• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.12
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• pp.1697-1703
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• 2014

In this paper, we propose an indoor RSSI (received signal strength indication)-based localization method that uses virtually overlapped visible light with an indoor LED lighting system. In our system, a photodiode (PD) measures the RSSI from LED lamps that blink in one row or column units. Subsequently, the RSSI is used to obtain the horizontal distances between the LED lamps and the receiver with the predetermined characteristics curve, R-D curve, that represents the relation between the RSSI and the horizontal distances. When the controlled LED lamps blink in one row or column units, the R-D curve at the border of the LED lamps is different because of the weak lighting, which results in the position sensing error of the receiver. The deviation of the optical power of each LED also causes the error. To solve these problems, we propose a method that overlaps the visible light through the numerical operation at the receiver side without any modification of the light source side. Our proposed method has been simulated in a room measuring $1.2{\times}1.2{\times}1.8m^3$ considering the effect of the error on the optical power of the LED. The simulation result shows that the proposed method eliminates the error condition with the R-D curve and achieves an average positioning error of 13.4 mm under the error rate 3% of the optical power.

• Geomechanics and Engineering
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• v.22 no.4
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• pp.339-348
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• 2020

The uncertain geotechnical properties of frozen soil are important evidence for the design, operation and maintenance of the frozen ground. The complex geological, environmental and physical effects can lead to the spatial variations of the frozen soil, and the uncertain mechanical properties are the key factors for the uncertain analysis of frozen soil engineering. In this study, the elastic modulus, strength and Poisson ratio of warm frozen soil were measured, and the statistical characteristics under different temperature conditions are obtained. The autocorrelation distance (ACD) and autocorrelation function (ACF) of uncertain mechanical properties are estimated by random field (RF) method. The results show that the mean elastic modulus and mean strength decrease with the increase of temperature while the mean Poisson ratio increases with the increase of temperature. The average values of the ACD for the elastic modulus, strength and Poisson ratio are 0.64m, 0.53m and 0.48m, respectively. The standard deviation of the ACD for the elastic modulus, strength and Poisson ratio are 0.03m, 0.07m and 0.03m, respectively. The ACFs of elastic modulus, strength and Poisson ratio decrease with the increase of ratio of local average distance and scale of fluctuation. The ACF of uncertain mechanical properties is different when the temperature is different. This study can improve our understanding of the spatial autocorrelation variations of uncertain geotechnical properties and provide a basis and reference for the uncertain settlement analysis of frozen soil foundation.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1467-1470
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• 2008

An upper tibial opening wedge osteotomy is an operation to cure a malalignment and a degenerate arthritis. To prevent the postoperative malalignment caused by the upper tibial opening wedge osteotomy, the research to define the relationship between a Hinge Axis Angle and a Posterior Slope Angle is needed. The effect of the relationship between the hinge axis angle and the gap angle on the posterior slope angle is studied. After 3-D Compute Tomography (CT) scanning image is reconstructed, the virtual surgery is performed by the reconstructed 3-D tibia model. It was proved that the relationship between the hinge axis angle and the gap angle were constant and the simple mathematical model could be derived. To verify the suggested mathematical model, it compared with the measured data from the virtual surgery. In conclusion, while the deviation between the data from the virtual surgery and ones of the mathematical model under the gap angle<$10^{\circ}$ was less than 1%.

• Korean Journal of Adult Nursing
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• v.28 no.1
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• pp.43-52
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• 2016

Purpose: The aim of this study was to identify demographic, clinical, physical, and psychosocial factors affecting discharge delay in lumbar spinal surgery patients who were treated according to a critical pathway. Methods: A sample of 170 patients with lumbar spinal surgery agreed to participate in the study, between April 1, 2014 and August 30, 2015. Data were analyzed by mean, standard deviation, t-test, ${\chi}^2$-test, ANCOVA, and logistic regression analysis using SPSS 22.0 program. Results: Approximately fifty-nine percent of the participants was delayed discharge. On logistic regression analysis, female gender (OR=2.63, 95% CI=1.40~4.94), age (OR=1.03, 95% CI=1.01~1.05), spondylolisthesis (OR=4.49, 95% CI=1.90~10.61), and spinal fusion operation (OR=4.14, 95% CI=1.89~9.05) were significant factors predicting discharge delay of the participants. However, discharge delay was not related with pain, physical function, depression, or family support. Conclusion: An analysis of discharge delay may assist in evaluating and revising critical pathway for optimal care. In addition, nurses need to understand the factors affecting discharge delay of the given population who were treated according to a critical pathway.

