• Title/Summary/Keyword: Center Loss

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Development of a Rotation Swab Pig Method for Cleaning Water Pipes (상수관의 세척을 위한 회전식 스왑피그 공법 개발)

  • Kicheol Lee;Jaeho Kim;Kisung Kim;Jeongjun Park
    • Journal of the Korean Geosynthetics Society
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    • v.23 no.2
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    • pp.63-75
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    • 2024
  • Drinking water is an essential element to ensure the basic human right to live, and the quality of clean water must always be ensured. However, domestic water facilities, which were installed intensively in the early 2000s, are deteriorating. The accidents such as discoloration of water such as chromaticity and turbidity as well as leakage of substances frequently occur. However, since it is virtually impossible to replace all water pipes, the detailed standards for maintenance of water pipe network facilities established in 2021 require water pipe cleaning. The swab pig method, one of the water pipe cleaning methods, is a method of physically removing substances in pipes and is evaluated as having the highest cleaning efficiency. However, Swab is highly likely to be damaged or deformed during the cleaning process, and may even be lost. Therefore, in this study, the material of the pig was changed to a material with high compressibility, and it was made as close as possible to the inner wall of the water pipe. And, to maximize cleaning efficiency, a rotation swab pig with a rotation blade was developed. In addition, high-strength wire and winding equipment were additionally developed to eliminate the possibility of loss and to determine the location of the pig. The inlet and outlet are connected with wires, and after verifying the performance of each detailed technology, the technology was applied on a test bed with a 30m section. As a result of the application, the performance of the technology was verified by measuring the process time and evaluating applicability.

Analysis of biodiversity change trend on urban development project - Focusing on terrestrial species in Environmental Impact Assessment - (도시의 개발 사업에 따른 생물다양성 변화 추세 분석 - 환경영향평가의 육상 동물종을 중심으로 -)

  • Kim, Eun-Sub;Lee, Dong-Kun;Jeon, Yoon-Ho;Choi, Ji-Young;Kim, Shin-Woo;Hwang, Hye-Mi;Kim, Da-Seul;Moon, Hyun-Bin;Bae, Ji-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.6
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    • pp.21-32
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    • 2023
  • The Environmental Impact Assessment (EIA) plays a pivotal role in predicting the potential environmental impacts of proposed developments and planning appropriate mitigation measures to minimize effects on species. However, as concerns over biodiversity loss rise, there's ongoing debate about the efficacy of these mitigation plans. In this study, we utilized data from EIAs and post-environmental impact surveys to understand the trends in biodiversity during construction and operation phases. By examining 30 urban development projects, we categorized species richness indices of mammals, birds, amphibians, and reptiles into pre-construction, during construction, and post-construction operational stages. The biodiversity trends were analyzed based on the rate of change in these indices. The results revealed three distinct biodiversity change patterns: (A) An initial increase in biodiversity indices post-development, followed by a gradual decline over time; (B) a sustained increase in biodiversity as a result of mitigation measures; and (C) a continuous decline in biodiversity post-development. Furthermore, all species exhibited a higher rate of biodiversity decline during the construction phase compared to the operational phase, with mammals showing the most significant rate of change. Notably, the biodiversity change rate during operation was generally lower than during construction. In particular, mammals seemed to be most influenced by mitigation measures, displaying the smallest rate of change. This study provides empirical evidence on the efficacy of mitigation measures and deliberates on ways to enhance their effectiveness in minimizing the adverse impacts of urban development on biodiversity. These findings can serve as foundational data for addressing terrestrial biodiversity reduction.

Parenchymal-sparing anatomical hepatectomy based on portal ramification of the right anterior section: A prospective multicenter experience with short-term outcomes

