• Title/Summary/Keyword: Members

Search Result 11,902, Processing Time 0.036 seconds

Patterns of Resistographs for Evaluating Deteriorated Structural Wood Members

  • LEE, Jun Jae;KIM, Kwang Chul;BAE, Mun Sung
    • Journal of the Korean Wood Science and Technology
    • /
    • v.31 no.6
    • /
    • pp.45-54
    • /
    • 2003
  • The density and strength of wood is affected by degradations and defects, such as voids and knots. Old wooden structures such as traditional cultural properties have been deteriorated by these types of defects. They were evaluated by a visual observation that is difficult to evaluate the inner deterioration in structures. In this study, three nondestructive testing techniques were investigated to detect the wooden structural members. Ultrasonic stress wave tests, drilling resistance tests and visual inspections were used to examine the structural wood members. Patterns of Resistograph using by drilling resistance tests could indicate the features of internal wood such as voids, knots, decay, fungi, and so on. The technique just like as ultrasonic stress wave tests, however, difficult to detect exactly area where small amounts of internal deterioration in logs are. In spite of results of ultrasonic stress wave test, the internal deterioration of wooden structural members could be evaluated by the relationship between ultrasonic stress wave tests and drilling resistance tests.

Cold-formed austenitic stainless steel SHS brace members under cyclic loading: Finite element modelling, design considerations

  • YongHyun Cho;Fangying Wang;TaeSoo Kim
    • Steel and Composite Structures
    • /
    • v.47 no.1
    • /
    • pp.135-145
    • /
    • 2023
  • This study presents a numerical investigation into the hysteretic behavior of cold-formed austenitic stainless steel square hollow section (SHS) brace members using a commercial finite element (FE) analysis software ABAQUS/Standard. The initial/post buckling and fracture life of SHS brace members are comprehensively investigated through parametric studies with FE models incorporating ductile fracture model, which is validated against the existing laboratory test results collected from the literature. It is found that the current predictive models are applicable for the initial buckling strengths of SHS brace members under cyclic loading, while result in significant inaccuracy in predictions for the post-buckling strength and fracture life. The modified predictive model is therefore proposed and the applicability was then confirmed through excellent comparisons with test results for cold-formed austenitic stainless SHS brace members.

A Study on Robotic-Laser-Welding Performance for Application of Non-Standard Steel Curtain Wall Members (비규격 스틸커튼월 부재의 적용을 위한 로봇 레이저용접 성능에 관한 연구)

  • Na, Sangho;Lee, JangHyun;Park, YoungMi;Kim, SungJin
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2021.11a
    • /
    • pp.4-5
    • /
    • 2021
  • In irregular curtain walls, the nominal stress required for each member varies greatly depending on the shape, so it is inefficient to design members based on the maximum required stress. Then, built-up members are absolutely necessary, but built-up members manufactured by Manpower-welding cannot be constructed in an irregular curtain wall building because it' not precise. In order to address the problems, this paper presents why Robotic-laser-welding should be used in irregular curtain walls using Gwanggyo Galleria Department Store involving 3D printing as an example. Results verify the performance of Robot-Laser-Welding as an efficient solution for precise steel curtain wall members.

  • PDF

A Basic Study of Crane Trajectory Distance Calculation for Sustainable PC Members Erection of Large Logistic Building (대형물류센터 PC부재 양중을 위한 크레인 궤적거리 산정 기초 연구)

  • Lim, Jeeyoung;Oh, Jinhyuk;Kim, Sunkuk
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2023.05a
    • /
    • pp.77-78
    • /
    • 2023
  • As large logistics buildings have high floor heights and long spans, these buildings are designed as PC structures, and large cranes are used to lift PC members. PC erection planning can generally cause errors depending on the field engineer's experience. To solve this problem, a basic analysis method is needed to establish a systematic PC member erection plan. Crane work can be minimized if the trajectory is easily and quickly calculated according to the location of the crane and applied to the site. Therefore, the objective of this study is a basic study of crane trajectory distance calculation for sustainable PC members erection of large logistic building. In this study, a crawler crane commonly used for lifting PC members is limited. The trajectory distance for the PC erection plan was automatically calculated using the algorithm.

  • PDF

M to mid-L type members of nearby young moving groups from Gaia EDR3

  • Lee, Jinhee;Song, Inseok;Murphy, Simon J.
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.46 no.2
    • /
    • pp.49.3-50
    • /
    • 2021
  • In this study, we aim to identify low-mass members of nearby, young stellar moving groups (NYMGs) from Gaia EDR3. The spatio-kinematic membership probabilities of the NYMGs were calculated utilizing the Bayesian membership probability calculation tool developed in our previous study. The youth of these spatio-kinematic members were assessed using positions on color-magnitude diagrams. We identified ~2200 new low-mass NYMG candidate members, that can be confirmed by follow-up spectroscopic observations. We performed pilot spectroscopic observation with WiFeS at Siding Spring Observatory observing 79 candidates, and about 80 per cent of them were confirmed as members.

