Differential Specific Mechanical Energy as a Quality Parameter in Racing Alpine Skiing

2008 ◽  
Vol 24 (2) ◽  
pp. 121-129 ◽  
Author(s):  
Matej Supej

An important question in alpine skiing is how to determine characteristics of well-performed ski turns, an issue that has become more crucial with the arrival of new carving skis. This article introduces a new method for estimating the quality of skiing at each point of observation based on mechanical energy behavior that can be measured using established motion analysis techniques. It can be used for single-or multiple-skier analyses for evaluation of skiing technique as well as racing tactics. An illustration of its use is shown by analyzing 16 top-level racers using a 3-D kinematical system and video recorded during an alpine ski world cup race. Based on energy behavior of several racers, it is demonstrated that the most direct line with shortest radius of turn is not necessarily the most effective strategy in contrast to what some coaches believe.

2017 ◽  
Vol 2 (3) ◽  
pp. 24
Author(s):  
Nazeer El-Bialee ◽  
AbdelGawad Mohammed Saad ◽  
Mohamed Ibrahim El-Didamony ◽  
Gamal Zahran

Gluten free products remain the cornerstone for celiac patients. Insufficiency, poverty and little offered about gluten free products (quality and quantity) represented a high obstacle for Egyptian celiac patients. Therefore, the purpose of this research is to modify a single screw extruder to produce gluten–free pasta (GFP) (tagliatelle type). The GFP was made from corn flour under screw rotation speed (N) of 10, 25 and 50 rpm at 40, 65, 90 and 115 ºC of barrel temperature (BT). Extruder performance was evaluated as specific mechanical energy (SME) and expansion ratio (Er). The cooking quality of GFP as optimum cooking time (OCT), cooked yield (CY), swelling (Sw), cooking losses (CL) and sensory characteristics (appearance, colour, taste, mouth feel and overall acceptability) were evaluated. The better results of the GFP sensory evaluation were obtained at BT= 80 ºC, N =25 rpm and Er ≈ 1.38 with OCT ≈ 3.3 min, CY= 196%, Sw = 210% and CL= 16.3%. All parameters were given a direct proportion with processing variables N and BT, except CL. Furthermore, it can be predicted cooking properties values for GFP by SME value using the following equation; SME » 1.8675 (Er) + 0.8037 » 0.0608 (OCT)1.5984  » 8×10-17 (CY)6.7878 » 2×10-9 (Sw)3.494  » -0.0306 (CL) + 0.7877.


Author(s):  
Dennis Forte ◽  

The objective of this chapter is to demonstrate how the manipulation of extrusion processing parameters such as specific mechanical energy (SME) can directly influence the nutritional value of a given formulation component such as starch in a dry animal feed formulation.


2015 ◽  
Vol 10 (3) ◽  
pp. 361-368 ◽  
Author(s):  
Matej Supej ◽  
Kim Hébert-Losier ◽  
Hans-Christer Holmberg

Purpose:Numerous environmental factors can affect alpine-ski-racing performance, including the steepness of the slope. However, little research has focused on this factor. Accordingly, the authors’ aim was to determine the impact of the steepness of the slope on the biomechanics of World Cup slalom ski racers.Methods:The authors collected 3-dimensional kinematic data during a World Cup race from 10 male slalom skiers throughout turns performed on a relatively flat (19.8°) and steep (25.2°) slope under otherwise similar course conditions.Results:Kinematic data revealed differences between the 2 slopes regarding the turn radii of the skis and center of gravity, velocity, acceleration, and differential specific mechanical energy (all P < .001). Ground-reaction forces (GRFs) also tended toward differences (P = .06). Examining the time-course behaviors of variables during turn cycles indicated that steeper slopes were associated with slower velocities but greater accelerations during turn initiation, narrower turns with peak GRFs concentrated at the midpoint of steering, more pronounced lateral angulations of the knees and hips at the start of steering that later became less pronounced, and overall slower turns that involved deceleration at completion. Consequently, distinct energy-dissipation-patterns were apparent on the 2 slope inclines, with greater pregate and lesser postgate dissipation on the steeper slope. The steepness of the slope also affected the relationships between mechanical skiing variables.Conclusions:The findings suggest that specific considerations during training and preparation would benefit the race performance of slalom skiers on courses involving sections of varying steepness.


2020 ◽  
Vol 6 (2) ◽  
pp. 169
Author(s):  
Philip Nababan ◽  
Efendi Napitupulu ◽  
R Mursid