  • Truong Giang Nguyen;Thanh Khiem Nguyen;Ham Hoi Nguyen;Hong Son Trinh;Tuan Hiep Luong;Minh Trong Nguyen;Van Duy Le;Hai Dang Do;Kieu Hung Nguyen;Van Minh Do;Quang Huy Tran;Cuong Thinh Nguyen
    • Annals of Hepato-Biliary-Pancreatic Surgery
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    • v.28 no.1
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    • pp.25-33
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    • 2024
  • Backgrounds/Aims: Parenchymal-sparing anatomical hepatectomy (Ps-AH) based on portal ramification of the right anterior section (RAS) is a new technique to avoid unnecessarily transecting too much liver parenchyma, especially in cases of major anatomical hepatectomy. Methods: We prospectively assessed 26 patients with primary hepatic malignancies having undergone major Ps-AH based on portal ramification of the RAS from August 2018 to August 2022 (48 months). The perioperative indications, clinical data, intra-operative index, pathological postoperative specimens, postoperative complications, and follow-up results were retrospectively evaluated. Results: Among the 26 patients analyzed, there was just one case that had intrahepatic cholangiocarcinoma The preoperative level of α-Fetoprotein was 25.2 ng/mL. All cases (100%) had Child-Pugh A liver function preoperatively. The ventral/dorsal RAS was preserved in 19 and 7 patients, respectively. The mean surgical margin was 6.2 mm. The mean surgical time was 228.5 minutes, while the mean blood loss was 255 mL. In pathology, 5 cases (19.2%) had microvascular invasion, and in the group of HCC patients, 92% of all cases had moderate or poor tumor differentiation. Six cases (23.1%) of postoperative complications were graded over III according to the Clavien-Dindo system, including in three patients resistant ascites or intra-abdominal abscess that required intervention. Conclusions: Parenchymal-sparing anatomical hepatectomy based on portal ramification of the RAS to achieve R0-resection was safe and effective, with favorable short-term outcomes. This technique can be used widely in clinical practice.

Clinical Outcomes After Drug-Coated Balloon Treatment in Popliteal Artery Disease: K-POP Registry 12-Month Results

  • Jong-Il Park;Young-Guk Ko;Seung-Jun Lee;Chul-Min Ahn;Seung-Woon Rha;Cheol-Woong Yu;Jong Kwan Park;Sang-Ho Park;Jae-Hwan Lee;Su-Hong Kim;Yong-Joon Lee;Sung-Jin Hong;Jung-Sun Kim;Byeong-Keuk Kim;Myeong-Ki Hong;Donghoon Choi
    • Korean Circulation Journal
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    • v.54 no.8
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    • pp.454-465
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    • 2024
  • Background and Objectives: The popliteal artery is generally regarded as a "no-stent zone." Limited data are available on the outcomes of drug-coated balloons (DCBs) for popliteal artery disease. This study aimed to evaluate the 12-month clinical outcomes among patients who received DCB treatment for atherosclerotic popliteal artery disease. Methods: This prospective, multicenter registry study enrolled 100 patients from 7 Korean endovascular centers who underwent endovascular therapy using IN.PACT DCB (Medtronic) for symptomatic atherosclerotic popliteal artery disease. The primary endpoint was 12-month clinical primary patency and the secondary endpoint was clinically driven target lesion revascularization (TLR)-free rate. Results: The mean age of the study cohort was 65.7±10.8 years, and 77% of enrolled patients were men. The mean lesion length was 93.7±53.7 mm, and total occlusions were present in 45% of patients. Technical success was achieved in all patients. Combined atherectomy was performed in 17% and provisional stenting was required in 11%. Out of the enrolled patients, 91 patients completed the 12-month follow-up. Clinical primary patency and TLR-free survival rates at 12 months were 76.0% and 87.2%, respectively. A multivariate Cox regression analysis identified female and longer lesion length as the significant independent predictors of loss of patency. Conclusions: DCB treatment yielded favorable 12-month clinical primary patency and TLR-free survival outcomes in patients with popliteal artery disease.

A Reaserch on the Performance Verification of Energy Storage Mortar Enhanced in Thermal Efficiency and Strength by Applying Microencapsulated Phase Change Materials and Nanomaterials (마이크로캡슐로 코팅한 상변화 물질과 나노소재를 적용한 고효율 열저장 시멘트 복합체 성능 검증 연구)

  • Ahn, Jun Hyuk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.4
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    • pp.433-441
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    • 2024
  • This study aims to prevent freezing of existing domestic buildings by developing an energy storage mortar with increased energy efficiency that can reduce the increase in carbon emissions and maintenance costs due to external energy use due to heat wires in civil engineering and buildings with embedded heat wires. I suggest. Research has focused on incorporating phase change materials (PCMs) into common cement composites to provide latent heat performance. However, concrete mixed with phase change materials shows problems such as leakage of phase change materials, decreased strength, and insufficient thermal performance. To overcome this problem, we encapsulate phase change materials using microcapsules and mix them into cement composites to minimize strength loss and leakage, and use multi-walled carbon nanotubes and silica fume to minimize the strength reduction of concrete. A heat storage cement composite was developed. When high-efficiency heat storage cement was used as a replacement for ordinary cement composite in an environment where heat wires were buried, the effect was shown to reduce energy by about 42 %, and compared to a cement composite containing only PCM, the compressive strength and bending strength were 18 % and 23 %, respectively. was improved and its effectiveness was proven.

