• Title/Summary/Keyword: limitation

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Sonochemical Effects using Multi-stepped Ultrasonic Horn (다단 혼 형태의 초음파 장비를 이용한 초음파 화학적 효과 연구)

  • Choi, Jongbok;Lee, Seongeun;Son, Younggyu
    • Journal of Soil and Groundwater Environment
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    • v.25 no.4
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    • pp.58-66
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    • 2020
  • Since the typical horn-type ultrasonic equipment induces a reaction at the probe tip, the sonochemical reaction has a limitation that it occurs only in a specific area. As one of the ways to overcome this limitation, an ultrasonic device with multi-stepped horn equipped with several oscillators has been developed. The objective of this study was to investigate the sonochemical effects induced by acoustic cavitation system in 20 kHz multi-stepped ultrasonic horn using calorimetry, KI dosimetry and the luminol test. The sonochemical effects of multi-stepped ultrasonic horn were compared with that of the typical horn-type 20 kHz ultrasonic device. The effect of immersion depth and power on the sonochemical reaction was investigated in the ultrasonic system with multi-stepped ultrasonic horn. Higher calorimetric energy was obtained at higher immersion depth and power conditions. Sonochemical effects increased significantly when using the high immersion depth and input power. However, as the input power increased, the cavitation reaction zone concentrated around the ultrasonic horn. Additionally, the experiments to examine the effect of liquid temperature was conducted. The smaller sonochemical reaction was obtained for the higher liquid temperature. The effect on temperature seems to be closely related to liquid conditions such as viscosity and vapor pressure of water.

Choices of Medical Services and Burden of Health Care Costs: Japanese Prohibition of Mixed Treatment in Health Care (의료서비스 선택과 비급여 의료비 부담: 일본 혼합진료금지제도 고찰)

  • Oh, Eun-Hwan
    • Health Policy and Management
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    • v.31 no.1
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    • pp.17-23
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    • 2021
  • With the introduction of national health insurance, the burden of health care costs decreased and choices of medical services widened. However, because of the rapid expansion of non-covered medical services by health insurance, financial security for health care expenditure is still low. This gives patients barriers to choose medical services especially for non-covered medical services, and it becomes narrower. Compared to Korea, Japan has high financial protection in health care utilization, but there exists a limitation using covered and non-covered medical services both together. This is called a prohibition of mixed treatment in health care. This study reviews the Japanese health care system that limits choosing medical services and the burden of health care costs. The prohibition of mixed treatment can alleviate the out-of-pocket burden in the non-benefit sector, but it can be found that it has a huge limitation in that it places restrictions on choices for both healthcare professionals and patients.

Updates on the treatment of adhesive capsulitis with hydraulic distension

  • Jang Hyuk, Cho
    • Journal of Yeungnam Medical Science
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    • v.38 no.1
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    • pp.19-26
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    • 2021
  • Adhesive capsulitis of the shoulder joint is a common disease characterized by pain at the insertional area of the deltoid muscle and decreased range of motion. The pathophysiological process involves fibrous inflammation of the capsule and intraarticular adhesion of synovial folds leading to capsular thickening and contracture. Regarding the multidirectional limitation of motion, a limitation in external rotation is especially prominent, which is related to not only global fibrosis but also to a localized tightness of the anterior capsule. Ultrasound and magnetic resonance imaging studies can be applied to rule out other structural lesions in the diagnosis of adhesive capsulitis. Hydraulic distension of the shoulder joint capsule provides pain relief and an immediate improvement in range of motion by directly expanding the capsule along with the infusion of steroids. However, the optimal technique for hydraulic distension is still a matter of controversy, with regards to the infusion volume and rupture of the capsule. By monitoring the real-time pressure-volume profile during hydraulic distension, the largest possible fluid volume can be infused without rupturing the capsule. The improvement in clinical outcomes is shown to be greater in capsule-preserved hydraulic distension than in capsule-ruptured distension. Moreover, repeated distension is possible, which provides additional clinical improvement. Capsule-preserved hydraulic distension with maximal volume is suggested to be an efficacious treatment option for persistent adhesive capsulitis.

