• Title/Summary/Keyword: Internal loss

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Choice of recipient vessels in muscle-sparing transverse rectus abdominis myocutaneous flap breast reconstruction: A comparative study

  • Moon, Kyung-Chul;Lee, Jae-Min;Baek, Si-Ook;Jang, Seo-Yoon;Yoon, Eul-Sik;Lee, Byung-Il;Park, Seung-Ha
    • Archives of Plastic Surgery
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    • v.46 no.2
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    • pp.140-146
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    • 2019
  • Background Thoracodorsal vessels (TDVs) and internal mammary vessels (IMVs) have both been widely employed as recipient vessels for use in free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flaps. However, whether TDVs or IMVs are preferable as recipient vessels for autologous breast reconstruction with a free MS-TRAM flap remains controversial. The purpose of this study was to compare the clinical outcomes when TDVs were used as recipient vessels to those obtained when IMVs were used as recipient vessels for autologous breast reconstruction with a free MS-TRAM flap. Methods A retrospective matched-cohort study was performed. We retrospectively reviewed data collected from patients who underwent a free MS-TRAM flap for autologous breast reconstructions after mastectomy between March 2003 and June 2013. After a one-to-one matching using age, 100 autologous breast reconstructions were selected in this study. Of the 100 breast reconstructions, 50 flaps were anastomosed to TDVs and 50 to IMVs. Patient demographics and clinical outcomes including operation time, length of hospital stay, postoperative complications, and aesthetic score were compared between the two groups. Results No statistically significant differences were found between the two groups in patient demographics and clinical outcomes, including the complication rates and aesthetic scores. There were no major complications such as total or partial flap loss in either group. Conclusions The results of our study demonstrate that both TDVs and IMVs were safe and efficient as recipient vessels in terms of the complication rates and aesthetic outcomes.

Effect of the Reactive Power Compensation System on Performance Enhancement in a 900 MW Combined Cycle Power Plant (무효전력보상장치 설치가 900 MW 복합화력발전소의 성능향상에 미치는 효과)

  • Lee, Young Ok;Yoo, Hoseon
    • Plant Journal
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    • v.17 no.2
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    • pp.48-53
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    • 2021
  • In the case of a 900 MW combined cycle power plant, most of the load on the site is a rotating device and is operated at a low power factor, and the power factor decrease increases the reactive power, which causes the efficiency of the device to be consumed and unnecessary unnecessary power consumption. This study intends to present the results by installing and operating a reactive power compensation device that absorbs and removes reactive power, which is a solution to this problem, on a 6.9 kV on-board bus. As a result of application of this system, first, it was confirmed that the power factor of the rotating machine was improved to 0.22 and the load power in the house was reduced by 1.4%, and the thermal efficiency of the generator was increased by 0.1% and the power generation power by 810 kW. Next, it was confirmed that the cost of construction and operation can be reduced in the future due to economic feasibility, with a decrease of 200 million won/year in electricity loss compared to 1.5 billion won in investment, an increase of 1 billion won/year in sales, and a one-year capital recovery period.

Flow Characteristics in a Supersonic Combustor with a Configuration of a Cavity (초음속 연소기 내 공동 형상에 따른 유동 특성)

  • Yim, Geon Wook;Roh, Tae-Seong;Lee, Hyoung Jin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.25 no.2
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    • pp.1-11
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    • 2021
  • The cavity inside the combustor increases the mixing efficiency of fuel and air by inducing a oscillation of the flow and the recirculation area with a low speed, and enables continuous combustion by maintaining the flame. In this study, the characteristics of the internal flow by change in the shape parameters of the cavity were analyzed through experiments and two-dimensional computational analysis. It was observed that the flow in the supersonic combustor was greatly influenced by various shape parameters of cavity besides L/D. Even with the same L/D, it was confirmed that the flow type varies depending on the depth of the cavity, either open or closed type, and the aft ramp angle of the cavity and the height of the combustor also affect the flow characteristics. As a result, the change in the shape parameters of the cavity had a great influence on the total pressure loss.

