• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.5
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• pp.399-406
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• 2019

The variation of ground-penetrating radar(GPR) signal characteristics from dielectric-filled nonmetallic pipes buried in inhomogeneous ground are compared through a numerical simulation. The relative permittivity distribution of the ground is generated by using the continuous random media(CRM) technique. As a function of the relative permittivity of the material filling the nonmetallic pipe buried in the ground media, GPR signals are simulated by using the finite-difference time-domain(FDTD) method. We show that, unlike the case for homogeneous ground, the distortion characteristics of the reflected waves caused by the front convex surface and the rear concave surface of the pipe buried in inhomogeneous ground are different depending on the permittivity contrast between the inside and outside of the pipe.

• Journal of Trauma and Injury
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• v.34 no.2
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• pp.112-118
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• 2021

Purpose: Negative laparotomy in patients with abdominal penetrating injuries (APIs) is associated with deleterious outcomes and unnecessary expense; however, the indications for laparotomy in hemodynamically stable patients with ambiguous computed tomography (CT) findings remain unclear. This study aimed to identify the factors associated with negative laparotomy. findings Methods: Data of patients who underwent laparotomy for APIs between 2011 and 2019 were retrospectively reviewed. Patients who presented with definite indications for laparotomy were excluded. The patients were dichotomized into negative and positive laparotomy groups, and the baseline characteristics, laboratory test results, and CT findings were compared between the groups. Results: Of 55 patients with ambiguous CT findings, 38 and 17 patients were assigned to the negative and positive laparotomy groups, respectively. There was no significant difference between the groups with respect to the baseline characteristics or the nature of the ambiguous CT findings. However, the laboratory test results showed that there was a difference in the percentage of neutrophils between the groups (negative: 55.6% [range 47.4-66.1%] vs. positive: 79.8% [range 77.6-88.2%], p<0.001), although the total white blood cell count was not significantly different. The mean duration of hospital stay for the negative laparotomy group was 13.1 days, and seven patients (18.4%) experienced complications. Conclusions: Diagnostic factors definitively indicative of laparotomy were not identified, although the percentage of neutrophils might be helpful. However, routine laparotomy in patients with peritoneal injuries could result in instances of negative laparotomy.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.4
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• pp.166-172
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• 2021

Obstacle Limitation Surfaces (OLS) are set to protect a certain amount of airspace to limit objects, such as building, other structures, penetrating OLS for safety and regularity of aircraft operations in the vicinity of aerodromes. However, many civil petitions have been raising for effective utilization of lands and permission of building construction which penetrating OLS. While Republic of Korea are limiting installation of penetrating objects based on the National law of airport facilities, such objects are possibly permitted, only if, the possible risks coming from objects are acceptable or negligible in terms of safety and regularity in aircraft operations through the evaluation process, called as an aeronautical study. However, many countries are currently applying their own criteria, processes resulting in failing secure reliable results in aeronautical study. This research aims to establish the framework on criteria, process, and methodologies how the aeronautical study works including work flows between many stakeholder and responsibilities to be specified in national regulation system.

• Journal of Trauma and Injury
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• v.35 no.2
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• pp.118-122
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• 2022

The usual cause of penetrating thoracoabdominal injuries with evisceration are stab wounds with knives and other sharp weapons used during fights and conflicts. Evisceration of the abdominal viscera as a result of trauma, with its attendant morbidity and mortality, requires early intervention. Gunshot wounds can also cause penetrating thoracoabdominal injuries. We report the case of a 52-year-old male patient, a worker at a timber-processing factory, who was assaulted with a chainsaw by his colleague following a disagreement. He was seen at the accident and emergency department of Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria with a thoracoabdominal injury about 1.5 hours after the attack. He had a left thoracoabdominal laceration with abdominal evisceration and an open left pneumothorax. He was managed operatively, made a full recovery, and was discharged 16 days after admission. He was readmitted 4 months after the initial surgery with acute intestinal obstruction secondary to adhesions. He underwent exploratory laparotomy and adhesiolysis. He made an uneventful recovery and was discharged on the 9th postoperative day for subsequent follow-up.

