• Steel and Composite Structures
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• 제49권4호
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• pp.441-456
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• 2023

Aiming at the development trend of light weight and high strength of engineering structures, this paper experimentally investigated the seismic performance of circular-in-square high-strength concrete-filled double skin steel tubular (HCFDST) stub columns with out-of-code width-to-thickness (B/t) ratios. Typical failure mode of HCFDST stub columns appeared with the infill material crushing, steel fracture and local buckling of outer tubes as well as the inner buckling of inner tubes. Subsequently, the detailed analysis on hysteretic curves, skeleton curves and ductility, energy dissipation, stiffness degradation and lateral force reduction was conducted to reflect the influences of hollow ratios, axial compression ratios and infill types, e.g., increasing hollow ratio from 0.54 to 0.68 and 0.82 made a slight effect on bearing capacity compared to the ductility coefficients; the higher axial compression ratio (e.g., 0.3 versus 0.1) significantly reduced the average bearing capacity and ductility; the HCFDST column SCFST-6 filled with concrete obviously displayed the larger initial secant stiffness with a percentage 34.20% than the column SCFST-2 using engineered cementitious composite (ECC); increasing hollow ratios, axial compression ratios could accelerate the drop speed of stiffness degradation. The out-of-code HCFDST stub columns with reasonable design could behave favorable hysteretic performance. A theoretical model considering the tensile strength effect of ECC was thereafter established and verified to predict the moment-resisting capacity of HCFDST columns using ECC. The reported research on circular-in-square HCFDST stub columns can provide significant references to the structural application and design.

• 한국해양학회지:바다
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• 제15권3호
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• pp.110-114
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• 2010

수영만에 설치된 모니터링 부이에서 관측된 해류, 바람, 파고자료와 부산항의 조석자료를 이용하여 강한 이안류가 발생했던 2009년 8월 13~15일의 물리환경을 분석하였다. 수영만의 조류는 단주기 해류성분과 비슷한 크기를 가지며 대조-소조에 따른 변화를 보인다. 이안류가 발생했을 때 북동풍이 강하게 불고 조류와 해류가 해운대 해안 쪽 방향으로 중첩되었다는 공통점이 있고, 8월 14일 오후에 이안류가 없었을 때는 파고와 조석은 유사한 조건이었지만 조류와 해류가 거의 반대방향이었다. 강한 바람은 큰 파랑을 동반하여 이안류 발생의 기본조건을 조성하지만 만 내의 해류에 미치는 국지적인 영향은 비교적 작다. 수영만에 인접한 세 해수욕장 중에서 해운대에서만 강한 이안류가 나타나는 데에는 해운대 중앙부의 특이하게 얕은 수중언덕이 외해에서 들어오는 파랑, 해류, 조류를 감쇠시키는 효과가 중요할 것으로 생각된다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제24권3호
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• pp.173-185
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• 2024

Background: Excessive fear of dental procedures leads to disruptive behavior during dental examinations and treatments. Dental examinations and treatments of these patients usually require additional techniques, such as sedation. The most commonly used techniques are inhalation of nitrous oxide, infusion of propofol with fentanyl, and premedication and infusion of midazolam. Methods: A prospective observational epidemiological study was conducted on patients who required sedoanalgesia techniques for dental exploration and procedures. The reasons for the inability of patients to cooperate (excessive fear or intellectual disability), age, sex, weight, systemic pathology, oral pathology, treatment performed, time of intervention, anesthetic technique performed, and occurrence of complications were recorded. Results: In total, 218 patients were studied. Sixty-five patients came for fear of dental treatment and 153 for presenting with a diagnosis of intellectual disability and not collaborating in the treatment with local anesthesia. The average age of all patients was 30.54±17.30 years. The most frequent oral pathologies found in patients with excessive fear were tartar (6.8%) and wisdom teeth (6.4%), followed by missing teeth (5%). In patients with disabilities, a combination of tartar and cavities appeared most frequently (41.3%), followed by cavities (15.6%). The most frequently used sedoanalgesia technique was the infusion of propofol with fentanyl in both groups of patients, followed by nitrous oxide. Conclusion: The combination of propofol and fentanyl was the most frequently used alternative in patients who were unable to collaborate because of intellectual disability or carry out longer or more complex treatments. Inhaled nitrous oxide and midazolam were the sedative techniques of choice for simpler oral treatments, such as tartrectomies, shallow obturations, and shorter interventions, or in younger patients.

