• Journal of the Korean Society of Physical Medicine
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• v.17 no.3
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• pp.79-86
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• 2022

PURPOSE: By virtue of its location, the iliopsoas muscle has the potential to affect the function of the diaphragm. Therefore, the purpose of this study was to investigate the effects of passive stretching of the iliopsoas muscles on pulmonary function. METHODS: Twenty male university students participated in this study. Subjects with low back pain, negative results on the modified Thomas test, and chest breathing patterns not directly related to the function of the iliopsoas muscles were excluded from this study. A digital pulmonary function measuring device (Pony FX, COSMED Inc, Italy) was used to test pulmonary function. The test was performed three times: the first test before passive stretching, the second test 10 minutes after the first test, and the third after passive stretching. Passive stretching was performed 5 times for each of the left and right iliopsoas muscles. Passive stretching was carried out for 20 seconds followed by a 10-second break. The SPSSWIN (ver. 27.0) statistics program was used for data analysis, and the significance level was α =.05. RESULTS: Among slow vital capacity (SVC) parameters, tidal volume (VT), inspiratory reserve volume (IRV), inspiratory capacity (IC) and vital capacity (VC) improved significantly after passive stretching. Also, among the maximal effort vital capacity (MEVC) parameters, forced vital capacity(FVC) and forced expiratory volume in one second(FEV1) improved significantly after passive stretching. CONCLUSION: The results showed that among the various pulmonary function parameters measured, passive stretching of the iliopsoas muscles can improve the SVC and MEVC. Therefore, passive stretching of the iliopsoas muscles may be considered for use as a treatment method to improve pulmonary function.

• Korean Journal of Applied Biomechanics
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• v.33 no.1
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• pp.1-9
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• 2023

Objective: This study identifies the difference among the heights of a chair's backrest (High, Mid, No), the biomechanical changes chair users undergo over time, and the variables that can measure musculoskeletal disorders, eventually providing information on the appropriate type of backrest. Method: Eleven healthy subjects in their 20s and 30s who had no experience with musculoskeletal disorders or surgical operations within the last 6 months participated in this study. Computer typing tasks were randomly designated and performed according to the type of chair backrest, and evaluation was performed for Flexion-Relaxation Ratio (FRR) analysis after the computer typing tasks. This study used eight infrared cameras (sampling rate: 100 Hz) and nine-channel electromyography (sampling rate: 1,000 Hz). ANOVA with repeated measures was conducted to verify the results, with the statistical significance level being α = .05. Results: Although there was no significant difference in craniovertebral angle (CVA), this study showed time and interaction effects depending on the height of the backrest (p<.05). When working without the backrest, the head-spine angle was lower compared to the chairs with backrest, based on the computer work. As for the head angle, the higher the back of the chair was, the less the head flexion and the body angle became, whereas the body flexion became less when there was a backrest. In addition, the body flexion increased over time in all types of backrests (p<.05). The muscle activity of the upper body tended to be high in the high backrest chair. On the other hand, a lower muscle activity was found with a low backrest. Conclusion: These results show that a chair is more ergonomic when the body angle is correctly set without bending and when it is supported by a low backrest. Accordingly, this study determines that the backrest affects shoulder and neck musculoskeletal disorders during typing and that medium-height backrest chairs can help prevent musculoskeletal disorders, contrary to the expectation that high-backrest chairs are preferable.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.158-160
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• 2022

Many office workers spend a lot of time performing repetitive office tasks in inefficient ways. We developed a user-friendly chatbot system based on Kakaotalk to automate repetitive tasks and used the chatbot in the real workplace. In the process of operating the chatbot, if several people use the chatbot at the same time, the server was down or could not respond. To address these issues, we performed code migration of programs used by chatbot back-end servers and tried several ways to improve server performance such as database redesign and load balancing. To determine how much each method affects performance improvement, we measured total request per second and average latency. After that, we proposed ways to improve the problems of using the chatbot in the work environment.