Culturable Endophytes Associated with Soybean Seeds and Their Potential for Suppressing Seed-Borne Pathogens

  • Kim, Jiwon;Roy, Mehwish;Ahn, Sung-Ho;Shanmugam, Gnanendra;Yang, Ji Sun;Jung, Ho Won;Jeon, Junhyun
    • The Plant Pathology Journal
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    • v.38 no.4
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    • pp.313-322
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    • 2022
  • Seed-borne pathogens in crops reduce the seed germination rate and hamper seedling growth, leading to significant yield loss. Due to the growing concerns about environmental damage and the development of resistance to agrochemicals among pathogen populations, there is a strong demand for eco-friendly alternatives to synthetic chemicals in agriculture. It has been well established during the last few decades that plant seeds harbor diverse microbes, some of which are vertically transmitted and important for plant health and productivity. In this study, we isolated culturable endophytic bacteria and fungi from soybean seeds and evaluated their antagonistic activities against common bacterial and fungal seed-borne pathogens of soybean. A total of 87 bacterial isolates and 66 fungal isolates were obtained. Sequencing of 16S rDNA and internal transcribed spacer amplicon showed that these isolates correspond to 30 and 15 different species of bacteria and fungi, respectively. Our antibacterial and antifungal activity assay showed that four fungal species and nine bacterial species have the potential to suppress the growth of at least one seed-borne pathogen tested in the study. Among them, Pseudomonas koreensis appears to have strong antagonistic activities across all the pathogens. Our collection of soybean seed endophytes would be a valuable resource not only for studying biology and ecology of seed endophytes but also for practical deployment of seed endophytes toward crop protection.

A Study on the Internal Flow Analysis of High-pressure Shut-off Valve for CNG Charging Station Piping System (CNG 충전소 배관시스템용 고압 차단밸브에 대한 내부 유동해석에 관한 연구)

  • Chin, Do-Hun
    • Journal of the Korean Society of Industry Convergence
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    • v.24 no.6_2
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    • pp.773-779
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    • 2021
  • CNG, which has recently been attracting attention as an alternative fuel in the transportation field to reduce emissions caused by global warming, is natural gas with abundant reserves and mainly composed of methane. Being in a gaseous state, natural gas requires the compression and liquefaction processes for transportation. Until now, general shut-off valves for liquid and gas piping have been developed in Korea, but there are few studies on shut-off valves for high pressures of about 200 bar. Currently, research on the flow analysis of valves is being actively conducted around the world. However, there are relatively many studies on large valves such as low-pressure valves or shipbuilding and marine, and the safety factor through structural analysis to check the structural integrity of the valve is checked at the design stage. Since it is necessary to have a fast response speed while minimizing pressure and speed loss due to flow change, basic research was conducted on the flow analysis of the valve to secure design data, and the numerical analysis was performed on high-pressure automatic shut-off valves applied to CNG refueling stations. After securing the basic valve shape through reverse engineering for advanced products, we compared the valve flow coefficient Cv coefficient with advanced products. As a result, it was found that the reverse engineering model was at the level of about 60%. However, we compared the Cv coefficient by modifying the reverse engineering model, and the result showed that it was improved to about 96%.

Analysis of Psychological Factors Inducing Cybercrime (사이버범죄를 유발하는 심리적요인 분석)

  • Lim, HeonWook
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.2
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    • pp.157-163
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    • 2021
  • This study attempted to find individual reasons for inducing cybercrime. The survey was conducted targeting investigators and security experts on 11 types of cybercrime. There are 16 internal factors that cause crime and classified according to Maslow's 5 steps. As a result of the survey on a total of 176 items, the credibility of the Cronbach's Alpha coefficient was 0.925. The result of the factor analysis is as follows. Factor analysis results are maslow phase 1 physiological desire is commercial, sykes. Phase 2 safety desires are not punishable and crowd. The three-stage social desire is impulsiveness, indifference, etc. The fourth stage of respect is anonymity and honor. The desire for self-reality in stage 5 has been reduced to indesity, a loss of moderation, morality, and media effects. In conclusion, the physiological desire, the desire for respect for the crime of infringing on the information and communication network, the desire for menstruation, the desire for self-realization for the crime of using information and communication networks, the desire for self-actualization for the crime of illegal content. It was in the order of desire.

The Development of a Tool for Assessment of Spiritual Distress in Cancer Patients (암 환자의 영적 디스트레스 측정도구 개발)

  • Kim, Jin Sook;Ko, Il-Sun;Koh, Su Jin
    • Journal of Korean Academy of Nursing
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    • v.52 no.1
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    • pp.52-65
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    • 2022
  • Purpose: This study was conducted to develop a scale to measure spiritual distress in cancer patients. Methods: A total of 69 preliminary items for the spiritaul distress assessment tool (SDAT) were compiled, based on a literature review, selection of empirically relevant items through concept analysis of hybrid models, confirmation of content validity by experts, cognitive interviews, and a pretest. Self-administered questionnaires were collected between April 1 and July 31, 2018, from 225 cancer patients at four medical institutions and one nursing home. The data were analyzed using item analysis, exploratory factor analysis, convergent and discriminant validity, and Pearson correlation for criterion validity. Reliability was tested by Cronbash's α coefficient. Results: The final version of the SDAT consisted of 20 items. Five-factors, loss of peace, burden of family, avoidance of confronting death, guilt and remorse, regret for not being able to apololgize and forgive were extracted, and showed 62.8% of total variance. The factors were confirmed through convergent and discriminant validity. Criterion validity was confirmed by functional assessment chronic illness therapy spiritual well-being scale 12 (FACIT-Sp12). The overall Cronbach's α was .91, and the coefficients of each subscale ranged from .78~.83. Conclusion: The SDAT for cancer patients is valid and reliable. It is suggested that the tool can be used to measure spiritual distress in cancer patients.