Abstrak: Penelitian ini bertujuan untuk: (1) Mengetahui tanggapan siswa terhadap kualitas media pembelajaran interaktif pada pembelajaran Teknik Pemesinan Bubut. (2) Mengetahui keefektifan media pembelajaran interaktif pada pembelajaran Teknik Pemesinan Bubut pada siswa program keahlian Teknik Pemesinan. Jenis penelitian ini adalah penelitian pengembangan. Data tentang kualitas produk pengembangan ini dikumpulkan dengan angket dan dianalisis dengan teknik analisis deskriptif kualiatatif. Hasil penelitian menunjukkan bahwa; (1) uji ahli materi pelajaran Teknik Pemesinan Bubut berada pada kualifikasi sangat baik (88,92%), (2) uji ahli desain pembelajaran berada pada kualifikasi sangat baik (85,21%), (3) uji ahli rekayasa perangkat lunak berada pada kualifikasi sangat baik (84,03%), (4) uji coba perorangan berada pada kualifikasi sangat baik (88,75%), (5) uji coba kelompok kecil berada pada kualifikasi sangat baik (91,35%) dan (5) uji coba lapangan berada pada kualifikasi sangat baik (88,31%). Hasil pengujian hipotesis membuktikan bahwa terdapat perbedaan antara hasil belajar siswa yang menggunakan media pembelajaran interaktif  dengan hasil belajar siswa yang menggunakan buku teks. Hal ini ditunjukkan dengan hasil pengolahan data diperoleh  thitung sebesar 4,68 dan ttabel sebesar 1,67 pada taraf kepercayaan 95 persen. Maka diperoleh bahwa thitung> ttabel. Disimpulkan bahwa  hasil belajar siswa yang menggunakan media pembelajaran interaktif dengan efektifitas sebesar 72,77 %. lebih tinggi dari hasil belajar siswa yang diajar dengan pembelajaran menggunakan buku teks dengan efektifitas sebesar 62,13%. Kata Kunci: media pembelajaran interaktif, teknik pemesinan bubut Abstract: This study aims to: (1) Determine student responses to the quality of interactive learning media on learning Lathe Machining Techniques. (2) Knowing the effectiveness of interactive learning media on learning of Machining Lathe in students of Machining Engineering expertise program. This type of research is development research. Data about the quality of this development product was collected by a questionnaire and analyzed by qualitative descriptive analysis techniques. The results showed that; (1) Lathe machining engineering subject matter expert test is in very good qualification (88.92%), (2) learning design expert test is in very good qualification (85.21%), (3) software engineering expert test is in in very good qualifications (84.03%), (4) individual trials were in very good qualifications (88.75%), (5) small group trials were in very good qualifications (91.35%) and (5 ) field trials are in very good qualifications (88.31%). Hypothesis testing results prove that there are differences between student learning outcomes using interactive learning media with student learning outcomes using textbooks. This is indicated by the results of data processing obtained by tcount of 4.68 and ttable of 1.67 at a confidence level of 95 percent. Then it is obtained that tcount> ttable. It was concluded that student learning outcomes using interactive learning media with an effectiveness of 72.77%. higher than student learning outcomes taught by learning to use textbooks with an effectiveness of 62.13%. Keywords: interactive learning media, lathe machining techniques


Author(s):  
Viktor Danilin ◽  
Yuri Baykovsky

Currently, there are about 200 ski resorts in Russia from Smolensk to Chukotka, which are located both in the low mountains (GC "Tyagacheva", "Sarochany", etc.), and in the middle mountains ("Abzakovo", "Bannoe Lake", etc. ) and highlands (regions of the Elbrus region, Dombay, Krasnaya Polyana, etc.). More than six million Russians go downhill skiing and snowboarding every year. Over the years, the quality of sports equipment and track equipment has changed significantly, which has led to an increase in speeds, an increase in injuries and a change in teaching methods. Currently, a large number of people die and are seriously injured at ski resorts every year due to the low quality of training in safe skiing, lack of control over the work of instructors, and the irresponsible attitude of the holders of ski resorts to the safety of providing services on the ski slopes.


Author(s):  
Sri Winarsih

This study aims to determine the appropriate steps in carrying out academic supervision so as to be able to improve the pedagogical competence of teachers, especially in the learning process which in turn will affect the improvement of the quality of education.The study was conducted in two cycles. Each cycle has different planning, implementation, observation and reflection. Research subjects of the principal and teacher. The school principal with his academic supervision measures, while the Kunto Darussalam Elementary School 017 teacher as an object as well as the subject in providing academic supervision treatment. Data collection techniques through class supervision with stages of supervising teachers in the learning process and observation of classroom learning, to record important events related to research, especially at the time of the processlearning takes place.Data analysis techniques that guide data processing using a percentage (%) of achievement with 100 constants. And to see the interpertation using score interpertation criteria to strengthen the interpretation in conclusions as follows: 80% - 100% (Very Good), 66% - 79 % (Good), 56% - 65% (Enough), and 40% - 55% (Less).The results showed that the ability of teachers in the implementation of the learning process experienced an increase in the percentage at each stage, from the first cycle reached an average of 63% (sufficient) and in the second cycle reached an average of 68% (good). There is an increase in teacher's ability by 5% from cycle I. In detail there is a significant increase in the initial condition of the school when compared to the final condition in the second cycle. The accuracy of teachers entering the class increased by 48%, the use of learning media increased by 32%, varied methods increased by 31%, and learning strategies increased by 36%.


2021 ◽  
Vol 54 (7) ◽  
pp. 1-37
Author(s):  
Jihyeok Park ◽  
Hongki Lee ◽  
Sukyoung Ryu

Understanding program behaviors is important to verify program properties or to optimize programs. Static analysis is a widely used technique to approximate program behaviors via abstract interpretation. To evaluate the quality of static analysis, researchers have used three metrics: performance, precision, and soundness. The static analysis quality depends on the analysis techniques used, but the best combination of such techniques may be different for different programs. To find the best combination of analysis techniques for specific programs, recent work has proposed parametric static analysis . It considers static analysis as black-box parameterized by analysis parameters , which are techniques that may be configured without analysis details. We formally define the parametric static analysis, and we survey analysis parameters and their parameter selection in the literature. We also discuss open challenges and future directions of the parametric static analysis.


2015 ◽  
Vol 60 (8) ◽  
pp. 66-80
Author(s):  
Anna Wierzbicka ◽  
Agata Żółtaszek

Maintaining security is one of public tasks that determine the quality of life of the population. This issue is the subject of much debate both social and political. An in-depth assessment of the situation requires a variety of analyzes, significant from the point of view of the implementation of appropriate, effective strategy to increase the sense of security among citizens. The aim of the paper is to compare the state of public safety in selected European countries. The study was conducted based on Eurostat data from the years 2005–2011.


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