  • PDF

Digital Transformation Requirements at Saudi Universities from Faculty Members' Perspectives

  • Taha Mansor Khawaji
    • International Journal of Computer Science & Network Security
    • /
    • v.23 no.11
    • /
    • pp.8-20
    • /
    • 2023
  • The current study aims to determine digital transformation (organizational, technical, and human resources) requirements at Saudi universities from Umm Al-Qura University faculty members' perspectives. The researcher used a quantitative approach based on the descriptive analytical design. To answer the questions of the study, the researcher used the questionnaire as a data collection tool. The questionnaire was sent electronically to faculty members working in colleges and institutes affiliated with Umm Al-Qura University in Makkah Al-Mukarramah, Saudi Arabia. The questionnaire consisted of the three dimensions of digital transformation: organizational; technical; and human resources requirements. The results showed that requirements related to human resources came first with an average of 2.25 then the organizational requirements with an average of 1.95, and in the last, technical requirements came with an average of 1.64. In addition, some suggestions were given by the participants (faculty members) related to the mechanism that could contribute to implementing digital transformation at Saudi universities. Likewise, at the end of the study, the researcher has given some suggestions related to the implementation of digital transformation requirements at Saudi universities.

A Study on Dimension of Structural Members and Calculating Standards of Choikgong (初翼工) Architecture (초익공집 주요 구조부재 단면치수 계획과 산출기준 연구)

  • Kim, Jong-Hoon;Kim, Wang-Jik
    • Journal of architectural history
    • /
    • v.20 no.4
    • /
    • pp.81-94
    • /
    • 2011
  • The purpose of the study, approaching from the aspect of the construction technologies, is to determine the architectural techniques of traditional wood architects in existence, through which the systems and techniques that create the inherent characteristics of Korean architecture are clarified. With understanding traditional construction system and focusing on the fact that built environment results from the consistent standards and technologies of architects, this study inquires into the systematic standard and its formation that present in the process of planning for the overall scale and shape of a building from the study determines dimension of structural members. All the members that constitute the structure are trimmed in advance and assembled in a short period of time on the site. Because of that, the dimensions for trimming and assembling are predetermined according to designated standards in the planning process, therefore consistent standard of computation are in necessity to design shapes and sizes of enormous amount of structural members. This study also shows the standards of measurement employed by architects while planning for structural members of a building, and how the size and range of its composition are developed.

Perception and Attitude of Emergency Medical Staff to Family Presence During Cardiopulmonary Resuscitation (심폐소생술 시 가족 입회에 대한 응급의료센터 의료인의 태도와 인식)

  • Koo, Hyun-Jung;Yoo, Yang-Sook
    • Korean Journal of Adult Nursing
    • /
    • v.23 no.6
    • /
    • pp.624-632
    • /
    • 2011
  • Purpose: This study was performed to determine the perception and attitude of emergency medical staff by the presence of family members while performing Cardiopulmonary Resuscitation (CPR). Methods: Data were collected from June and August in 2010 using questionnaire. The participants were 187 doctors and nurses who were working at emergency medical centers located at eight hospitals. Results: Approximately half of the medical emergency staff had previous experience of having requests from a patient's family members to remain present at the time of performing CPR. Most of the subjects did not know that the 2005 American Heart Association (AHA) guideline recommended including willing family members' during CPR. Doctors were more likely than nurses to recognize that the positive effects of family members being present during CPR. Conclusion: This study indicates that health professionals are not aware of the AHA guidelines for including family members during CPR of a patient and further that more doctors than nurses recognized the value of including willing family members during CPR.

Collaborative Relationship Analysis between Members of Apartment Construction Organizations

  • Kim, Jae-Yeob
    • Journal of the Korea Institute of Building Construction
    • /
    • v.14 no.1
    • /
    • pp.102-109
    • /
    • 2014
  • The purpose of this study is to analyze collaborative relationship between members of a building construction organization. For the analysis of collaborative relationship, this researcher collected data by conducting a questionnaire survey with members of three large building construction organizations for apartment housing. The analyzed contents of collaborative relationship were the 'frequency of communication between organizational members' and their 'reliability'. According to the analysis of communication network, construction managers had low frequency of communication, whereas those responsible for each area, like construction deputy managers, had high frequency of communication. It indicates that middle managers are at the center of communication related to construction work in construction organizations. According to the analysis of reliability network, construction managers showed highest reliability, and employees at the top level in an organizational map also showed high reliability. Since they generally have a lot of experience, are some older of age, and assume responsibility for work, they are considered to receive reliability from other organizational members. This study proved that it was possible to numerically express reliability of organizational members, which is an abstract concept, and analyze it. Therefore, it is expected that the analysis result will highly be likely to be used in the area of construction management.

Prediction of Prestressing Steel Stress at Ultimate State of Prestressed Concrete Members with External Unbonded Tendons (외부 프리스트레스트 콘크리트 부재의 극한상태에서의 강선응력예측식 제안)

  • 오병환;유성원
    • Journal of the Korea Concrete Institute
    • /
    • v.11 no.6
    • /
    • pp.13-24
    • /
    • 1999
  • The external, unbonded prestressed concrete(PSC) members exhibit very different structural behavior from that of internal bonded PSC members because of eccentricity change and slip occurrence during loading process. The purpose of the present study is to propose the ultimate failure stresses of prestressing (PS) steels for those external unbonded PSC members. To this end, a comprehensive analysis has been made using the nonlinear finite element analysis program developed recently for external unbonded PSC members by authors. A series of major influencing variables have been included in the analysis. It was found that the span-depth ratio, neutral axis depth-effective depth ratio, load geometry, amount of ordinary steel, and prestressing steel ration have great influence for the ultimate failue stress of PS steel is preposed and is compared with experimental dat as well as existing formulas for internal unbonded members. The Comparison indicates that the proposed equation agrees relatively well with experimental data and that existing formulas including ACI and AASHTO equations show some discrepancies from experimental ones. The present study allows more realistic analysis and design of prestressed concrete structures with external unbonded tendons.