Implant selection for successful reverse total shoulder arthroplasty

  • Joo Han Oh;Hyeon Jang Jeong;Yoo-Sun Won
    • Clinics in Shoulder and Elbow
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    • v.26 no.1
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    • pp.93-106
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    • 2023
  • Reverse total shoulder arthroplasty (RTSA) emerged as a new concept of arthroplasty that does not restore normal anatomy but does restore function. It enables the function of the torn rotator cuff to be performed by the deltoid and shows encouraging clinical outcomes. Since its introduction, various modifications have been designed to improve the outcome of the RTSA. From the original cemented baseplate with peg or keel, a cementless baseplate was designed that could be fixed with central and peripheral screws. In addition, a modular-type glenoid component enabled easier revision options. For the humeral component, the initial design was an inlay type of long stem with cemented fixation. However, loss of bone stock from the cemented stem hindered revision surgery. Therefore, a cementless design was introduced with a firm metaphyseal fixation. Furthermore, to prevent complications such as scapular notching, the concept of lateralization emerged. Lateralization helped to maintain normal shoulder contour and better rotator cuff function for improved external/internal rotation power, but excessive lateralization yielded problems such as subacromial notching. Therefore, for patients with pseudoparalysis or with risk of subacromial notching, a medial eccentric tray option can be used for distalization and reduced lateralization of the center of rotation. In summary, it is important that surgeons understand the characteristics of each implant in the various options for RTSA. Furthermore, through preoperative evaluation of patients, surgeons can choose the implant option that will lead to the best outcomes after RTSA.

Energy-dispersive X-ray spectroscopic investigation of a fractured non-submerged dental implant associated with abutment fracture

  • Truc Thi Hoang Nguyen;Mi Young Eo;Kezia Rachellea Mustakim;Mi Hyun Seo;Hoon Myoung;Soung Min Kim
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.49 no.1
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    • pp.43-48
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    • 2023
  • The biocompatibility and durability of implant fixtures are major concerns for dentists and patients. Mechanical complications of the implant include abutment screw loosening, screw fracture, loss of implant prostheses, and implant fracture. This case report aims to describe management of a case of fixture damage that occurred after screw fracture in a tissue level, internal connection implant and microscopic evaluation of the fractured fixture. A trephine bur was used to remove the fixture, and the socket was grafted using allogeneic bone material. The failed implant was examined by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), which revealed a fractured fixture with both normal and irregular bone patterns. The SEM and EDS results give an enlightenment of the failed fixture surface micromorphology with microfracture and contaminated chemical compositions. Noticeably, the significantly high level of gold (Au) on the implant surface and the trace amounts of Au and titanium (Ti) in the bone tissue were recorded, which might have resulted from instability and micro-movement of the implant-abutment connection over an extended period of time. Further study with larger number of patient and different types of implants is needed for further conclusion.

A Design of SSD Dedicated RAID System for Efficient Resource Management (효율적인 자원관리를 위한 SSD 전용 RAID 시스템 설계)

  • Hyun-Seob Lee
    • Journal of Internet of Things and Convergence
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    • v.10 no.2
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    • pp.109-114
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    • 2024
  • Enterprise storage systems that require high data reliability are applying RAID (Redundant Array of Independent Disks) systems to recover from data loss and failure. In particular, RAID 5 ensures space efficiency and reliability by distributing parity across multiple storage devices. However, when storage devices have different capacities, RAID is built based on the smallest capacity storage device, resulting in wasted storage space. Therefore, research is needed to solve this resource management problem. In this paper, we propose a method for RAID grouping of each independent NAND flash memory block in a RAID consisting of SSD (Solid State Disk) with external SSDs as well as internal SSDs. This method is divided into a policy for delivering block information inside SSDs to the RAID system and a policy for RAID grouping of physical addresses delivered from the RAID system. This method allows us to maintain a RAID that does not waste resources when SSDs of different capacities are grouped into RAID5. Finally, we demonstrate the effectiveness of the proposed method through experiments.