A Study on Improvement of Aeronautical Study System for Potential Obstacles in the Vicinity of Aerodromes (공항 주변 잠재적 장애물에 대한 항공학적 검토 제도 개선 연구)

  • Lee, Daekyum;Yun, Seokjae;Park, Bomi;Kim, Jechul;Kim, Jun-Hyuk
    • 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.

Bilateral Digital Extensor Hypoplasia Correction: A Case Report and Systematic Review

  • Marudeen Aivaz;Esperanza Mantilla-Rivas;Ashleigh Brennan;John Thomas;Elizabeth L. Malphrus;Monica Manrique;Albert K. Oh;Gary F. Rogers
    • Archives of Plastic Surgery
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    • v.50 no.2
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    • pp.177-181
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    • 2023
  • Digital extensor hypoplasia (DEH) is a rare malformation that presents with loss of active finger extension at the metacarpophalangeal (MCP) joints. Descriptions of optimal treatment and outcomes in this population are sparse. We describe successful operative treatment of a child with DEH involving the extensor digitorum communis, extensor digiti minimi, and the extensor indicis proprius tendons. The 5-year-old male patient was referred for severe limitation on bilateral finger extension since birth. He had been previously diagnosed with arthrogryposis and managed conservatively. Due to lack of improvement, magnetic resonance imaging was done evidencing hypoplasia/aplasia of the extensor tendons. The patient underwent successful tendon transfers using extensor carpi radialis longus to the common extensor tendons, and one hand required an additional tenolysis procedure. 2 years postoperatively, his MCP position and finger extension are markedly improved, and he is able to grip objects without limitation or difficulty. The patient returned to full activity without restriction.

Developing a Graph Convolutional Network-based Recommender System Using Explicit and Implicit Feedback (명시적 및 암시적 피드백을 활용한 그래프 컨볼루션 네트워크 기반 추천 시스템 개발)

  • Xinzhe Li;Dongeon Kim;Qinglong Li;Jaekyeong Kim
    • Journal of Information Technology Services
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    • v.22 no.1
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    • pp.43-56
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    • 2023
  • With the development of the e-commerce market, various types of products continue to be released. However, customers face an information overload problem in purchasing decision-making. Therefore, personalized recommendations have become an essential service in providing personalized products to customers. Recently, many studies on GCN-based recommender systems have been actively conducted. Such a methodology can address the limitation in disabling to effectively reflect the interaction between customer and product in the embedding process. However, previous studies mainly use implicit feedback data to conduct experiments. Although implicit feedback data improves the data scarcity problem, it cannot represent customers' preferences for specific products. Therefore, this study proposed a novel model combining explicit and implicit feedback to address such a limitation. This study treats the average ratings of customers and products as the features of customers and products and converts them into a high-dimensional feature vector. Then, this study combines ID embedding vectors and feature vectors in the embedding layer to learn the customer-product interaction effectively. To evaluate recommendation performance, this study used the MovieLens dataset to conduct various experiments. Experimental results showed the proposed model outperforms the state-of-the-art. Therefore, the proposed model in this study can provide an enhanced recommendation service for customers to address the information overload problem.

MULTI-APERTURE IMAGE PROCESSING USING DEEP LEARNING

  • GEONHO HWANG;CHANG HOON SONG;TAE KYUNG LEE;HOJUN NA;MYUNGJOO KANG
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.27 no.1
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    • pp.56-74
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    • 2023
  • In order to obtain practical and high-quality satellite images containing high-frequency components, a large aperture optical system is required, which has a limitation in that it greatly increases the payload weight. As an attempt to overcome the problem, many multi-aperture optical systems have been proposed, but in many cases, these optical systems do not include high-frequency components in all directions, and making such an high-quality image is an ill-posed problem. In this paper, we use deep learning to overcome the limitation. A deep learning model receives low-quality images as input, estimates the Point Spread Function, PSF, and combines them to output a single high-quality image. We model images obtained from three rectangular apertures arranged in a regular polygon shape. We also propose the Modulation Transfer Function Loss, MTF Loss, which can capture the high-frequency components of the images. We present qualitative and quantitative results obtained through experiments.