• Journal of Trauma and Injury
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• v.36 no.3
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• pp.253-257
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• 2023

A century ago, cardiac injuries usually resulted in death. However, despite all the advances in medicine, these injuries still have high mortality and morbidity rates. In the present case, we describe a patient with a bullet injury to the right ventricle who survived at our hospital despite the limitations of our center with regard to modalities and equipment. A 30-year-old man was brought to our emergency department with a bullet wound to his left flank. He was hemodynamically unstable. After only 8 minutes in the hospital and without further investigations he was rushed to the operating room. During laparotomy, a clot was visible in the left diaphragm, which dislodged and caused extensive bleeding. The decision was made to perform a sternotomy in the absence of a sternal saw. An oblique 8-cm injury to the right ventricle was discovered following rapid exploration. It was repaired without the need for cardiopulmonary bypass surgery. After a few days in the hospital, the patient was discharged home. In the event of a penetrating cardiac injury, rapid decision-making is crucial for survival. Whenever possible, the patient should be transferred to the operating room, as emergency department thoracotomies are associated with a high mortality rate.

• Geomechanics and Engineering
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• v.38 no.1
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• pp.29-44
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• 2024

This research investigates the effectiveness of data augmentation techniques in the automated analysis of B-scan images from ground-penetrating radar (GPR) using deep learning. In spite of the growing interest in automating GPR data analysis and advancements in deep learning for image classification and object detection, many deep learning-based GPR data analysis studies have been limited by the availability of large, diverse GPR datasets. Data augmentation techniques are widely used in deep learning to improve model performance. In this study, we applied four data augmentation techniques (geometric transformation, color-space transformation, noise injection, and applying kernel filter) to the GPR datasets obtained from a testbed. A deep learning model for GPR data analysis was developed using three models (Faster R-CNN ResNet, SSD ResNet, and EfficientDet) based on transfer learning. It was found that data augmentation significantly enhances model performance across all cases, with the mAP and AR for the Faster R-CNN ResNet model increasing by approximately 4%, achieving a maximum mAP (Intersection over Union = 0.5:1.0) of 87.5% and maximum AR of 90.5%. These results highlight the importance of data augmentation in improving the robustness and accuracy of deep learning models for GPR B-scan analysis. The enhanced detection capabilities achieved through these techniques contribute to more reliable subsurface investigations in geotechnical engineering.

• Journal of Acupuncture Research
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• v.29 no.2
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• pp.1-8
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• 2012

Objectives : This study was performed to compare the effects between Mountain-burning fire method and Heaven-penetrating cooling method on thermographic change. Materials and Methods : The experiment was conducted to 20 students of College of Oriental Medicine, Woosuk University from July 12, 2011 to July 26, 2011. Acupuncture stimulation was applied at left $Zusanli$($ST_{36}$) with Mountain-burning fire method in A group(n=10) and Heaven-penetrating cooling method in B group (n=10). To estimate thermographic change, temperature of left $Zusanli$($ST_{36}$), $Shuigou$($GV_{26}$), $Zhongwan$($CV_{12}$) were measured by DITI(digital infrared thermographic image) before acupuncture stimulation and 30sec, 10min after needle removal. Results : In A group, the temperature of left $Zusanli$($ST_{36}$), $Shuigou$($GV_{26}$), $Zhongwan$($CV_{12}$) were decreased at 30sec after needle removal, statistically. And the temperature of $Zusanli$($ST_{36}$), $Zhongwan$($CV_{12}$) were decreased at 10min after needle removal, statistically. In B group, the temperature of $Zusanli$($ST_{36}$), $Zhongwan$($CV_{12}$) were decreased at 10min after needle removal, statistically. But, there was no significant difference between two groups on thermographic change, statistically Conclusions : Acupuncture stimulation applied at left $Zusanli$($ST_{36}$) with Mountain-burning fire method has more widespread effects than Heaven-penetrating cooling method. But further studies will be needed such as thermographic change with no stimulation and with more subjects.

