• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.12
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• pp.1351-1358
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• 2012

In this paper, an analytical technique is proposed for the design of interleaved thinned planar array with well-behaved and predictable sidelobes. The interleaved arrays are composed of thinned planar subarrays based on cyclic difference sets(DSs). Becauce sidelobes of thinned planar subarrays based on DS are predictable by DS parameters, the subarrays exhibit very similar sidelobe levels by utilizing DS and complementary DS with similar autocorrelations each other. The combinatorial method also allows the design of interleaved placements with simultaneously optimum peak sidelobe levels(PSLs) of subarrays using cyclic shift-a property of DSs. The optimized PSLs of the interleaved array are -12.47 dB and -10.34 dB.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.270-272
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• 2013

In order to protect coastal facilities mainly from wave and current actions, the self-locking bio blocks constituting component elements of protecting structures against scouring were designed. These blocks are adapted to the sloping bottom, coastal dunes, and submerged coastal base counteracting the destructive and erosive impulse action. A series of laboratory experiments is necessary to investigate the reflection of water waves over and against a train of protruded or submerged shore structures and compare the reflecting capabilities of incident waves including wave forces. In this study the hydraulic model experiment was conducted to identify the performance of newly designed water affinity bio blocks to keep the coast slope and bottom mound from scouring by reduction of the reflection coefficient and to convince stability of the placements. Revised design of each element of blocks were also tested for field conditions. From the result of experiment, the field applicability of the developed blocks and placement is to be discussed afterward.

• Earthquakes and Structures
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• v.16 no.3
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• pp.265-277
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• 2019

Framed masonry wall structures represent a typical high-rise structural system that are also seismically vulnerable. During ground motions, they are excited in both in-plane and out-of-plane terms. The interaction between the frame and the infill during ground motion is a highly investigated phenomenon in the field of seismic engineering. This paper presents a numerical investigation of two distinct static out-of-plane loading methods for framed masonry wall models. The first and most common method is uniformly loaded infill. The load is generally induced by the airbag. The other method is similar to in-plane push-over method, involves loading of the frame directly, not the infill. Consequently, different openings with the same areas and various placements were examined. The numerical model is based on calibrated in-plane bare frame models and on calibrated wall models subjected to OoP bending. Both methods produced widely divergent results in terms of load bearing capabilities, failure modes, damage states etc. Summarily, uniform load on the panel causes more damage to the infill than to the frame; openings do influence structures behavior; three hinged arching action is developed; and greater resistance and deformations are obtained in comparison to the frame loading method. Loading the frame causes the infill to bear significantly greater damage than the infill; infill and openings only influence the behavior after reaching the peak load; infill does not influence initial stiffness; models with opening fail at same inter-storey drift ratio as the bare frame model.

• The Journal of Internal Korean Medicine
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• v.41 no.6
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• pp.1289-1299
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• 2020

Background: Hemorrhoid surgery is a frequently performed surgery in Korea, second only to cataract surgery. However, it has serious complications, including bleeding, infection, anal stenosis, and urinary retention, so active conservative therapies are in need at an early stage. Case summary: Thirteen patients with anal disease complained of main symptoms of pain, bleeding, and prolapse, with additional complaints of itching and mucus discharge. An herbal medicine mixture of Eulja-tang and Hwangryeonhaedok-tang was administered twice daily, and dry cupping therapy, acupuncture, and hot pack placements were administered on pelvic and sacral regions once weekly for four weeks. The symptoms were evaluated before and each week after the treatments. The treatments had statistically significant therapeutic effects. Conclusion: Korean medicine treatment-effectively alleviating the symptoms of anal disease, such as pain, bleeding, and prolapse-may represent an alternative therapy for conservative treatments in the early stages of anal disease.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.1
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• pp.100-108
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• 2021