Exercise rehabilitation for recurrent extraocular muscle movement limitation after pediatric blowout fracture surgery: a case report

  • Jeong Do Park;Syeo Young Wee;Se Young Kim
    • Archives of Craniofacial Surgery
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    • v.24 no.3
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    • pp.133-138
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    • 2023
  • White-eyed blowout fractures with extraocular muscle (EOM) entrapment necessitate emergency surgical intervention. However, even after surgery, diplopia or EOM motion limitations may persist due to the incomplete reduction of soft tissue herniation caused by inadequate dissection or unresolved muscle strangulation. In this report, we present a case of postoperative EOM movement limitation in a 5-year-old girl who experienced recurrent restriction in the upward gaze of her right eye 14 days after surgery. Instead of revision surgery, the patient was treated with targeted EOM exercises focusing on the inferior rectus muscle and inferior oblique muscle. The patient was instructed to slowly move her pupils from the central point to the upper and outer sides, then in a straight line from the central point to the lower and inner sides before returning to the center point. On the 28th postoperative day, 2 weeks after initiating the exercises, the patient's EOM motion fully recovered. This case highlights the effectiveness of EOM exercises as a non-surgical treatment approach for improving recurrent EOM movement limitations in the absence of soft tissue herniation following surgical management of blowout fractures in children.

Recent Progress in Immunotherapy for Metastatic Colorectal Cancer (전이성 대장암에 대한 면역치료의 최신 지견)

  • Seong Jung Kim;Jun Lee
    • Journal of Digestive Cancer Research
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    • v.10 no.2
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    • pp.65-73
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    • 2022
  • A breakthrough in immunotherapy has changed the outlook for metastatic colorectal cancer (mCRC) treatment as the immune surveillance evasion mechanism of tumor cells has been continuously elucidated. Immune checkpoint inhibitors (ICI), such as pembrolizumab, nivolumab, and ipilimumab, which block immune checkpoint receptors or ligands have been approved for the treatment of mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) mCRC based on numerous clinical studies. However, 50% of dMMR/MSI-H mCRC and most mismatch repair proficient/microsatellite stable mCRC remained unresponsive to current immunotherapy. Clinical trials on combination therapy that adds various treatments, such as target agents, chemotherapy, or radiation therapy to ICI, have been actively conducted to overcome this immunotherapy limitation. Further studies on safety and efficacy are needed although several trials presented promising data. Additionally, dMMR/MSI-H, tumor mutation burden, and programmed cell death ligand-1 expression have been studied as biomarkers for predicting the treatment response to immunotherapy, but the discovery and validation of more sensitively predictable biomarkers remained necessary. Thus, this study aimed to review recent studies on immunotherapy in mCRC, summarize the efficacy and limitation of immunotherapy, and describe the biomarkers that predict treatment response.

Development of Control System for 2MW Direct Drive Wind Turbine (2MW급 직접구동형 풍력터빈 제어시스템 개발)

  • Moon, Jun-Mo;Jang, Jeong-Ik;Yoon, Kwang-Yong;Joe, Gwang-Myung;Lee, Kwon-Hee
    • Journal of Wind Energy
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    • v.2 no.1
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    • pp.90-96
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    • 2011
  • The purpose of this paper is to describe the control system for optimal performance of 2MW gearless PMSG wind turbine system, and to afford some techniques of the algorithm selection and design optimization of the wind turbine control system through analysis of load calculation and control characteristic. Wind turbine control system is composed of the main control system and remote control and monitoring system. The main control system is industrial PC based controller, and the remote control and monitoring system is a server based computer system. The main control system has a supervisory control of the wind turbine with operation procedures and power-speed control through the torque control by pitch angle. There are some applications to optimize the wind turbine system at the starting mode with increasing of rotor speed, and cut-in operating mode to prevent trundling cut-in and cut-out, a gain scheduling of pitch PID controller, torque scheduling and limitation of generation power by temperature limitation or remote command by remote control and monitoring system. Also, the server operation program of the remote control and monitoring system and the design of graphical display are described in this paper.