• Title/Summary/Keyword: direct adjustment

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A Study on the Design Guidelines of a Storage for Conservation of Relics in a Museum (문화재 보존을 위한 박물관 수장고의 공간계획 지침 연구)

  • Jung Sung-Wook
    • Korean Institute of Interior Design Journal
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    • v.15 no.3 s.56
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    • pp.144-154
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    • 2006
  • Except the time when relics of a museum are exhibited or loaned to the public, they are stored in a storage. In addition, it is common view that collections are exhibited a few of total stored collections in a museum. Therefore, the environmental condition of a storage is an important factor. Hereby, the purpose of this study is to suggest the design guidelines of a storage for conservation of relics in a museum. The results from this study are as follows briefly. First, location of storages has to be located and centralized above ground against preservation environment and additional renovation. Second, for storage size, It is reasonable to secure long-term experimental data after planning about 20% of whole section in present domestic situation. Third, in order to prevent environmental deterioration due to short storage floor space, adequate storage height has to be secured against a mezzanine deck and spare storages need to be planned. Where a mezzanine deck is designed, detailed plans have to be supported for equal micro climate in a storage. Fourth, in respect of environmental control of storages, finish materials with adjustment ability on relative humidity have to be used after the system is installed jointly direct and indirect way by air chamber, considering domestic condition for management of intermittent ventilation.

Modeling and Experimental Verification of ANN Based Online Stator Resistance Estimation in DTC-IM Drive

  • Reza, C.M.F.S.;Islam, Didarul;Mekhilef, Saad
    • Journal of Electrical Engineering and Technology
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    • v.9 no.2
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    • pp.550-558
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    • 2014
  • Direct Torque controlled induction motor (DTC-IM) drives use stator resistance of the motor for stator flux estimation. So, stator resistance estimation properly is very important for a stable and effective operation of the induction motor. Stator resistance variations because of changing in temperature make DTC operation difficult mainly at low speed. A method based on artificial neural network (ANN) to estimate the stator resistance online of IM for DTC drive is modeled and verified in this paper. To train the neural network a back propagation algorithm is used. Weight adjustment of neural network is done by back propagating the error signal between measured and estimated stator current. An extensive simulation has been carried out in MATLAB/SIMULINK to prove the efficacy of the proposed stator resistance estimator. The simulation & experimental result reveals that proposed method is able to obtain precise torque and flux control at low speed.

Analyses on the Factors Associated with Dietary Behavior Regarding Colon Cancer Risk (대장암 위험도와 관련된 식생활 행동 분석)

  • 오세영;이지현;김효종
    • Journal of Nutrition and Health
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    • v.37 no.3
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    • pp.202-209
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    • 2004
  • A case-control study was conducted in order to examine dietary behavioral factors associated with colorectal cancer risks. Data were collected from 128 cases with either colorectal cancer or large bowl adenomatous polyps and 129 controls regarding stages of dietary behavioral change, perceived barrier, self efficacy, nutrition knowledge, social support and food availability as well as body mass index and overall dietary quality. Cases showed less desirable behaviors with respect to fat reduction and vegetable intake compared with controls based on the analyses of the stages of dietary change. After adjustment of relevant covariates (age, gender and smoking), significant trends of increasing risk with higher level emerged for perceived barriers resulted from environmental conditions (OR = 1.6 - 2.0) and self-efficacy (OR = 2.2-2.3). No such relationships were found for nutrition knowledge and social support. The risk of colorectal cancer was associated with the kinds of foods available at home showing a borderline protective relation with milk (OR = 0.6) and respective significant and borderline direct associations for fresh meat (OR = 2.1) and soft drinks (OR = 0.6 when reversely scored). Within-group analyses presented best predictors of overall dietary quality as food availability for the case and self-efficacy and social support for the control. The findings of this study suggested a need for focusing on motivational and reinforcing factors in the development of nutrition education programs for colorectal cancer prevention.