• Journal of the Korean Geotechnical Society
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• v.23 no.1
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• pp.5-11
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• 2007

Micropiles have been used for underpinning or rehabilitation of existing foundations, and direct structural support system as well. However, relatively few studies have been done on the load-transfer mechanism of micropile systems in Korea. In addition to that, only the limited information is available for estimating the side friction values on micropiles installed in weathered soils. In this study, a full-scale test on an instrumented micropile is performed in order to establish the load-transfer curves based on a hyperbolic function. Then, an empirically derived equation that correlates the load-transfer curve of micropiles with the N values from field standard penetration tests is proposed. The results from all procedures are presented in this paper. Finally, back analysis using a finite difference method and the published field data are adopted for examination of a developed skin friction equation of micropile in weathered soils respectively.

• Journal of the Society of Disaster Information
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• v.20 no.3
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• pp.663-671
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• 2024

Purpose: The purpose of this study is to examine the risks and criminal progress of pig murder fraud crimes in the absence of related research and statistics amid a surge in pig murder fraud damage in Korea, and to approach the methods, problems, and countermeasures that can be prevented in Korea through foreign cases. Method: In order to classify the types of pig murder fraud crimes, the progress was analyzed through related reports and statistics, and various damage cases. Result: The crime of pig murder fraud can be seen as an organized crime that organically combines simple romance scams, investment fraud, and human trafficking. In the case of victims, unlike simple fraud, psychological problems such as suicide impulse and panic disorder were found, and in the case of cryptocurrency acquired through fraud, a path was found to flow back into the criminal organization through money laundering. Conclusion: In the case of pig murder fraud crimes that have been detected as a danger worldwide, the scale will be even wider. Therefore, various institutional supplements and policies should be prepared through crime type analysis in Korea for crime prevention and countermeasures.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.386-393
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• 2017

Onion downy mildew, caused by Peronospora destructor, is a major disease in onion cultivation areas in Korea. The causal fungi were collected and analyzed based on sequence similarity and molecular phylogenetic relationships of multi-gene sequences, including the internal transcribed spacer (ITS) region. All isolates from Changnyeong-gun, Hamyang-gun, and Hapcheon-gun in Gyeongnam province, and Muan-gun, Haenam-gun, and Sinan-gun in Jeonnam province were identical in the four types of gene sequences, indicating they were genetically the same strains. In this study, a PCR method was developed based on the ITS gene sequences to amplify the specific DNA fragment for P. destructor only. The detection limit of was total genomic DNA of the P. destructor and the plant $0.7ng/{\mu}L$. Therefore, the developed PCR method could be used to detect P. destructor effectively from symptomless onion leaves.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6019-6023
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• 2013

Lung cancer, one of the leading causes of cancer-related deaths, usually appears as solitary pulmonary nodules (SPNs) which are hard to diagnose using the naked eye. In this paper, curvelet-based textural features and clinical parameters are used with three prediction models [a multilevel model, a least absolute shrinkage and selection operator (LASSO) regression method, and a support vector machine (SVM)] to improve the diagnosis of benign and malignant SPNs. Dimensionality reduction of the original curvelet-based textural features was achieved using principal component analysis. In addition, non-conditional logistical regression was used to find clinical predictors among demographic parameters and morphological features. The results showed that, combined with 11 clinical predictors, the accuracy rates using 12 principal components were higher than those using the original curvelet-based textural features. To evaluate the models, 10-fold cross validation and back substitution were applied. The results obtained, respectively, were 0.8549 and 0.9221 for the LASSO method, 0.9443 and 0.9831 for SVM, and 0.8722 and 0.9722 for the multilevel model. All in all, it was found that using curvelet-based textural features after dimensionality reduction and using clinical predictors, the highest accuracy rate was achieved with SVM. The method may be used as an auxiliary tool to differentiate between benign and malignant SPNs in CT images.

• Journal of the Korean Magnetics Society
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• v.25 no.3
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• pp.92-100
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• 2015

Electric Vehicle (EV) can be categorized by the driving method into in-wheel and in-line types. In-wheel type EV does not have transmission shaft, differential gear and other parts that are used in conventional cars, which simplifies and lightens the structure resulting in higher efficiency. In this paper, design method for in-wheel motor for automobiles using Parameter Map is proposed, and motor with continuous power of 5 kW is designed, built and its performance is verified. To decide the capacity of the in-wheel motor that meets the automobile's requirement, Vehicle Dynamic Simulation considering the total mass of vehicle, gear efficiency, effective radius of tire, slope ratio and others is performed. Through this step, the motor's capacity is decided and initial design to determine the motor shape and size is performed. Next, the motor parameters that meet the requirement is determined using parametric design that uses parametric map. After the motor parameters are decided using parametric map, optimal design to improve THD of back EMF, cogging torque, torque ripple and other factors is performed. The final design was built, and performance analysis and verification of the proposed method is conducted by performing load test.