Development of Suicide Prevention Programs for Mental Health Professionals Working with Children and Adolescens at High Risk of Suicide (아동·청소년 자살고위험군 자살예방평가 및 프로그램)

  • Yang, Jeong-Soon;Woo, Hee-Soon
    • Therapeutic Science for Rehabilitation
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    • v.13 no.3
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    • pp.37-50
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    • 2024
  • Korea has the highest suicide rate among Organization for Economic Cooperation and Development countries, with increasing rates observed among children and adolescents with low levels of life satisfaction. Patients in these age groups exhibit particularly turbulent and impulsive behaviors, which make suicide highly contagious and fatal. The loss of meaningful work or activities increases the risk of suicide, especially in young people. Following revisions to the Mental Health Welfare Act (2016), which has included occupational therapists among mental health professionals, a multidisciplinary approach including occupational therapy has been emphasized upon in mental health services. Screening tools for preventing suicide in children and adolescents include the Suicidal Ideation Scale, Beck's Suicidal Ideation Scale, Columbia-Suicide Severity Rating Scale, Reasons for Living Scale for Adolescents, and the Student Emotional and Behavioral Characteristics Test. The Canadian Occupational Performance Measure, which is an occupational therapy evaluation tool, is also used. Various suicide prevention programs have been proposed across academic disciplines; however, due to the urgent nature of high-risk groups, there is a need for timely services. Currently, most existing programs focus primarily on the cognitive-behavioral aspects. In this study, we aimed to introduce diverse suicide prevention programs for mental health professionals working with high-risk children and adolescents in order to equip them with the relevant information and help apply their learnings effectively in different situations.

Application and Development Strategies of a Secure Real-Time Operating System in Weapon Systems within the Defense Sector (국방분야 보안 RTOS의 무기체계 적용 및 발전 방안)

  • Sang-Seung Lee;Keun-Ha Choi;Seung-Hyeon Hwang;Hyun-Ji Kim;Kyung-Deok Seo;Hwa-Eun Seong
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.5
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    • pp.189-193
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    • 2024
  • As cyber threats increase in the defense sector, the security of weapon system software is becoming increasingly important. Currently, most of the embedded software installed in domestic weapon systems operates based on foreign real-time operating systems(RTOS) that have no security. As a result, the localization and security enhancement of embedded software for weapon systems have emerged as urgent tasks. This study aims to propose the application and development strategies of secure RTOS for weapon systems. To this end, we examined the technological trends of domestic and foreign RTOS and secure RTOS, and analyzed the problems of current embedded software in weapon systems. The results revealed major issues such as low localization, vulnerability to cyber attacks, difficulty in maintenance, increased costs, and loss of opportunities for accumulating technological capabilities. An investigation of the current status of embedded software applied to existing weapon systems found that embedded SW are in operation across all fields, including maneuver, firepower, protection, command and control, communication, naval vessels, and aircraft. Among them, 99% rely on foreign RTOS such as VxWorks. A review of the core functions and applicability of secure RTOS to weapon systems suggests that it can be applied to key areas requiring real-time performance and security, such as fire control, navigation devices, and flight control in existing and future weapon systems. However, ensuring performance and reliability, securing verification and compatibility, and systematic government support were raised as prerequisites.

Simulation Study to Verify Manned-Unmanned Teaming Operations in Indoor Fire Response (실내 화재 대응 시 유·무인 복합운용 검증을 위한 시뮬레이션 연구)

  • Jin-Hyeon Sung;Seong-Hyeon Ju;Bong Gu Kang;Kyung-Min Seo
    • Journal of the Korea Society for Simulation
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    • v.33 no.3
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    • pp.37-50
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    • 2024
  • In indoor disaster scenarios such as fires or gas leak, prompt rescue operations are essential to minimize expected casualties. This paper proposes a simulation model that applies the concept of Manned-Unmanned Teaming (MUM-T) for effective search and rescue in indoor fires. To this end, we first identify appropriate agents to model search and rescue operations. The proposed agent-based simulation consists of a fire and map model, an occupant model, a drone model for occupants searching, a rescuer model for searching and rescuing occupants, and a control center model that assigns missions to drones and rescuers. The agent models identified according to the MUM-T concept interact with other agents during the fire response simulation. Simulation experiments were conducted for search and rescue operations in three scenarios, one consisting of only rescuers and two with mixed rescuers and drones for MUM-T. The simulation results indicated that a drone applied to MUM-T could replace an average of four rescuers. The simulation method proposed in this study is expected to improve the efficiency of search and rescue operations in indoor disaster situations and minimizing the loss of life.

