The fundamental period of a building plays a critical role in determining structural behavior during strong motions such as earthquakes and estimating building base shear in the new design of structures, as well as target displacement in seismic assessment of existing buildings. Thus, having an appropriate estimation of the fundamental period of buildings can considerably affect design and evaluation processes. In this research, to investigate the effects of damages on fundamental periods, ambient vibration tests were conducted on 22 seismically-damaged reinforced concrete (RC) buildings following the earthquake of Sarpol-e Zahab 2017. The obtained values for fundamental periods were compared with their counterparts calculated by empirical relations proposed in the first and fourth edition of the Iranian Code of Practice for Seismic Resistant Design of Buildings (Standard No. 2800) and the first revision of Instruction for Seismic Rehabilitation of Existing Buildings (No. 360). The obtained results for damaged RC buildings with moment resisting frame show a significant difference between fundamental periods of ambient vibration tests and empirical relations such that in a building with a damage state of 4, the obtained period from ambient vibration tests was 2.32 times greater than the calculated value using empirical relations. Furthermore, in retrofitted RC buildings, fundamental periods from empirical relations were up to 1.7 times greater than values determined using ambient vibrations. Therefore, two empirical relations for determining fundamental periods of damaged RC buildings with moment resisting frames and retrofitted RC buildings by adding shear walls are proposed by fitting curves on the obtained results of ambient vibration tests.

Natural period of vibration (or natural frequency) is one of the structural dynamic characteristics. It does not depend on seismic loading and depends only on buildings' specifications. There are some analytical and experimental methods for determination of natural periods. In this paper, the natural periods of a three-story building are studied using free vibration test. This building seismically induced by initial displacement in X and Y directions. The structural responses are measured by strong video camera and two-frequency GPS device mounted on the roof. Image processing was used for determination of natural periods (or natural frequencies). The tests were repeated for two directions. Analytical methods were done for controlling of the experimental results. For example, the natural frequencies in X direction were determined 1.07, 1.09 and 0.93 Hz using GPS, image processing and analytical methods respectively. The natural frequencies for Y direction were also obtained 1.13, 1.19 and 1.08 Hz respectively. Comparing the results of the image processing and GPS measurements indicate good convergence results of the two methods in determination of the dynamic characteristics of structures. The results from analytical method also are the same as the experimental results approximately. The small error is due to simulation of the model in analytical software.

Robust estimation of the fundamental elastic period of the buildings is essential for obtaining realistic seismic base shear. Seismic design codes provide a variety of equations to calculate the fundamental elastic period of vibration for steel moment frame buildings. The empirical equations are mainly based on the building height and do not take into account the effects of irregularity and soil-structure interaction. In this paper, an empirical predictive equation is developed to estimate the fundamental elastic period of steel moment frames. The predictive equation includes parameters that represent irregularity effects and soil-structure interaction. The database used in this study consists of architectural and geotechnical data for 45 building cases. The proposed predictive equation shows satisfactory accuracy. The predicted results are then compared to the values obtained from Iranian 2800 seismic design code, ASCE7-16 and UBC-97. The proposed predictive equation is also verified by 10 fundamental elastic periods obtained from analytical models. The fundamental elastic period was derived using the predictive equations that are specifically more accurate for mid- and high-rise buildings compared to seismic design codes. The values obtained from seismic codes are well below the realistic values for the buildings.

