Is There a Need for a Fundamentally New Classification of Musical Instruments?

В статье предлагается новый принцип классификации музыкальных инструментов, основанный не на первичности источника звука при неизменной вторичности способа извлечения, а на полном равноправии этих компонентов. Для композитора и исполнителя всегда важнее способ извлечения звука, поскольку его источник - не более чем предпосылка тонообразования. Нелогичность общепринятой классификации становится очевидной уже при обращении к ударным инструментам: например, удар по мембране малого барабана делает его мембранофоном, а по обручу - идиофоном. Однако для музыкальной практики в первую очередь имеет значение способ извлечения звука на малом барабане и его принадлежность к ударным инструментам. В качестве примера также доказывается, что большое семейство гармоник надо определять не как «идиофоны с дутьем» и не как аэрофоны, согласно систематике выдающихся классиков инструментоведения Э. Хорнбостеля и К. Закса, а как пневматико-клапанные ламеллафоны. Автор статьи приходит к выводу, что музыкальные инструменты целесообразно классифицировать так, как это принято в академическом инструментарии: не на идиофоны, мембранофоны, хордофоны и аэрофоны, а, к примеру, на струнные смычковые, духовые и ударные - в симфоническом оркестре; целесообразно изменить принципы классификации и в других инструментальных составах. The article proposes a new principle of classification of musical instruments, based not on the primacy of the sound source with the constant secondary of the extraction method, but on the full equality of these components. For the composer and performer, the method of sound extraction is always more important, since its source is no more than a prerequisite for tone formation. The illogic of the generally accepted classification becomes obvious when referring to percussion instruments: for example, a blow on the membrane of a snare drum makes it a membranophone, and on a hoop-an idiophone. However, for musical practice, the method of extracting sound on a snare drum and its belonging to percussion instruments is primarily important. As an example, it is also proved that a large family of harmonics should be defined not as “idiophones with blowing” and not as aerophones, according to the systematics of the outstanding classics of instrumentation E. Hornbostel and C. Sachs, but as pneumatic-valve lamellaphones. The author of the article comes to the conclusion that it is advisable to classify musical instruments as it is customary in academic instruments: not into idiophones, membrano-phones, chordophones and aerophones, but, for example, into strings, brass and percussion-in a symphony orchestra; it is advisable to change the principles of classification in other instrumental sets also.

A Prosthetic Socket with Active Volume Compensation for Amputated Lower Limb

Typically, the actual volume of the residual limb changes over time. This causes the prosthesis to not fit, and then pain and skin disease. In this study, a prosthetic socket was developed to compensate for the volume change of the residual limb. Using an inflatable air bladder, the proposed socket monitors the pressure in the socket and keeps the pressure distribution uniform and constant while walking. The socket has three air bladders on anterior and posterior tibia areas, a latching type 3-way pneumatic valve and a portable control device. In the paper, the mechanical properties of the air bladder were investigated, and the electromagnetic analysis was performed to design the pneumatic valve. The controller is based on a hysteresis control algorithm with a closed loop, which keeps the pressure in the socket close to the initial set point over a long period of time. In experiments, the proposed prosthesis was tested through the gait simulator that can imitate a human’s gait cycle. The active volume compensation of the socket was successfully verified during repetitive gait cycle using the weight loads of 50, 70, and 90 kg and the residual limb model with a variety of volumes. It was confirmed that the pressure of the residual limb recovered to the initial state through the active control. The pressure inside the socket had a steady state error of less than 0.75% even if the volume of the residual limb was changed from −7% to +7%.

Development of a data acquisition program to measure the exhaust time of a pneumatic valve

This paper deals with development of a data acquisition program to measure the exhaust time of a mechanical actuated pneumatic valve. The volume, which will be exhausted is determined by a so-called end of line testing procedure. The data acquisition unit is an Advantech ADAM 4117 8 channel analogue input module. The measuring and logging program is developed in LabVIEW software. The program provides the data in comma separated value file format for postprocessing opportunities.

A Novel Bio-Inspired Pneumatic Valve Adapter for Soft Robotic Vasculature

This paper proposes a novel pneumatic valve adapter that decreases the size and quantity of pneumatic tubes and valves necessary for soft robotics by mimicking cardiovascular systems. Some cardiovascular systems, evolved to be powered by a single reservoir, the heart, which in turn powers the rest of the body by systematically opening and closing valves as needed. The presented valve adapter consists of a set of concentric tube, where both tubes have strategically patterned holes. The inner tube can be moved translationally and rotationally to align with designated hole positions in the outer tube, thus opening and closing pathways to chambers for pressure flow. The two-tube system can be used to either pressurize a chamber or depressurize a chamber or multiple chambers simultaneously.