Purpose: Percutaneous endoscopic gastrostomy (PEG) tube placements are commonly performed pediatric endoscopic procedures. Because of underlying disease, these patients are at increased risk for airway-related complications. This study compares patient characteristics and complications following initial PEG insertion with general endotracheal anesthesia (GETA) vs. anesthesia-directed deep sedation with a natural airway (ADDS). Methods: All patients 6 months to 18 years undergoing initial PEG insertion within the endoscopy suite were considered for inclusion in this retrospective cohort study. Selection of GETA vs. ADDS was made by the anesthesia attending after discussion with the gastroenterologist. Results: This study included 168 patients (GETA n=38, ADDS n=130). Cohorts had similar characteristics with respect to sex, race, and weight. Compared to ADDS, GETA patients were younger (1.5 years vs. 2.9 years, p=0.04), had higher rates of severe American Society of Anesthesiologists (ASA) disease severity scores (ASA 4-5) (21% vs. 3%, p<0.001), and higher rates of cardiac comorbidities (39.5% vs. 18.5%, p=0.02). Significant associations were not observed between GETA/ADDS status and airway support, 30-day readmission, fever, or pain medication in unadjusted or adjusted models. GETA patients had significantly increased length of stay (eβ=1.55, 95% confidence interval [CI]=1.11-2.18) after adjusting for ASA class, room time, anesthesia time, fever, and cardiac diagnosis. GETA patients also had increased room time (eβ=1.20, 95% CI=1.08-1.33) and anesthesia time (eβ=1.50, 95% CI=1.30-1.74) in adjusted models. Conclusion: Study results indicate that younger and higher risk patients are more likely to undergo GETA. Children selected for GETA experienced longer room times, anesthesia times, and hospital length of stay.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.4
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• pp.337-344
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• 2021

Background: The primary indication for using long-acting anesthetics in dentistry is extensive dental procedures that require pulpal anesthesia beyond 90 min and management of postoperative pain. Ropivacaine is an amide local anesthetic that is available at various concentrations with inherent vasoconstrictive properties at low concentrations. Ropivacaine has a 75% greater margin of safety than bupivacaine. Ropivacaine can be a good alternative to bupivacaine as a local anesthetic in dental implant surgery as it provides a longer duration of both pulpal and soft tissue anesthesia after mandibular nerve block and lowers CNS and cardiovascular toxicity. This study aimed to evaluate and compare the clinical efficacy of ropivacaine and lignocaine for implant surgery anesthesia. Methods: Fifteen patients with bilateral edentulous sites indicated for implant placement were recruited for this study. Patients aged 20-60 years of both sexes were randomly recruited. Thirty implant placements were performed in the test and control groups using ropivacaine and lignocaine with adrenaline as local anesthetics, respectively. Results: The results were analyzed statistically. The duration of anesthesia was significantly higher in the test group than in the control group. Ropivacaine was found to be superior to lignocaine in terms of the quality of anesthesia. The comparison of mean visual analog scale scores showed ropivacaine to have better anesthetic and analgesic effects than the control group. Conclusion: Ropivacaine 0.75% provides a significantly longer duration of anesthesia than lignocaine 2% with adrenaline. Ropivacaine 0.75% decreased intraoperative and postoperative analgesia compared to lignocaine 2% with adrenaline. Hence, ropivacaine 0.75% can be used as an alternative to lignocaine in implant surgeries and other intraoral surgical procedures that require a longer duration of anesthesia and analgesia.

• Journal of KIBIM
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• v.12 no.4
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• pp.104-115
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• 2022

Fine Dust in Korea has been classified as a social disaster since 2019 due to continuous increase in concentration of Particulate Matter 10(PM 10) and PM 2.5. The fine dust issue has negative physical and mental impacts, especially on vulnerable population including children and the elderly. Seoul metropolitan government have installed fine dust shelters since 2019. However, there is a lack of research that evaluates spatiotemporal distribution of these facilities. Therefore, the first aim of this study is to find the relationship between PM levels and dust scattering construction sites, or air pollutant emission sites through in depth spatial analyses. The second purpose is to analyze the spatial distribution of PM shelters in Seoul, and to evaluate the location efficiency of them. Kernel density, krigging, and network analyses were conducted, and floating population was considered instead of census data for this research. The reults of network analysis based on the road system showed that Yangcheon-gu, Songpa-gu, Seongbuk-gu, and Dobong-gu were found to need additional fine dust shelters. Also, the results from analyzing the floating population that includes children and the elderly showed that Songpa-gu, Seodaemun-gu, Gangdong-gu, Seocho-gu, and Dongdaemun-gu need more placements of find dust shelters. The results of this study are expected to provide implications for urban planners to enhance find dust shelter placement in urban areas, and vulnerable population issues would be considered in many ways.

