• Title/Summary/Keyword: effective modification method

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Cross Finger Flap with Reduction Pulp Plasty and Full Thickness Skin Graft (수질부 축소술과 전층 피부이식술을 이용한 교차수지 피판술)

  • Cho, Yong Hyun;Roh, Si Gyun;Lee, Nae Ho;Yang, Kyung Moo
    • Archives of Plastic Surgery
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    • v.36 no.5
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    • pp.674-677
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    • 2009
  • Purpose: Typical cross finger flap is still a good method for reconstruction of fingertip injuries. However, it is necessarily followed by great loss and aesthetically unpreferable result of donor finger. Hereby, we introduce a modification of cross finger flap with reduction pulp plasty and full thickness skin graft, with which we could reduce the defect size of injured fingertip and donor site morbidity at the same time, without any need for harvesting additional skin from other part of hand. Method: This method was performed in the patients with fingertip injuries of complete amputation or in case of loss of fingertip due to necrosis after replantation. Firstly, reduction pulp plasty was performed on the injured finger to reduce the size of defect of fingertip. Additional skin flap was obtained from the pulp plasty. Secondly, cross finger flap was elevated from the adjacent finger to cover the defect on the injured finger. At the same time, defect on the donor finger produced by the flap elevation was covered by full thickness skin graft with the skin obtained from the pulp plasty of injured finger. Results: Flap and graft survived without any necrosis after surgical delay and flap detachment. All of them were healed well and did not present any severe adversary symptoms. Conclusion: Cross finger flap with reduction pulp plasty and full thickness skin graft is an effective method that we can easily apply in reconstruction of fingertip injury. We think that it is more helpful than the usual manner, especially in cases of children with less soft tissue on their fingers for preservation and reduction of the morbidity of donor finger.

Optimal Design Method of Dynamic Vibration Absorber to Reduce Resonant Vibration Response of Ship Local Structure (선박 국부구조의 공진응답 저감을 위한 동흡진기 최적 설계 방법)

  • Kwon, Hyuk;Cho, Daeseung
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.3
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    • pp.134-140
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    • 2022
  • Ship local structure sometimes experiences severe vibration due to the resonance with an excitation force generated by the propulsion system. In that case, the installation of dynamic vibration absorber such as Tuned Mass Damper (TMD) on the structure can be considered as an effective alternative countermeasure to reduce the troublesome vibration if structural modification or change of excitation frequencies is difficult. Meanwhile, the conventional optimal design method of TMD premises the target structure exposed on an excitation force without the constraint of its magnitude and frequency range. However, the frequencies of major ship excitation forces due to propulsion system are normally bounded and its magnitude is varied according to its operation speed. Hence, the optimal design of TMD to reduce the resonant vibration of ship local structure should be differently approached compared with the conventional ones. For the purpose, this paper proposes an optimal design method of TMD considering maximum frequency and magnitude variation of a target harmonic excitation component. It is done by both lowering the resonant response at the 1st natural frequency and locating the 2nd natural frequency over maximum excitation frequency for the idealized 2 degree of freedom system consisted of the structure and the TMD. For the validation of the proposed method, a numerical design case of TMD for a ship local structure exposed on resonant vibration due to a propeller excitation force is introduced and its performance is compared with the conventionally designed one.

Synthesis and Non-Isothermal Crystallization Behaviors of Maleic Anhydride onto High Density Polyethylene

  • Ahn, Youngjun;Jeon, Jong Hyuk;Baek, Chul Seoung;Yu, Young Hwan;Thenepalli, Thriveni;Ahn, Ji Whan;Han, Choon
    • Journal of the Korean Ceramic Society
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    • v.53 no.1
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    • pp.24-33
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    • 2016
  • The grafting reaction for maleic anhydride (MA) onto high density polyethylene (HDPE) was investigated from solution process with initiators. The chemical modification of neat HDPE was carried out with various contents of MA (3-21 wt.%) and initiator (0.2-1 wt.%) at different temperature ($80-130^{\circ}C$). The grafting degree was obtained from the titration and the highest grafting degree was 3.1%. The grafting degree increased as the content of MA and initiator increased, however, the highest grafting degree was demonstrated for a particular content of MA and initiator. In the non-isothermal crystallization kinetics, the Ozawa model was unsuitable method to investigate the crystallization behavior of MA onto HDPE, whereas the Avrami and Liu models found effective. The crystallization rate was accelerated as the cooling rate increased, but postponed by combination of MA onto neat HDPE backbone.