• Journal of Chest Surgery
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• v.36 no.1
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• pp.30-34
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• 2003

As classical acute aortic dissection, atherosclerotic penetrating ulcers and intramural hematoma have different pathophysiology and natural history, treatment strategy should be different and, therefore, accurate differential diagnosis is necessary. However, these three aortic diseases may be indistinguishable by clinical observation and even by various diagnostic modalities such as cardiac echocardiography, CT and MRI. The patients was a 71-year-old female with chief complaints of anterior chest pain, nausea and vomiting which occurred suddenly 3 days before admission. CT angiographic with 3 dimensional reconstruction shows intramural hematoma in ascending aorta, aortic arch, descending thoracic aorta and right brachiocephalic trunk, heompericardium, and blood in mediastinum and both pleural cavities. The CT angiographic finding of focal out-bulging in the ascending thoracic aorta was diagnosed as penetrating atherosclerotic ulcer. The patient underwent emergency operation under a preoperative diagnosis of penetrating atherosclerotic ulcer with a sign of aortic rupture. In the intraoperative findings, however, intimal tear was seen in the anterior portion of the ascending aorta about 1cm below the brachiocephalic trunk and falselumen appeared after hematoma was removed from the layer of tunica media. We report a case of type A aortic dissection which mimicked clinical and diagnostic features of penetrating atherosclerotic ulcer.

• Journal of Trauma and Injury
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• v.23 no.2
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• pp.107-112
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• 2010

Purpose: Recently, the change to a more complex social structure has led to an increased frequency of traumas due to violence, accident and so on. In addition, the severity of the traumas and the frequency of penetrating injuries have also increased. Traumas to cervical and abdominal areas, what are commonly seen by general surgeons, can have mild to fatal consequences because in these areas, various organs that are vital to sustaining life are located. The exact location and characteristics of the injury are vital to treating patients with the trauma to these areas. Thus, with this background in mind, we studied, compared, and analyzed clinical manifestations of patients who were admitted to Wonju Christian hospital for penetrating injuries inflicted by themselves or others. Methods: We selected and performed a retrospective study of 64 patients who had been admitted to Wonju Christian Hospital from January 2005 to December 2009 and who had cervical or abdominal penetrating injuries clearly inflicted by themselves or others. Results: There were 51 male (79.7%) and 13 female (20.3%) patients, and the number of male patients was more dominant in this study, having a sex ratio of 3.9 to 1. The range of ages was between 20 and 86 years, and mean age was 43.2 years. There were 5 self-inflicted cervical injuries, and 19 self-inflicted abdominal injuries, making the total number of self-inflicted injury 24. Cervical and abdominal injuries caused by others were found in 11 and 29 patients, respectively. The most common area involved in self-inflicted injuries to the abdomen was the epigastric area, nine cases, and the right-side zone II was the most commonly involved area. On the other hand, in injuries inflicted by others, the left upper quadrant of the abdomen was the most common site of the injury, 14 cases. In the neck, the left-side zone II was the most injured site. In cases of self-inflicted neck injury, jugular vein damage and cervical muscle damage without deep organ injury were observed in two cases each, making them the most common. In cases with abdominal injuries, seven cases had limited abdominal wall injury, making it the most common injury. The most common deep organ injury was small bowel wounds, five cases. In patients with injuries caused by others, six had cervical muscle damage, making it the most common injury found in that area. In the abdomen, small bowel injury was found to be the most common injury, being evidenced in 13 cases. In self-inflicted injuries, a statistical analysis discovered that the total duration of admission and the number of patients admitted to the intensive care unit were significantly shorter and smaller, retrospectively, than in the patient group that had injuries caused by others. No statistically significant difference was found when the injury sequels were compared between the self-inflicted-injury and the injury-inflicted-by-others groups. Conclusion: This study revealed that, in self-inflicted abdominal injuries, injuries limited to the abdominal wall were found to be the most common, and in injuries to the cervical area inflicted by others, injuries restricted to the cervical muscle were found to be the most common. As a whole, the total duration of admission and the ICU admission time were significantly shorter in cases of self-inflicted injury. Especially, in cases of self inflicted injuries, abdominal injuries generally had a limited degree of injury. Thus, in our consideration, accurate injury assessment and an ideal treatment plan are necessary to treat these patients, and minimally invasive equipment, such as laparoscope, should be used. Also, further studies that persistently utilize aggressive surgical observations, such as abdominal ultrasound and computed tomography, for patients with penetrating injuries are needed.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.06a
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• pp.26-31
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• 2004