• International Journal of Control, Automation, and Systems
• /
• 제6권2호
• /
• pp.160-170
• /
• 2008

Temperature control of an enclosed thermal system which has many applications including Rapid Thermal Processing (RTP) of semiconductor wafers showed an input-constraint violation for nonlinear controllers due to inherent strong coupling between the elements [1]. In this paper, a constrained nonlinear optimal control design is developed, which accommodates input constraints using the linear algebraic equivalence of the nonlinear controllers, for the temperature control of an enclosed thermal process. First, it will be shown that design of nonlinear controllers is equivalent to solving a set of linear algebraic equations-the linear algebraic equivalence of nonlinear controllers (LAENC). Then an input-constrained nonlinear optimal controller is designed based on that LAENC using the constrained linear least squares method. Through numerical simulations, it is demonstrated that the proposed controller achieves the equivalent performances to the classical nonlinear controllers with less total energy consumption. Moreover, it generates the practical control solution, in other words, control solutions do not violate the input-constraints.

• International Journal of Precision Engineering and Manufacturing
• /
• 제6권4호
• /
• pp.21-25
• /
• 2005

In the dynamic analysis of a mechanism, if one or more of the components are flexible, then the simulation will not be accurate because of the violation of the rigid body assumption. Mode shapes are used to represent the dynamic behavior of an elastic structure. A modal synthesis method which uses a combination of normal modes, constraint modes, and attachment modes, was used to represent effectively the elastic deformation of a flexible multibody. Since the combination of these modes should be different for each type of connecting part, the modal synthesis method was studied for the various types of interconnecting joints. In addition, the analysis procedure for the flexible body was explained. A satellite system with flexible solar panels was chosen as an example to show the effectiveness of the proposed method.

• 공학교육연구
• /
• 제21권2호
• /
• pp.3-6
• /
• 2018

A few thermodynamics texts are commonly found to have unrealistic example problems in which the process violates the second law of thermodynamics. This error would result from presentation order in the text which introduces first the first law for cycles, systems, and control volumes and then the second law later. In the presentation order, the example problems deal only with the first law without telling whether the process violates the second law. To correct this erroneous situation, it could be recommended to present the first law and the second law successively so that both laws could be applied simultaneously to the given example problems.

• Journal of Information Processing Systems
• /
• 제15권1호
• /
• pp.169-180
• /
• 2019

Transmitting visual information over a broadcasting network is not only prone to a copyright violation but also is a forgery. Authenticating such information and protecting its authorship rights call for more advanced data encoding. To this end, electronic watermarking is often adopted to embed inscriptive signature in imaging data. Most existing watermarking methods while focusing on robustness against degradation remain lacking of measurement against security loophole in which the encrypting scheme once discovered may be recreated by an unauthorized party. This could reveal the underlying signature which may potentially be replaced or forged. This paper therefore proposes a novel digital watermarking scheme in temporal-frequency domain. Unlike other typical wavelet based watermarking, the proposed scheme employed the Lorenz chaotic map to specify embedding positions. Effectively making this is not only a formidable method to decrypt but also a stronger will against deterministic attacks. Simulation report herein highlights its strength to withstand spatial and frequent adulterations, e.g., lossy compression, filtering, zooming and noise.

• Journal of Medicine and Life Science
• /
• 제16권1호
• /
• pp.10-12
• /
• 2019

Medical disputes can always arise in the medical environment. We aimed to decrease the medical disputes by analysis for causes and results of cases of medical disputes. The cases of medical dispute were found on the homepage of the Supreme Court based on the judgment data which was searched using the keyword 'Jeju, Medical accident' and it was described as the area related to each medical accident. There was total of 13 cases related medical disputes in Jeju. The final states of the patients were different in each causes, but death accounted for 10 cases (76.92%), comatose state for one and disability for two respectively. The cases were 2 related with an injury from a fall. The major cause was violation of medical care obligation. Physician have to learn recent medical knowledge, have competence, and explain the detailed procedures and complications before the procedures dependent on patient autonomy.

• 한국기계가공학회지
• /
• 제20권2호
• /
• pp.72-79
• /
• 2021

The present paper aims to set forth a two-dimensional theory for the dynamics of plates that is valid over a large range of excitation. To construct a dynamic plate theory within the long-wavelength approximation, two dimensional-reduction procedures must be used for analyzing the low- and high-frequency behaviors under the dynamic variational-asymptotic method. Moreover, a separate and logically independent step for the short-wavelength regime is introduced into the present approach to avoid violation of the positive definiteness of the derived energy functional and to facilitate qualitative description of the three-dimensional dispersion curve in the short-wavelength regime. Two examples are presented to demonstrate the capabilities and accuracy of all of the formulas derived herein by using various dispersion curves through comparison with the three-dimensional finite element method.