• Korean Journal of Acupuncture
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• v.40 no.1
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• pp.13-17
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• 2023

Objectives : Our goals were to examine how the well points in the fingers came to be and how their placements have changed, as well as to determine how they relate to the EX-UE11 points. Methods : We reviewed the classic textbooks to understand the origin and the changes of locations of the well points in the fingers. We also compared the location and indications between well points in the fingers and EX-UE11 points. Results : At first, the tips of the fingers, which are now thought to be the locations of EX-UE11 points, were once described as containing well points. Currently, well points are positioned 0.1 F cun distal-medial (or lateral) to the medial (or lateral) corner of the nail. In addition to the locational commonality, we found similarities between the well points in the fingers and the EX-UE11 points in terms of their indications; for example, bloodletting at these places is frequently utilized to treat emergencies, including acute stroke and fever. Conclusions : We suggest that it is highly likely that well points in the fingers and EX-UE11 points were initially the same acupuncture point and later classified into two different acupuncture points, given their identical locations and indications. If the clinical relevance between the change process of the well points' locations in the fingers and the EX-UE11 is studied in the historical literature, it is anticipated that the significance and clinical application of well points can be expanded.

• Korean Journal of Childcare and Education
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• v.19 no.3
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• pp.19-39
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• 2023

Objective: The purpose of this study was to analyze the experiences of foreign students in childcare practicum, with a specific focus on identifying the difficulties they encountered and the values they derived from their practicum experiences. The aim was to gain insights that can contribute to improving practicum support for these students. Methods: A total of 6 foreign students were selected as participants for this study using snowball sampling. The data collection period spanned from May 2021 to March 2023, during which semi-structured interviews were conducted and qualitatively analyzed. Results: Foreign students faced challenges in securing practicum placements prior to the start of their program. Communication difficulties necessitated the use of interpreters to interact with children. Additionally, documenting information in a language other than their mother tongue posed a challenge. Consequently, there was a need for tailored training support to address the specific needs of foreign students in childcare practicum. Despite these challenges, the students reported rewarding and valuable experiences during their practicum. These experiences included discovering the teaching identity in Korea, learning about desirable practices in the field, recognizing and addressing personal shortcomings, and developing a sense of vocation for the advancement of infant education in their home countries. Conclusion/Implications: If we actively listen to and provide appropriate support for the specific needs of foreign students in their childcare practicum, they have the potential to become excellent childcare teachers who can foster a harmonious and inclusive environment within our multicultural society.

• Smart Structures and Systems
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• v.31 no.3
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• pp.247-257
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• 2023

In structural health monitoring of large-scale structures, optimal sensor placement plays an important role because of the high cost of sensors and their supporting instruments, as well as the burden of data transmission and storage. In this study, a vibration sensor placement algorithm based on deep reinforcement learning (DRL) is proposed, which can effectively solve non-convex, high-dimensional, and discrete combinatorial sensor placement optimization problems. An objective function is constructed to estimate the quality of a specific vibration sensor placement scheme according to the modal assurance criterion (MAC). Using this objective function, a DRL-based algorithm is presented to determine the optimal vibration sensor placement scheme. Subsequently, we transform the sensor optimal placement process into a Markov decision process and employ a DRL-based optimization algorithm to maximize the objective function for optimal sensor placement. To illustrate the applicability of the proposed method, two examples are presented: a 10-story braced frame and a sea-crossing bridge model. A comparison study is also performed with a genetic algorithm and particle swarm algorithm. The proposed DRL-based algorithm can effectively solve the discrete combinatorial optimization problem for vibration sensor placements and can produce superior performance compared with the other two existing methods.