Effects of Obesity Management Program for Obese Elementary School Children (비만아동에 대한 비만관리프로그램의 효과)

  • Kim, Hee-Kyung;Lee, Hyun-Ju
    • Child Health Nursing Research
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    • v.12 no.4
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    • pp.451-461
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    • 2006
  • Purpose: The purpose of this study was to identify the effects of a obesity management program on BMI, body composition, knowledge, perception and attitudes, mood and exercise habits in obese elementary school children with the goal of developing nursing interventions to promote a healthy lifestyle. Method: The study used a pre-experimental design with a one-group pre-post test. The content of the 8-week obesity management program included obesity education, diet control education, behavioral modification education, counseling, hand-reflexo massage, and exercise. Participants were 36 obese children who were students in elementary schools in K city. Data collection was done from October $4^{th}$ to November $28^{th}$, 2005. The data was analyzed using descriptive statistics and paired t-test. Results: After the students received the obesity management program, their BMI scores were significantly lowered, and scores for mood and excercise habits were significantly improved. Conclusion: The results show this obesity management program is effective in changing the BMI, mood, and behavioral modifications in obese students. The results suggest that this program be utilized to manage obesity in obese children, and that this study be replicated to compare an experimental group with a control group in order to verify the effects of the obesity management program.

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Pressure Fluctuations on Tapered and Setback Tall Buildings (비정형 초고층 건물의 변동 풍압)

  • Kim, Yong-Chul;Kanda, Jun;Tamura, Yukio;Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.13 no.1
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    • pp.97-104
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    • 2013
  • Recent tall buildings tend to have unconventional shapes as a prevailing, which is effective for suppressing across-wind responses. Suppression of across-wind responses is a major factor in tall building projects, and the so called aerodynamic modification method is comprehensively used. The purpose of the present study is to investigate the pressure fluctuations on tapered and setback tall buildings, including peak pressures, power spectra and coherences through the synchronous multi-pressure sensing system techniques. And flow measurements around the models were conducted to investigate the condition of vortex shedding. The results show that by tapering and setback, different distributions of mean pressure coefficients at leeward surface were found, which is caused by the geometric characteristics of the models. And the power spectra of wind pressures at sideward surface become wideband and the peak frequencies are different depending on heights, which makes the correlation near the Strouhal component low or even negative. The differences in shedding frequencies were also confirmed by the flow fields around the models.

A Study on Optimal Design of Panel Shape of a Body Structure for Reduction of Interior Noise

  • Kim, Hyo-Sig;Yoon, Seong-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.694-698
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    • 2006
  • This paper presents an optimal design process using beads on a body panel to improve interior noise of a passenger vehicle. Except modification of structural members, it is difficult to find effective countermeasures that can work for the intermediate frequency range from 100 Hz to 300 Hz which lies between the booming and low medium frequency. In this study, it is a major goal to find additional counter-measures for this intermediate frequency range by performing optimal design of beads on body panels. The proposed method for design optimization consists of 4 sub-steps, that is, a) problem definition, b) cause analysis, c) countermeasure development and d) validation. The objective function is minimization of interior noise level. The major design variables are the geometrical shape of a bead and combination of beads on the critical panels. Sensitivity analysis and optimization are performed according to the predefined process for an optimal design. It is verified that the proposed design decreases the level of noise transfer function above 5 dB.