• Clinics in Shoulder and Elbow
• /
• 제25권4호
• /
• pp.334-338
• /
• 2022

Currently, the literature contains few studies that describe any potential complications following arthroscopic acromioplasty. Because part of the anterior deltoid originates from the anterior acromion, there is a risk for violation and subsequent iatrogenic rupture or avulsion during this procedure. This type of injury can be a devastating problem for patients that may lead to poor function and debilitating pain. We present a patient with deltoid insufficiency following arthroscopic acromioplasty who elected to proceed with operative management with a planned arthroscopic evaluation of the shoulder followed by an open deltoid repair. At the final follow-up visit 2.5 years postoperatively, the patient reported improved pain from baseline and no residual disability and was able to perform most activities of daily living without difficulty. This case serves as an example of a surgical repair for a deltoid avulsion following arthroscopic acromioplasty. As there is still a lack of standard guidelines, our suture repair technique can be considered one method of treatment for this type of injury.

• Journal of Astronomy and Space Sciences
• /
• 제40권4호
• /
• pp.217-224
• /
• 2023

The Korea Pathfinder Lunar Orbiter (KPLO), also known as Danuri, successfully entered its mission orbit on December 27, 2022 (UTC), and is currently performing its mission smoothly. To mitigate potential contingencies during the flight and to navigate the spacecraft into the desired lunar orbit, the KPLO flight dynamics (FD) team analyzed major trajectory-related contingencies that could lead to the violation of mission requirements and prepared operational procedures from the perspective of trajectory and FD. This paper presents the process of preparing contingency trajectory operations for the KPLO, including the identification of trajectory contingencies, prioritization results, and the development of recovery plans and operational procedures. The prepared plans were successfully applied to address minor contingencies encountered during actual operations. The results of this study will provide valuable insights to FD engineers preparing for space exploration mission operations.

• 디지털융복합연구
• /
• 제14권11호
• /
• pp.37-44
• /
• 2016

본 연구는 청소년의 학교폭력 피해경험과 자아존중감의 관계에서 인권피해인식의 매개효과를 파악하는 데 연구 목적을 두었다. 이를 위해서 2015년 9월부터 11월까지 청소년 554명을 대상으로 경상북도 B군에서 설문조사를 수행하였다. 주요 연구 결과를 보면, 첫째, 청소년의 학교폭력 피해경험은 일반적 특성 중 학교급에 따라 차이를 보였고 인권피해인식은 읍,면 지역에 따라 차이를 보였으나 자아존중감은 일반적 특성에 따라 차이를 보이지 않았다. 둘째, 상관분석 결과 학교폭력 피해경험은 인권피해인식과 정적 상관관계를 보였고 자아존중감과는 부적 상관관계를 보였다. 셋째, 회귀분석 결과 학교폭력 피해경험과 자아존중감과의 관계에서 인권피해인식이 완전매개하였다. 끝으로 학교폭력과 인권침해로 자아존중감이 저하된 학생들을 위한 정책적 함의를 하였다.

• 아태비즈니스연구
• /
• 제11권2호
• /
• pp.119-132
• /
• 2020

Purpose - This study seeks to deepen our understanding of abusive supervision and its negative consequences on subordinates. Specifically, it examines the underlying psychological mechanism between abusive supervision and subordinates' work engagement, in particular with its focus on the mediational role of psychological contract breach. Design/methodology/approach - Following the two rounds of pilot interviews, this study collected and analyzed 182 survey data from one construction company and one hospital - the sectors in which abusive supervision is known to be frequent, with one-month interval to avoid common methods variances. Findings - We have two key findings. First, abusive supervision is negatively related to subordinates' work engagement. Second, the psychological contract violation mediates the relationship between abusive supervision and subordinates' work engagement. Research implications or Originality - This study enriches extant research on abusive supervision by deepening our understanding of the underlying mechanism in which abusive supervision causes negative outcomes. On a practical note, companies need further efforts to address abusive supervision, for example, by introducing sophisticated HR practices, including accessible grievance procedures and more serious disciplinary actions, and/or by offering leadership educations to supervisors.