• Korean Journal of Adult Nursing
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• v.12 no.4
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• pp.546-559
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• 2000

The purpose of this study was to examine the effect of preceptorship on On the Job Training of new nurses. The research design was a retrospective survey and one group pre-post test design. The subjects were 49 entry nurses and 49 preceptors. The data were collected from Feburary 1, 1998 to December 1, 1998. One questionnair applied in this study consisted of general characteristics, the responses of new entry nurses and their preceptors and their qualities. The other questionnair consisted of job satisfaction of new entry nurses and preceptors and their competencies. The data were analyzed for frequencies, mean score, standard deviation, t-test, and ANOVA. The results of the study were as follows: 1) Preceptees's responses were that the nurses' affiliation of unit, cooperation of other nurses, and competencies of nursing skills improved after OJT applied preceptorship. 2) Preceptors's answers were that preceptorship had a positive effect on their continuing education. 3) While preceptees's job satisfaction scores were high in interaction, administration, and organization, they were low in autonomy and pay. 4) Pre-competency scores were the same as post-competency scores. 5) After preceptorship, preceptors responded that their nursing skill & communication competency increased, but their nursing administration competency decreased. 6) Finally, preceptorship's other effects were as follows: (1) Checklists for preceptee education at the nursing unit were developed separately. (2) It was proved that 'preceptor interview note' was effective on manage preceptorship. (3) We obtained duty overlap periods; medicalsurgical units-1 month, 5 ICU-2 months, operation room-3 months. (4) We prepared a preceptor program based on the study results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1351-1358
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• 2011

To approximate the threshold of the fault detection and diagnosis (FDD) system, validation of the measurements is mandatory. Naturally, the system shows uncertainties due to measuring sensors - mostly thermocouples or RTDs - and due to repeatability. The uncertainty of a thermocouple comes from natural variation or a drift of the thermocouple measurement. Considering the natural variation behaves like zero-mean white noise, its natural variation can be characterized closely by the steady-state standard deviation. However, residuals between measurements and no-fault references in FDD systems show a statistical distribution with various uncertainties. In this paper, steady-state variations of measurement residuals were investigated by utilizing built-in temperature sensors in a heat pump for the model development and the final application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1515-1521
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• 2014

This study applies simulation-based education and care for acute myocardial infarction nursing students to investigate the effect of critical thinking, problem solving, and academic achievement of a single group before and after the raw experimental design. A total of 137 subjects were arbitration period September-October 2011, enforcement and arbitration were evaluated after simulation-based training six weeks total. Data analysis was performed using SPSS Win17.0, Paired t-test, the mean and standard deviation, Pearson's correlation coefficient was used. Research results of simulation-based training program to improve critical thinking, problem solving, and academic achievement were As increase critical thinking and problem solving ability was improved. whereas, Critical thinking skills and problem solving ability was no significant difference with academic achievement. Simulation-based training program to improve the practical skills of nursing students learning was found how useful it, that there is a need to take advantage of hands-on training in a variety of cases that can be common in the field of clinical scenarios developed by. To do this, It seems to be necessary to the development and operation more varied and appropriate hands-on training method.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.6
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• pp.371-377
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• 2007

In this paper, we propose the effective operating device in the container freight station by applying the RTLS (Real Time Location System) that provides information on the container's location in real time so that the performance of the port operating system can be improved. For this, we proposed the improved dual cycling method made with the new application of two types of container's location & yard tractor's location information. we applied the RTLS to the container freight station to send the container location data to the operating system in real time; we designed the data on the Yard Tractor's location to be received via the GPS receiver and then be sent to the operating system in real time via the CDMA module. According to the analysis and evaluation of the performance of the proposed method, up to 24% of performance improvement was shown compared with the existing methods, in aspect of evaluation of work time, work time deviation and performance. Therefore, we proved that the RTLS and the GPS receiver are essential elements for efficient port operation.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.4
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• pp.29-38
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• 2003

This paper deals with an automated computer-aided process planning and die design system with which designer can determine operation sequences even after only a little experience in process planning and die design of multi former-bolt products by multi-stage former working. The approach is based on knowledge-based rules, and a process knowledge base consisting of design rules is built. Knowledge fur the system is formulated from plasticity theories, empirical results and the empirical knowledge of field experts. Programs for the system have been written in AutoLISP for AutoCAD with a personal computer. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and die design module considers several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multi former, and the availability of standard parts. It can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution and the level of the required forming loads by controlling the forming ratios. The system uses 2D geometry recognition and is integrated with the technology of process planning, die design, and CAE analysis. The standardization of die parts for multi former-bolt products requiring a cold forging process is described. The system developed makes it possible to design and manufacture multi former-bolt products more efficiently.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.86-91
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• 2008

Purpose: The performance of rhinoplasty on the patient who has already undergone unsatisfactory results or complications after augmentation rhinoplasty is a challenging surgical problem. Because the dead space is remained after removal of the foreign body and the thickness of the skin is not even, the deformity would be more conspicuous if the nose is reconstructed again with hard implant only or autogenous cartilage. In these cases, the autogenous fascia can be used to get a good result. We present our clinical experience of secondary rhinoplasty using Scarpa's fascia of lower abdomen. Methods: Thirty-two patients underwent the procedure from March of 2002 to February of 2007. Nine patients were reconstructed with Scarpa's fascia only, eighteen patients were reconstructed with silicone implant and fascia, and five patients were reconstructed with cartilage and fascia for secondary rhinoplasty. Results: There were no major complications. Most of the patients were satisfied with the results. The deviation of the silicone implant and postoperative hypertrophic scar of the donor site were seen in one case each. Postoperative absorption of fascia were seen in two cases using Scarpa's fascia only. Conclusion: Secondary rhinoplasty using Scarpa's fascia is very useful method which offers a minimized donor site scar, low complication rate, shorter operation time and patient satisfaction and prevents the alopecia caused by the harvest of temporalis fascia.