نگرش نیچه به مسئله انسان و حقیقت او، بر اساس اندیشه ها ی مادی گرایانه و تمایل به اصالت تجربه است که پیامدهای ویژه ای به همراه دارد. پژوهش حاضر با روش توصیفی و تحلیلی به منظور بررسی مختصات انسان شناختی از دیدگاه نیچه و ارزیابی پیامدهای آن در پرتو آرای علامه طباطبایی شکل گرفته است. بر اساس یافته‎های پژوهش، نیچه با نفی عقل گرایی و بی اعتبار نمودن ارزش ها ی اخلاقی و دینی مورد پذیرش زمان خویش، انسان را تا پرتگاه نیست گرایی می کشاند. لکن برای نجات وی از این وهله بحرانی، انسان را به باور توانمندی و اصالت قدرت خویش دعوت می نماید که ظهور تمام عیار آن در ابر انسان نمود یافته است. این در حالی است که علامه طباطبایی چنین تقلیل گرایی از شخصیت انسان و ترجیح  تن بر روان را برنمی تابد. زیرا نفی عقل گرایی و ستیز با ابعاد الهی متافیزیک نتیجه ای جز بی اعتبارشدن اوزان اندیشه ورزی و خردگرایی ندارد. وی همچنین منشأ اصلی پوچ انگاری در زندگی انسان را، حذف خدا و انگاره ها ی معنوی و ارزشی می داند و قرب الهی را به عنوان غایت اصلی زندگی مطرح می کند. غایتی که در سایه آن زندگی فردی و جمعی انسان بر اساس هدفمندی، معناداری و عدالت شکل می گیرد.

In this paper, firstly, existing methods for determining the behaviour factor of moment-resisting steel frames and their range of applicability for multi-degrees of freedom frames are reviewed. Modifications of this factor for multi-degree of freedom moment-resisting steel frames are then indicated. Necessary modifications in determining the behaviour factor of frames involve the period and the base shear distribution factor for a given earthquake loading code. The effect of storeys, spans and connections of frames on behaviour factor were considered over range of values for these factors for frames up to three spans and eight storeys. Based on the results, new relationships for the period and the behaviour factor of moment-resisting steel frames are presented.

تعریض هایدگر به تعریف ارسطویی «انسان حیوان ناطق است» (ζώον λόγον έχον/زُوون لِگون اِشون) فصلی مفصل و همواره گشوده در اندیشۀ اوست. به خصوص ترجمه، و به زعمِ او تفسیر لاتینی آن animal rationale (حیوان عاقل) بارها در آثار هایدگر پس از 1935 در خدمت نقادی های همه جانبه اش بر مابعدالطبیعۀ غربی مشاهده می شود. حیوان عاقلْ فهمی از انسان را بازمی گوید که در بُن مابعدالطبیعه و بر پی اش در بنیان تاریخ فکر و فرهنگ مغرب زمین هست. نوشتۀ حاضر بر آن است که موضوعیت و اهمیت این تعریف را در اندیشۀ هایدگر نشان بدهد. مباحث مربوط به تعریف ارسطویی به طورِ کلی در دو جهت اصلی بسط داده می شود: نخست، پرسش از انسان، ولی به اعتبارِ آنکه درحقیقت مضمون و محتوای پرسش از وجود است؛ دوم، مسئلۀ زبان؛ اما تأکید پژوهش حاضر بر مسائل مربوط به زبان است. نخست «مقدمه»، موضوعیت پرسش از انسان و نیز تعلقش به پرسش از وجود را نشان می دهد. پس از آن، بخش اول براساسِ درس گفتار مفاهیم اصلی مابعدالطبیعه حدود تقریبی نظام مسائل زبانی برآمده از این تعریف را معلوم می کند. هایدگر مبنایش را برای طرح آنها بر λόγος (لوگوس) به معنای نطق یا سخن می گذارد که آن را هم از همین تعریف ارسطو برگرفته است. سرانجام، بخش دوم همان مسائل را در وجود و زماننشان می دهد.

In this paper, the effects of connection stiffness on main period of vibration and behavior factor of moment resisting steel frames with semi-rigid connections are evaluated. For this purpose, behavior of different moment resisting steel frames with semi-rigid connections with 1,2, and 3 spans, and 1, 2, 4, 6 and 8 stories and with different connection stiff nesses are considered. Based on the results, new relationships for the main period and behavior factor of moment resisting still frames with semi rigid connections are purposed.