• 산업경영시스템학회지
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• 제47권1호
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• pp.41-50
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• 2024

Korea is facing a significant problem with historically low fertility rates, which is becoming a major social issue affecting the economy, labor force, and national security. This study analyzes the factors contributing to the regional gap in fertility rates and derives policy implications. The government and local authorities are implementing a range of policies to address the issue of low fertility. To establish an effective strategy, it is essential to identify the primary factors that contribute to regional disparities. This study identifies these factors and explores policy implications through machine learning and explainable artificial intelligence. The study also examines the influence of media and public opinion on childbirth in Korea by incorporating news and online community sentiment, as well as sentiment fear indices, as independent variables. To establish the relationship between regional fertility rates and factors, the study employs four machine learning models: multiple linear regression, XGBoost, Random Forest, and Support Vector Regression. Support Vector Regression, XGBoost, and Random Forest significantly outperform linear regression, highlighting the importance of machine learning models in explaining non-linear relationships with numerous variables. A factor analysis using SHAP is then conducted. The unemployment rate, Regional Gross Domestic Product per Capita, Women's Participation in Economic Activities, Number of Crimes Committed, Average Age of First Marriage, and Private Education Expenses significantly impact regional fertility rates. However, the degree of impact of the factors affecting fertility may vary by region, suggesting the need for policies tailored to the characteristics of each region, not just an overall ranking of factors.

• Clinical Endoscopy
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• 제56권2호
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• pp.194-202
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• 2023

Background/Aims: Endoscopic therapy for neoplastic Barrett's esophagus (BE) has become the standard of care over the past two decades. In clinical practice, we regularly encounter patients who fail to achieve complete squamous epithelialization of the esophagus. Although the therapeutic strategies in the individual stages of BE, dysplasia, and esophageal adenocarcinoma are well studied and largely standardized, the problem of inadequate healing after endoscopic therapy is only marginally considered. This study aimed to shed light on the variables influencing inadequate wound healing after endoscopic therapy and the effect of bile acid sequestrants (BAS) on healing. Methods: Retrospective analysis of endoscopically treated neoplastic BE in a single referral center. Results: In 12.1% out of 627 patients, insufficient healing was present 8 to 12 weeks after previous endoscopic therapy. The average follow-up duration was 38.8±18.4 months. Complete healing was achieved in 13 patients already after intensifying proton pump inhibitor therapy. Out of 48 patients under BAS, 29 patients (60.4%) showed complete healing. An additional eight patients (16.7%) improved, but only partial healing was achieved. Eleven (22.9%) patients showed no response to BAS augmented therapy. Conclusions: In cases of insufficient healing even under exhaustion of proton pump inhibitors, treatment with BAS can be an option as an ultimate healing attempt.

• Hip & pelvis
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• 제35권1호
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• pp.24-31
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• 2023

Purpose: A response to conservative treatment is usually obtained in cases of ischiogluteal bursitis. However, the time required to achieve relief of symptoms can vary from days to weeks, and there is a high recurrence rate, thus invasive treatment in addition to conservative treatment can occasionally be effective. Therefore, the aim of this study was to examine surgical excision in cases of refractory ischiogluteal bursitis and to evaluate patients' progression and outcome. Materials and Methods: A review of 21 patients who underwent surgical excision for treatment of ischiogluteal bursitis between February 2009 and July 2020 was conducted. Of these patients, seven patients were male, and 14 patients were female. Injection of steroid and local anesthetic into the ischial bursa was administered at outpatient clinics in all patients, who and they were refractory to conservative treatment, including aspiration and prescription drugs. Therefore, surgery was considered necessary. Excisions were performed by two orthopedic specialists using a direct vertical incision on the ischial area. A review of each patient was performed after excision, and quantification of the outcomes recorded using clinical scoring systems was performed. Results: The results of radiologic evaluation showed that the mean lesion size was 6.2 cm×4.5 cm×3.6 cm. The average disease course after excision was 21.6 days (range, 15-48 days). Measurement of clinical scores, including the visual analog scale and Harris hip scores, was performed during periodic visits, with scores of 0.7 (range, 0-2) and 98.1 (range, 96-100) at one postoperative month, respectively. Conclusion: Surgical excision, with an expectation of favorable results, could be considered for treatment of ischiogluteal bursitis that is refractory to therapeutic injections, aspirations, and medical prescriptions, particularly in moderate-to-severe cases.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4317-4328
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• 2023

