Near optimal time boundary controllability for a class of hyperbolic equations

2006 ◽  
pp. 307-312 ◽  
Author(s):  
Walter Littman
Keyword(s):  
Hyperbolic Equations ◽  
Optimal Time ◽  
Boundary Controllability ◽  
Time Boundary

scholarly journals Exact boundary controllability of coupled hyperbolic equations

2013 ◽  
Vol 23 (4) ◽  
pp. 701-709 ◽  
Author(s):  
Sergei Avdonin ◽  
Abdon Choque Rivero ◽  
Luz De Teresa
Keyword(s):  
Wave Equations ◽  
Hyperbolic Equations ◽  
Basis Property ◽  
Distributed Parameter ◽  
Exact Boundary Controllability ◽  
Boundary Controllability ◽  
One Dimensional ◽  
Riesz Basis Property ◽  
Exact Boundary ◽  
Dimensional Wave

Abstract We study the exact boundary controllability of two coupled one dimensional wave equations with a control acting only in one equation. The problem is transformed into a moment problem. This framework has been used in control theory of distributed parameter systems since the classical works of A.G. Butkovsky, H.O. Fattorini and D.L. Russell in the late 1960s to the early 1970s. We use recent results on the Riesz basis property of exponential divided differences.

Investigations on skeletal growth zones via bone scans as base of determination of optimal time for surgery in mandibular asymmetry

2000 ◽  
Vol 39 (05) ◽  
pp. 121-126 ◽  
Author(s):  
R. Werz ◽  
P. Reuland
Keyword(s):  
Bone Growth ◽  
Region Of Interest ◽  
Tracer Uptake ◽  
Optimal Time ◽  
Mandibular Bone ◽  
The Third ◽  
Mandibular Asymmetry ◽  
Bone Scans ◽  
Epiphyseal Plates

Summary Aim of the study was to find out wether there is a common stop of growth of mandibular bone, so that no individual determination of the optimal time for surgery in patients with asymmetric mandibular bone growth is needed. As there are no epiphyseal plates in the mandibular bone, stop of growth cannot be determined on X-ray films. Methods: Bone scans of 731 patients [687 patients (324 male, 363 female) under 39 y for exact determination of end of growth and 44 (21 male, 23 female) patients over 40 y for evaluation of nongrowth dependant differences in tracer uptake] were reviewed for the study. All the patients were examined 3 hours after injection of 99mTc-DPD. Tracer uptake was measured by region of interest technique in different points of the mandibular bone and in several epiphyseal plates of extremities. Results: Tracer uptake in different epiphyseal plates of the extremities shows strong variation with age and good correlation with reported data of bone growth and closure of the epiphyseal plates. The relative maximum of bone activity is smaller in mandibular bone than in epiphyseal plates, which show well defined peaks, ending at 15-18 years in females and at 18-21 years in males. In contrast, mandibular bone shows no well defined end of growing but a gradually reduction of bone activity which remains higher than bone activity in epiphyseal plates over several years. Conclusion: No well defined end of growth of mandibular bone exists. The optimal age for surgery of asymmetric mandibular bone growth is not before the middle of the third decade of life, bone scans performed earlier for determination of bone growth can be omitted. Bone scans performed at the middle of the third decade of life help to optimize the time of surgical intervention.

Elemen Merentasi Sempadan Masa Dalam “Ghiyath al-Umam” Karya Imam al-Haramayn al-Juwayniyy

Sains Insani ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 52-60
Author(s):  
Mohammad Zaini Yahaya ◽  
Muhammad Adib Samsudin ◽  
Mohd Izhar Ariff Mohd Kashim
Keyword(s):  
Qualitative Study ◽  
Document Analysis ◽  
The People ◽  
Time Boundary

In the study school of thought, an exposure to the context of across the time boundary known as "al-fiqh al-taqdiri" is a special feature in the formation of the Hanafi sect. It is also a feature shared by other sects including the Syafie sect. The authors chose the book of "Ghiyath al-Umam" by Imam al-Haramayn al-Juwayniyy (419H-478H) for this study as the book was loaded with elements across the time compared to his other books. This study is a qualitative study and the design is document analysis. The study of Ghiyath al-Umam's book shows how far Imam al-Haramayn's imagination that has not been reflected by most of the people at his time. But some have already happened now and some might happen in the future.Keywords: civilization, futuristics, Syafie sect ABSTRAK: pengajian sejarah mazhab kita biasa didedahkan bahawa fiqh merentasi sempadan masa yang dikenali sebagai “al-fiqh al-taqdiri” merupakan ciri istimewa dalam pembentukan mazhab Hanafi. Hakikatnya dengan berlalunya zaman ia turut menjadi ciri yang dikongsi bersama oleh mazhab-mazhab lain termasuk mazhab Syafie. Untuk melihat kebenaran teori ini penulis memilih kitab “Ghiyath al-Umam” karangan Imam al-Haramayn al-Juwayniyy (419H-478H). Imam al-Haramayn merupakan antara tokoh terawal yang tersohor dalam bidang fiqh syafie dan usul al-fiqh di samping bidang ilmu kalam. Karya-karya beliau dalam bidang fiqh mazhab Syafie dan usul al-fiqh aliran mutakallimin menjadi sumber utama dalam disiplin masing-masing. Pandangan-pandangan beliau sangat berautoriti dan dinukilkan oleh para ulama muhaqqiqun seperti Imam al-Nawawiyy dalam fiqh Syafie dan Fakhr al-Din al-Raziyy dalam bidang usul al-fiqh. Justeru beliau ialah tokoh yang sangat bersesuaian untuk tujuan kajian ini. Kitab Ghiyath al-Umam dijadikan fokus kajian memandangkan kitab ini sarat dengan elemen merentasi masa berbanding kitab-kitab beliau yang lain. Kajian ini merupakan kajian kualitatif dan reka bentuknya adalah analisis dokumen. Kajian terhadap kitab Ghiyath al-Umam dapat menunjukkan betapa jauhnya imiginasi Imam al-Haramayn yang tidak tergambar oleh sebahagian besar manusia ketika itu. Namun sebahagiannya sudah pun berlaku pada masa ini dan sebahagiannya mungkin akan berlaku pada masa akan datang.Kata Kunci: peradaban, futuristik, fiqh mazhab Syafie

Working up to the wire…

2019 ◽  
Vol 13 (2) ◽  
pp. 198-206
Author(s):  
Philippa Smethurst
Keyword(s):  
Psychotherapeutic Processes ◽  
Internal Structures ◽  
The Wire ◽  
Power And Energy ◽  
Time Boundary ◽  
The Way

This is a reflection on the power of endings and time boundaries, exploring the way that time can act as a catalyst in psychotherapeutic processes. The article describes the ending processes with five clients. These occurred simultaneously due to the author’s relocation. Some responses illuminate hitherto hidden and intractable internal structures, and in others the intensity of the limit acts an impetus for the client to grasp something new. Drawing on Power’s comprehensive book: Forced Endings in Psychotherapy and Psychoanalysis (2016), the author reflects on the power and energy springing from the setting of the time boundary and the different dynamics created in client and therapist. There is acknowledgement of the pressure that this can create in the therapist and also there are reflections about what ultimately may be achieved.

RESULTS OF TESTICULAR BIOPSIES IN CRYPTORCHIDISM, CONCERNING OPTIMAL TIME OF TREATMENT

1965 ◽  
Vol 49 (4_Suppl) ◽  
pp. S15 ◽  
Author(s):  
W. Ch. Hecker ◽  
R. Daum ◽  
H. Hienz ◽  
O. Heiderer
Keyword(s):  
Optimal Time
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