoms. Usually spinal segments from one level above to below pathology were stabilized. Visual analog scale (VAS) score for pain assessment and Frankel scale for neurological deficit were used, while pre- and post-operative performance status was evaluated using the Eastern Cooperative Oncology Group (ECOG). Results : Twelve patients (nine men, three women; median age 54.29 years) underwent surgery. All patients presented with back pain with/without radicular pain. There were no early complications and perioperative mortalities. Following surgery, a significant difference between average pre- and post-operative VAS scores was found (p=0.003). Overall, 91.8% of patients (11/12) experienced improvement in their ECOG score post-operatively. The mean ambulation time was 196.9 days [95% confidence interval (CI), 86.2-307.6 days; median, 97 days]. During follow-up, nine patients died and the mean overall survival time in enrolled twelve patients was 249.9 days (95% CI, 145.3-354.4 days; median, 176 days). Conclusion : Minimally invasive treatment using percutaneous pedicle screw fixation with adjuvant treatment is a good alternative treatment option for potential instability of the thoraco-lumbar and lumbar spinal metastasis.

• Quality Improvement in Health Care
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• v.2 no.2
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• pp.32-45
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• 1996

Background : A critical path defines an optimal sequencing and timing of interventions by physicians, nurses, and other staff for a particular diagnosis or procedure, designed to better utilize resources, maximize quality of care, and minimize delays. It can be thought of as a visualization of the patient care process. In this study, a review of appendectomy patient records was undertaken to identify a critical path for the management of this treatment. Methods: For this study, records of patients under 15 or over 65 years of age were excluded ; cases where the patient was pregnant, or where complications developed were also excluded. The remaining 21 cases were divided into two categories according to the indication for appendectomy : for acute appendicitis, and for perforated appendix or drainage of periappendical abscess. The time frame for the review was from patient examination immediately prior to operation, through discharge. The study team was composed of a surgeon, research head nurse, education head nurse, surgical part head nurse, and medical recorder. Following their review of the 21 charts, the team determined an appropriate progression and schedule for an appendectomy. Result : Through the chart and literature review, the following aspects of the care process were identified as typical and tracked : monitoring/assessment, treatment, lines/drains, medication, activity, diet, tests and patient education. Conclusion : From this study, the design team determined two separate critical paths : one for appendectomy only, and one for appendectomy plus drainage. Next, these paths must be validated and fine-tuned through clinical implementation. In addition, a comparison of our design with the critical paths determined at other hospitals would be extremely valuable for advancing research in this area. Lastly, the critical path approach to improving patient care and maximizing hospital resources should be applied to other procedures.

• The Journal of Advanced Prosthodontics
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• v.5 no.3
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• pp.351-358
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• 2013

PURPOSE. This retrospective study analyzed the distribution of the dental implants with regards to age and gender of the patients and type of indication for the implant therapy, as well as the location, dimension and type of the implants. MATERIALS AND METHODS. The data of demographics (age and gender), type of indication for implant therapy, anatomical location, dimensions (length and diameter) and type (bone and tissue level) of 1616 implants were recorded from patient charts between January 2000 and January 2010. Descriptive statistics were analyzed using a chi-squared test for demographic parameters, type of indication, tooth position, anatomical location, implant dimensions and type (${\alpha}$=.05). RESULTS. The patient pool comprised of 350 women and 266 men, with a mean age of $52.12{\pm}13.79$ years. The difference in n% of the implants of the age groups was statistically significant between the types of indications. The difference in the position of the implants was statistically significant between the n% of the implants of all age groups. Gender did not significantly vary, except that the diameter of the implants was significantly higher for the standard diameter implants in males. The difference between the implant positions was statistically significant when considered according to indication. The relationship between implant length and anatomical location was statistically significant. CONCLUSION. The indication for dental implant use is age dependent and the type and size of the implant seems to be strongly related to the location of the implant.

• Journal of The Korean Dental Society of Anesthesiology
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• v.2 no.2 s.3
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• pp.101-106
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• 2002

Background: The management of the behavior of handicapped children when providing required dental care is often a problem, whether in the dental office or in a hospital setting. Because of the high incidence of poor cooperation, many of these patients are scheduled for dental care under general anesthesia with preoperative medical assessment. The purpose of this study was to carry out a clinico-statistical survey on dental treatment for handicapped children under general anesthesia. Methods: After approval from the institutional review board, the medical records of 64 handicapped children between 1997 and 2002 were reviewed to determine the patient profiles, anesthesia management, and complications. The charts of these patients, who underwent dental examination, scaling and prophylaxis, and restoration and extraction of teeth under general anesthesia, were reviewed. Results: The mean age was 12.8 years old, and males (53%) predominated females (47%). Twenty-four patients had mental retardation, twelve had autism, six had cerebral palsy, 4 had behavior disorder, others had heart disease, convulsive disorder, etc. Sixty-two had intravenous thiopental with neuromuscular blocker, 2 had intravenous ketamine induction. Nasotracheal intubation was uneventful in 55 patients, nine had orotracheal intubation because of difficult visualization of the larynx. Twenty-one patients experienced postoperative complications in the recovery room, including epistaxis, nasal obstruction, vomiting, airway obstruction, respiratory depression. Conclusions: General anesthesia is a very effective way of completing the dental treatments for disabled children. We emphasize the need to train anesthesiologists in the care of disabled patients.