A Structural Model of Self-Concept among Children and Adolescents from Multicultural Families Based on the Ecological Systems Model (다문화가정 아동·청소년 자아개념의 구조모형: 생태체계모형을 기반으로)

  • Oh, Eun Jin;Sung, Kyung Mi
    • Journal of East-West Nursing Research
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    • v.24 no.2
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    • pp.171-181
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    • 2018
  • Purpose: The study aimed to validate a structural model of self-concept among children and adolescents from multicultural families. Methods: Data were collected from 325 mothers of multicultural families and their 417 children. Confirmatory factor analysis, path analysis and multiple mediation analysis with a phantom variable approach were used to assess construct validity and relations between model variables. Results: Goodness of fit indices of the modified theoretical model, the standardized ${\chi}^2$ (2.75), RMR (.02), RMSEA (.07), NFI (.90), TLI (.92), CFI (.94), GFI (.89), and AGFI (.87), met criteria. Social support and mental health problem had significant direct effects on self-concept, whereas residential environment and school adjustment had significant indirect effects, accounting in combination for 53% of the variance in self-concept. Conclusion: Based on the results, mental health problem mediated the relationships of self-concept and parenting stress.

Mediating Effects of Hope and Therapeutic Relationship in the Relation between General Social Functions and Mental Health Recovery of Community People with Mental Illness (지역사회 정신장애인의 전반적 사회기능과 정신건강 회복 간의 관계에서 희망과 치료적 관계의 매개효과)

  • Shin, Sun Hwa;Hwang, Jung Hee
    • Research in Community and Public Health Nursing
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    • v.30 no.1
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    • pp.69-78
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    • 2019
  • Purpose: This study tries to test mediating effects of hope and therapeutic relationship in the relation between general social functions and mental health recovery of community people with mental illness. Methods: This study was carried out in a cross-sectional research design. The participants included 217 people with mental illnesses who were enrolled at eight Mental Health Welfare Centers in the Gyeonggi Province. Data were collected from February to May, 2018. The collected data were analyzed using a regression analysis, and SPSS PROCESS macro was used to test the mediating effects. Results: This study analyzed the direct effects of general social functions on the hope, therapeutic relationship and mental health recovery. And general social functions had indirect effects on their mental health recovery via hope and therapeutic relationship. Both hope and therapeutic relationship had dual mediating effects in the influence of general social functions on mental health recovery. Conclusion: The role of hope and therapeutic relationship in the mental health recovery of community people with mental illness is important, and it is confirmed that hope is a powerful factor influencing mental health recovery.

Does mini-implant-supported rapid maxillary expansion cause less root resorption than traditional approaches? A micro-computed tomography study

  • Alcin, Rukiye;Malkoc, Siddik
    • The korean journal of orthodontics
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    • v.51 no.4
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    • pp.241-249
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    • 2021
  • Objective: This study aimed to evaluate the volume, amount, and localization of root resorption in the maxillary first premolars using micro-computed tomography (micro-CT) after expansion with four different rapid maxillary expansion (RME) appliances. Methods: In total, 20 patients who required RME and extraction of the maxillary first premolars were recruited for this study. The patients were divided into four groups according to the appliance used: mini-implant-supported hybrid RME appliance, hyrax RME appliance, acrylic-bonded RME appliance, and full-coverage RME appliance. The same activation protocol (one activation daily) was implemented in all groups. For each group, the left and right maxillary first premolars were scanned using micro-CT, and each root were divided into six regions. Resorption craters in the six regions were analyzed using special CTAn software for direct volumetric measurements. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test with Bonferroni adjustment. Results: The hybrid expansion appliance resulted in the lowest volume of root resorption and the smallest number of craters (p < 0.001). In terms of overall root resorption, no significant difference was found among the other groups (p > 0.05). Resorption was greater on the buccal surface than on the lingual surface in all groups except the hybrid appliance group (p < 0.05). Conclusions: The findings of this study suggest that all expansion appliances cause root resorption, with resorption craters generally concentrated on the buccal surface. However, the mini-implant-supported hybrid RME appliance causes lesser root resorption than do other conventional appliances.

Econometric Analysis of the Determinants of Real Effective Exchange Rate in the Emerging ASEAN Countries

  • RAKSONG, Saranya;SOMBATTHIRA, Benchamaphorn
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.731-740
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    • 2021
  • This research aims to investigate the determinants of real effective exchange rate in emerging ASEAN countries, including Indonesia, Malaysia, Philippines, Thailand, and Vietnam. The research was conducted by using quarterly time series data set from 1980Q1 to 2020Q3. Cointegration and the error correction model (ECM) methods were applied to test the long run and short run relationship of the real effective exchange rate and its determinants. The results indicate that the ratio of foreign direct investment to GDP and the government spending have significantly positive impact on real effective exchange rate in the Emerging ASEAN countries. The trade opening had influencing real effective exchange rate in most the Emerging ASEAN countries, except Vietnam. In addition, the international reserve (INR) had significant long-run impacts variables on real effective exchange rate in Malaysia, Thailand and Vietnam. In the short run equilibrium, the error collection term suggest that Indonesia and Malaysia are the fastest speed adjustment to equilibrium. In addition, the term of trade influence the real effective exchange rate in Indonesia, Malaysia, and the Philippines but it is not in Thailand and Vietnam. However, FDI is a major factor of the real effective exchange rate in Vietnam, but not for other countries.