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A Study on the Traffic Agent for Overlay Multicast (오버레이 멀티캐스트에서의 트래픽 에이전트에 관한 고찰)

  • Ko Joo-Young;Shim Jae-Chang;Kim Hyun-Ki
    • The KIPS Transactions:PartB
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    • v.12B no.6 s.102
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    • pp.685-690
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    • 2005
  • Recently, studies for effective multimedia data delivery have been widely performed. Among those researches, internet broadcasting is a technology to transmit various multimedia contents to variety of costumers on the internet simultaneously. To deliver large scale multimedia data such as internet broadcasting, efficient data delivery method is required. Therefore, technologies based on the overlay multicast of application larger multicast application are actively studied as an alternative for multicast overcoming shortcoming of uni-cast based technologies, which we one to one transmission methods. In this paper, we classify and study on the overlay multicasting for internet broadcasting, which can be implemented by application programs without modification in physical layer of the internet.

An analysis of vulnerability and the method to secure on Android SNS applications from alteration of the code segments (안드로이드 기반 SNS 어플리케이션의 코드 변조를 통한 취약점 분석 및 보안 기법 연구)

  • Lee, Sang Ho;Ju, Da Young
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.23 no.2
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    • pp.213-221
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    • 2013
  • According to the rapid growth of the number of SNS(Social Networking Service) applications based on Android OS, the importance of its security is also raised. Especially, many applications using KaKaoTalk platform has been released in these days, and these are top ranked in the relative markets. However, security issues on SNS applications have not been resolved clearly. Therefore, it is crucial to provide means to cope with the security threats posed by code-segment modification in the development stage of Android OS based SNS applications. In this paper, we analyze the security threats by modifying SNS application code segments and suggest effective security techniques.

A Study on Flame Monitoring System Development for Combustion Management of Boilers (보일러 연소관리를 위한 화염감시 시스템 개발에 관한 연구)

  • Baek, Woon-Bo;Shin, Jin-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.11
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    • pp.1587-1594
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    • 2003
  • Increased energy costs have placed demands for improved combustion efficiency, high equipment availability, low maintenance and safe operation. Furthermore low NO$_x\$ modification, installed due to strict environmental legislation, requires very careful combustion management. The flame monitoring system has been developed specially to satisfy these requirements. We aimed at gaining the relationship between the burner flame image and emissions such as NO$_x$ and unburned carbon in furnace by utilizing the image processing method. For the first step of development, its possibility test was undertaken with bench furnace. The test proceeded to the second step with pilot furnace and the system was observed to be effective for evaluating the combustion conditions. By using this technology, it is possible to perform continuous monitoring of the combustion conditions and instant detection of individual changes for each burner to prevent future loss of ignition. This may contribute to the saving of burner adjusting times for the changes of loads and fuels and to the reduction of the slagging as well.

Aerodynamic design optimization of an aircraft wing for drag reduction using computational fluid dynamics approach

  • Shiva, Kumar M.R;Srinath, R;Vigneshwar, K;Ravi, Kumar B
    • Wind and Structures
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    • v.31 no.1
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    • pp.15-20
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    • 2020
  • The aircraft industry supports aviation by building aircraft and manufacturing aircraft parts for their maintenance. Fuel economization is one of the biggest concerns in the aircraft industry. The reduction in specific fuel consumption of aircraft can be achieved by a variety of means, simplest and more effective is the one to impose minor modifications in the aircraft main wing or the parts which are exposed to the air flow. This method can lead to a reduction in aerodynamic resistance offered by the air and have a smoother flight. The main objective of this study is to propose geometric design modifications on an existing aircraft wing which acts as a vortex generator and it can reduce the drag and increase lift to drag ratio, leading to lower fuel consumption. The NACA 2412 aircraft wing is modified and designed. Rigorous flow analysis is carried out using computational fluid dynamics based software Ansys Fluent. Results show that saw tooth modification to the main wing shows the best aerodynamic efficiency as compared to other modifications.