To ensure the measuring accuracy of the wall temperature, the outer wall temperature measurement values by using three kinds of thermocouple welding methods were analyzed and evaluated in the paper, including single-point flush-mounted in the wall groove method, single-point insert-mounted in the wall groove, and outer surface direct welding method, based on the application of a tube-in-tube condensing heat exchanger. And the impacts of silver, tin, and thermal resistance adhesive as filling materials on wall temperature measurement were also investigated, and the results were compared to that obtained without filling materials. The results showed that the wall temperatures measured by the three welding methods were lower than the theoretically calculated value. And the wall temperature measured by the outer surface direct welding method was lowest under the same experimental conditions. The wall temperatures measured by single-point flush-mounted and insert-mounted in the wall groove methods were also affected by different welding filling materials. It was found that the greater the thermal resistance of filling materials, the smaller the heat loss. By analyzing the reasons for the low measured value of wall temperature, a new wall temperature measurement method was developed to improve the accuracy of the current measurement method. Meanwhile, the outer wall temperature measurement experiments of vertical and horizontal heat transfer tubes were carried out to validate and calibrate the improved outer wall temperature measurement method. The results showed that the average outer wall temperature deviation measured by the improved wall temperature measurement method ranged from - 0.82% to +2.29% for vertical tubes and - 4.75% to - 1.44% for horizontal tubes, and the improved measurement method had good measurement accuracy.

• Journal of Ecology and Environment
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• 제48권1호
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• pp.110-119
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• 2024

Background: The Mae Kha Canal is one of Chiang Mai's most important waterways. It supports local agriculture, irrigation, and transportation as well as provides stormwater drainage to prevent floods. Due to the unregulated rapid urbanization of the city and lack of efficient waste and wastewater management systems over the past few decades, the canal has become heavily polluted. This study aimed to evaluate the water quality of Mae Kha canal through assessment of the physico-chemical water quality and coliform bacteria. Moreover, benthic macroinvertebrates were samples and assessed using the Biological Monitoring Working Party (BMWP^Thai) and Average Score Per Taxon (ASPT^Thai) as biological indices. Results: The physico-chemical showed low dissolved oxygen levels, high levels of ammonia and phosphates, and elevated levels of biochemical oxygen demand, indicating that the water quality had significantly deteriorated. The canal was found to be heavily polluted, with most sites falling into the polluted to very heavily polluted. Coliform bacteria analysis revealed alarmingly high levels of total coliform bacteria and fecal coliform bacteria in the canal. The BMWP^Thai and ASPT^Thai scores indicated poor to very poor water quality. Conclusions: The physico-chemical and coliform bacteria indicated that the water quality of the Mae Kha canal had significantly deteriorated. The biological indices also indicated the poor to very poor water quality. This study underscores the urgent need for comprehensive remediation efforts, emphasizing strategic planning, investment, and community engagement to revive the canal's ecological health and water quality.

• 보건행정학회지
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• 제10권3호
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• pp.19-49
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• 2000