• The Mathematical Education
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• v.42 no.2
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• pp.203-218
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• 2003

The purpose of this study is to see what the essential characteristics are in teaching probability and statistics among various mathematical fields. we also tried to connect the study of probability and statistics education with what is needed for a science be synthetic to have its own identity as a unique research field. Since we searched for the future direction of the pedagogic study in the probability and statistics we first selected papers on probability and statistics published in (Series A), the Journal of Korea Society of Mathematical Education, and establish the following research questions. What kinds of characteristics can be found when papers on probability and statistics published in (Series A) are classified into low categories; contents of probability and statistics education, research method of the mathematics education, methods of teaming and teaching, and finally measurements and evaluation\ulcorner We classified papers into two kinds. One is related to the educational contents, consisting of the methods of learning and teaching, and of the measurement and evaluation. The other is reined to the methods of research, which is not a part of the educational curriculum but is essential for establishing the identity of mathematics education. According to the periods, papers on the curricular contents in 1960s were influenced by the New Mathematics, and papers on the curricular contents in 1980s were influenced by 'back to basic'. In 1990s, papers on methods of learning and teaching, and measurement md evaluation were increasing in number. Besides, (series A) from the Journal of Korea Society of Mathematical Education covers contents, methods of Loaming and teaching, and measurement and evaluation. And when I examined the papers on the contents of textbook of a junior high school related to the probability and statistics education and on methods of learning and teaching, 1 found that those papers occupy 1.84% in . When it comes to the methods of loaming and teaching, most of studies in (series A) are about application of concrete implement like experiment and practical application of computer programs, Through this study, I found that over-all and more active researches on probability and statistics are required and that the studies about methods of loaming and teaching must be made in diverse directions. It is needed that how students recognize probability and statistics, connection, communication and representation in probability and statistics context, too. (series A) does not have papers on methods of study. Mathematics pedagogy is a mixture of various studies - mathematical psychology, mathematical philosophy, the history of mathematics and Mathematics. So If there doesn't exist a proper method of study adequate in the situation for the mathematics education the issue of mathematics pedagogy might be taken its own place by that of other studies'. We must search for the unique method of study fur mathematics education so that mathematics pedagogy has its own identity as a study. The study concerning this aspect is needed.

• Analytical Science and Technology
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• v.9 no.4
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• pp.336-344
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• 1996

The extraction of trace cobalt, copper, nickel, cadmium, lead and zinc in urine samples of organic and alkali metal matrix into chloroform by the complex with a dithizone was studied for graphite furnace AAS determination. Various experimental conditions such as the pretreatment of urine, the pH of sample solution, and dithizone concentration in a solvent were optimized for the effective extraction, and some essential conditions were also studied for the back-extraction and digestion as well. All organic materials in 100 mL urine were destructed by the digestion with conc. $HNO_3$ 30 mL and 30% $H_2O_2$ 50 mL. Here, $H_2O_2$ was added dropwise with each 5.0 mL, serially. Analytes were extracted into 15.0 mL chloroform of 0.1% dithizone from the digested urine at pH 8.0 by shaking for 90 minutes. The pH was adjusted with a commercial buffer solution. Among analytes, cadmium, lead and zinc were back-extracted to 10.00 mL of 0.2 M $HNO_3$ from the solvent for the determination, and after the organic solvent was evaporated, others were dissolved with $HNO_3-H_2O_2$ and diluted to 10.00 mL with a deionized water. Synthetic digested urines were used to obtain optimum conditions and to plot calibration-eurves. Average recoveries of 77 to 109% for each element were obtained in sample solutions in which given amounts of analytes were added, and detection limits were Cd 0.09, Pb 0.59, Zn 0.18, Co 0.24, Cu 1.3 and Ni 1.7 ng/mL, respectively. It was concluded that this method could be applied for the determination of heavy elements in urine samples without any interferences of organic materials and major alkaline elements.