A survey of body shape perception and weight control of adolescent girls in three areas of Korea (청소년기 여학생의 외모에 대한 인식 및 체중조절 실태 조사)

  • Lee, Yoon;Shin, Hye-Kyoung;Choi, Byung-Min;Eun, Baik-Lin;Park, Sang-Hee;Lee, Kee-Hyoung;Shin, Chol
    • Clinical and Experimental Pediatrics
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    • v.51 no.2
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    • pp.134-144
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    • 2008
  • Purpose : This study aimed to investigate body shape perception, weight control behaviors and eating habits of adolescent girls in urban, suburban and rural areas of Korea to obtain basis for establishing adequate weight control program for adolescent. Methods : From May 2002 to November 2002, a cross-sectional questionnaire survey and physical examination were conducted to examine body shape perception, weight control behaviors, eating habits and health status of 2,891 adolescent girls and 891 boys in Seoul, Ansan and Paju. Results : The proportion of underweight adolescent girl was decreased in rural area than in urban area. 46.3% of girls considered themselves to be somehow or very obese. Notably 3.2% of underweight girls considered themselves obese. 57.9% were unsatisfied with their own body shape. The proportion of dissatisfaction increased with age and body mass index (BMI), but there were no differences among area. The experiences of weight control increased by age, BMI and dissatisfaction of own body shape. The eating attitudes test-26 (EAT-26) score of girls was significantly higher than that of boys. The girls with high risk of eating disorder were 10.9%. And risk factors of eating disorder were living in urban area, severe stress for weight control excessive expenditure for appearance and think themselves unhealthy. Conclusion : The findings of this study demonstrate that there were serious impairment of body shape perception of adolescent girls and unhealthy, inadequate weight control behaviors were widely done. Therefore adequate weight control program for adolescent girl should be established promptly.

Effects of Internal Temperature on Physical Properties of Hanwoo Beef Eye of Round and Center of Heel during Boiling (열탕 가열 중 한우 홍두깨살 및 아롱사태의 중심온도가 가열감량, 보수력, 표면색도 및 조직감에 미치는 영향)

  • Moon, Yoon-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.4
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    • pp.403-412
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    • 2013
  • In this experiment, the effect of internal temperature on the physical properties of Hanwoo beef eye of round (ER) and center of heel (CH) during boiling was investigated. The pH value of Hanwoo beef ER and CH began to increase significantly (p<0.05) compared to raw meat around an internal temperature of $40^{\circ}C$ and $50^{\circ}C$, respectively; in addition, it showed the biggest changes around $70^{\circ}C$ and $80^{\circ}C$, respectively. No significant difference beyond the temperatures noted above was observed. The $L^*$ value of Hanwoo beef ER and CH began to increase significantly around an internal temperature of $50^{\circ}C$ and $60^{\circ}C$, respectively, while the $a^*$ and $b^*$ values kept decreasing up to $80^{\circ}C$ (p<0.05). None of these values showed a significant difference beyond the threshold temperature ($50{\sim}60^{\circ}C$ for the $L^*$ value, $80^{\circ}C$ for the $a^*$ and $b^*$ values). Hanwoo beef ER and CH showed the highest cooking loss and lowest water holding capacity around an internal temperature of $60^{\circ}C$ and $70^{\circ}C$, respectively. No significant difference was observed beyond those temperatures. The hardness, gumminess and chewiness of Hanwoo beef ER and CH showed the biggest change around an internal temperature of $70^{\circ}C$ and $80^{\circ}C$, respectively, while their cohesiveness showed the biggest change around $60^{\circ}C$ and $70^{\circ}C$, respectively. No significant difference was observed beyond those temperatures. The springiness of Hanwoo beef ER and CH shown began to increase significantly around an internal temperature of $70^{\circ}C$ and $80^{\circ}C$, respectively, while it began to decrease significantly around $90^{\circ}C$ (p<0.05). Hanwoo beef ER showed a faster change in its physical properties due to boiling compared to CH.