보건소 조직구조에 대한 인식도 점수는 5 점척도 기준으로 재량권 필요성에 대한 인식도가 3.55 점으로 가장 높았고 보건소 조직구조에 대한 일반적 인식이 3.06점, 업무분장의 적합성 3.05점, 인력ㆍ예산의 적정성이 2.93 점, 의사결정권 소재에 대한 인식이 2.77 점 순이었다. 보건소 조직구조에 대한 직원들의 일반적 인식도 점수는 중소도시에서, 50 대 이상에서, 고졸 이하에서, 6급이상에서, 공무원 근무경력이 20년이상에서, 현부서 근무기간이 2년이하에서, 월평균 보수가 181만원이상에서 각각 타 군보다 높았으며 이들 변수들은 유의한 관련성이 있었다 그리고 의사결정권 소재에 대한 인식도 점수는 대도시에서, 남자에서, 기혼자에서, 6급이상자에서, 보건ㆍ행정직에서, 월평균 보수가 131-180 만원에서 각각 타 군보다 높았으며 이들 변수들은 유의한 관련성이 있었다. 재량권 필요성에 대한 인식도 점수는 20 대에서, 미혼자에서, 대졸이상자에서, 간호직에서, 공무원 근무경력이 5년이하자에서, 현부서 근무기간이 2년 이하자에서, 월평균 보수가 80 만원 이하자에서 각각 타 군보다 높았다. 인력ㆍ예산 적정성에 대한 인식도 점수는 여자에서,30 대에서, 기혼자에서,8 급에서, 보건ㆍ행정직에서, 현부서 근무기간 2-4년인자에서 각각 타 군보다 높았다. 그리고 업무분장의 적합성에 대한 인식도 점수는 중소도시에서, 기혼자에서, 의료기술직에서, 공무원 근무경력이 20 년이상자에서, 현부서 근무기간이 4년이하자에서 각각 타 군보다 높았으며 이틀 변수들은 유의한 관련성이 있었다, 보건소 직원들의 보건소 조직관리에 대한 인식도 조사에서 의사결정시 의견반응에 관한 인식도가 2.92 점으로 가장 높았으며, 목표량 설정방법의 합리성에 관한 인식이 2.88점, 보건소 인사관리에 대한 인식이 2.63점이었다. 보건소 인사관리에 대한 인식도 점수는 중소도시에서, 40대에서, 6급 이상자에서, 의료기술직에서, 공무원 근무경력이 20년 이상자에서, 현부서 근무기간이 2년 이하자에서, 월평균 보수가 181만원 이상자에서 각각 타 군보다 높았으며 이들 변수들은 유의한 관련성이 있었다. 의사결정시 의견반응에 관한 인식도 점수는 중소도시에서, 여자에서, 8급에서, 보건ㆍ행정직에서, 현부서 근무기간 2 년 이하자에서 각각 타 군보다 높았으며, 목표량 설정방법의 합리성에 관한 인식도 점수는 50대 이상에서, 고졸 이하자에서,6 급 이상 자에서, 의무직에서, 공무원 근무경력 15-20 년인 자에서 각각 타 군보다 높았으며 이들 변수들은 유의한 관련성이 있었다. 직무만족도에 유의하게 영향을 미치는 요인은 성, 교육정도, 업무분장의 적합성, 목표량 설정방법의 합리성에 관한 인식, 동기요인, 위생요인 이었으며, 조직문화에 유의하게 영향을 미치는 요인은 연령, 공무원 근무경력, 현부서 근무기간, 보건소 인력ㆍ예산의 적정성에 대한 인식, 업무분장의 적합성, 의사결정시 의견반응에 관한 인식, 목표량 설정방법의 합리성에 관한 인식이었다.

• 식물분류학회지
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• 제46권2호
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• pp.256-266
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• 2016

한국의 멸종위기 난과 식물인 석곡 13,000 촉을 증식하여 2013년 6월에 완도군 보길도 일대의 자연 서식지에 복원하였다. 연구팀은 복원 후 2년간 생장과정을 모니터링 하였다. 모본의 확보, 교배, 종자형성, 파종, 계대배양, 순화배양 등의 과정을 거쳐 복원할 13,000 촉을 육성하였다. 복원 전에 5개 엽록체 마커와 핵 ITS 지역을 이용하여 복원할 개체들의 유전적 다양성을 검증한 결과 국내의 자연집단 사이에서 관찰되는 수준의 유전적 다양성이 입증되었다. 현지복원은 연구팀과 지역주민들과의 공조체계를 구축하여 협동으로 수행하였다. 복원 이후 1년, 2년의 시점에 생존율, 영양번식률, 생장률 등을 조사하여 자료화 하였다. 복원 후 훼손은 없었으며, 97% 이상의 생존율을 보였다. 복원 후 영양번식이 활발하여, 복원 시점보다 촉수가 227%로 증가하였다. 그러나 복원당시에 비하여 개체의 평균 길이는 짧아졌다. 완전한 양지나 음지에 비해서 반음지 지역에서 석곡 개체들은 가장 잘 번식하고 생장하였다. 또한 부착한 기주 식물에 따라서 영양번식률 및 생장률에 차이를 보였다. 그늘쪽 바위틈과 참가시나무의 수피에 부착한 개체들이 가장 활발하게 증식하였고, 동백나무 수피에 부착하는 개체들이 세 번째 높은 증식률을 보였다. 일부 복원 개체들은 야생에서 꽃을 피우고, 수분되어 종자가 결실되는 것을 확인하였다. 전반적으로 복원한 개체의 촉수가 크게 증가하여 성공적인 복원으로 평가된다. 인위적인 훼손방지를 위하여 국립공원 및 지역주민들과 공조체제를 구축하였고, CCTV를 설치하여 감시활동을 하고 있다.