Evaluation of Strength Properties for Bolted Connections with Lumber from Small Diameter Logs

  • Park, Joo-Saeng;Park, Chun-Young;Chun, Su-Kyoung;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.3
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    • pp.59-65
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    • 2002
  • EYM (European Yield Model), which was adopted in NDS (National Design Specification for wood construction), has been used in Korea without any verification of the analysis of bolted wood connections. In the case of applying lumber from domestic small diameter logs, however, there are some problems with the direct application of EYM ; 1) relatively low dowel bearing strength and dimensional stability due to a large amount of immature wood, 2) effect of MC (moisture contents) on the dowel bearing strength of wood and the yield load of a bolted connection. To evaluate the strength properties of bolted connections with lumber from domestic small diameter logs, effect of MC on the dowel bearing strength of wood was investigated and double shear bolted connection tests were performed. As the MC of wood increased, the dowel bearing strength was linearly reduced, even under 19% MC, which showed that adjustment, not considered in NDS, was required. Double shear bolted connection tests indicated that effect of MC on yield load should be considered in order to determine design value.

Online Adaptation of Control Parameters with Safe Exploration by Control Barrier Function (제어 장벽함수를 이용한 안전한 행동 영역 탐색과 제어 매개변수의 실시간 적응)

  • Kim, Suyeong;Son, Hungsun
    • The Journal of Korea Robotics Society
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    • v.17 no.1
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    • pp.76-85
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    • 2022
  • One of the most fundamental challenges when designing controllers for dynamic systems is the adjustment of controller parameters. Usually the system model is used to get the initial controller, but eventually the controller parameters must be manually adjusted in the real system to achieve the best performance. To avoid this manual tuning step, data-driven methods such as machine learning were used. Recently, reinforcement learning became one alternative of this problem to be considered as an agent learns policies in large state space with trial-and-error Markov Decision Process (MDP) which is widely used in the field of robotics. However, on initial training step, as an agent tries to explore to the new state space with random action and acts directly on the controller parameters in real systems, MDP can lead the system safety-critical system failures. Therefore, the issue of 'safe exploration' became important. In this paper we meet 'safe exploration' condition with Control Barrier Function (CBF) which converts direct constraints on the state space to the implicit constraint of the control inputs. Given an initial low-performance controller, it automatically optimizes the parameters of the control law while ensuring safety by the CBF so that the agent can learn how to predict and control unknown and often stochastic environments. Simulation results on a quadrotor UAV indicate that the proposed method can safely optimize controller parameters quickly and automatically.

Determinants of Performance and Design for Improving Safety Helmet Usability (안전모 사용성 향상을 위한 성능 및 디자인 결정 요인에 관한 연구)

  • Sang Woo Shim;Yong Su Sim;Jong Bin Lee;Seong Rok Chang
    • Journal of the Korean Society of Safety
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    • v.38 no.3
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    • pp.85-92
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    • 2023
  • A safety helmet is considered the last gear to protect workers from harmful and dangerous events occurring on industrial sites. Recently, interest in the importance of personal protective equipment design reflecting individual characteristics has been emphasized to improve usability and convenience. However, it has been found that if it is inconvenient to wear or has poor work efficiency, it will not be used well or will be used incorrectly. In this study, an investigation was performed with 35 questions, direct observation, and intensive interviews of construction workers to determine the inconvenience and problems of wearing safety helmets. Moreover, managers of 9 construction sites in 6 cities were asked about the performance and design of safety helmets. As a positive answer, it was found that the brim (awning) of the safety helmet was shortened to give the safety glasses a light-shielding function. In addition, an upward adjustment all-in-one type safety helmet was requested. On the other hand, it was revealed that negative answers felt uncomfortable due to the brim (awning) on the front of the helmet. Based on the survey results, a new helmet model suitable for construction site activities was presented, and wearability improvement determinants were discovered through performance and design improvement.