• Journal of KIISE:Computing Practices and Letters
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• v.15 no.4
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• pp.231-243
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• 2009

Many DSP systems are streaming applications in which streams of data constantly flow through a set of filters. Dataflow programming paradigm is one of effective methods for representing these streaming applications. Dataflow programming model explicitly exposes parallelisms within an application, which helps compiling of the application onto a multicore platform. We propose SPEX(Signal Processing Extension), a language extension to a standard imperative language based on the parameterized dataflow model. Parameterized dataflow model is a kind of dataflow model that can express a modest fashion of dynamism contrary to the synchronous dataflow that can represent only static dataflow. SPEX facilitates characterizing an application written in conventional imperative languages such C/C++ as a streaming application. SPEX is comprised of a few keywords augmented to the conventional C++ syntax for representing dataflow paradigm. SPEX also restricts the syntax and semantics of C++ in order to fit the program within a certain streaming programming category. In this paper, we focus on the capability of SPEX in representing streaming computations within filters and streaming communications among filters.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2349-2360
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• 2000

In medical image processing, if new technologies arc developed, they arc applied to real clinical cases. The results are to be analyzed by doctors to improve the new technologies. So, it is important for doctors to have a tool that helps the doctors in applying the new technologies to clinical cases and analyzing the clinical results. In this paper, we design and implement a visual programming environment where non-programming experts, such as medical doctors, can easily compose a medical image processing application program. A set of image processing functions are implemented and represented as icons. Thc user selects functions by clicking correslxmding icons. The users can easily find necessary' functions from the visualized library. A user selects a function from the visualized library and [Jut the function node into a canvas of Visual Programming Interface. The user connects nodes to compose a dataflow diagram. The connected dataflow diagram shows the now of the program. Hyperbolic Tree is helpful in visualizing a set of function icons in a single screen because it provides both the whole stmcture of the function Iihrary and the details of the focused functions at the same time. We also developed a CUI builder where the user interfaces of the medical image processing applications are composed. Therefore. non'programming experts such as physicians can apply new medical image processing algorithms to clinical cases without performing complex computer programming procedures.

• Korean Journal of Computational Design and Engineering
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• v.21 no.4
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• pp.453-461
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• 2016

The trend of using Grasshopper with Rhino3D actively in architectural design process is recently spreading around the world. Well-known architects and designers such as Zaha Hadid, Patrik Schmacher is famous for using Grasshopper as their main design tool. As a tool for so-called 'Parametric Design', Grasshopper is receiving much attention all over the world. Grasshopper as a visual programming language has an advantage that designers and non-professionals of computer can easily learn it and use it to their works. However, those designers tend to make inefficient approaches with Grasshopper compared to computer programming professionals. Meanwhile, the difference between other programming languages and Grasshopper leads to the need of different approaches from other programming languages. This study aims to propose desired approaches of Grasshopper programming or scripting to be able to break through the inefficient approaches that designer is likely to make, by examining the characteristics of Grasshopper and exploring the appropriate programming approaches for Grasshopper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2313-2324
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• 1998

Although visual programming is used in many fields of computer science and engineering, some dis-advantages can be found when they work together in an integrated programming environment. To overcome these shortcomings, there have been researches in combining multiparadigm with visual programming. However they have failed because they tried to combine the paramdigms without any coceptural model and structured method. In this paper, we investigate a new multiparadigm visual programming environment (MVPE), in which dataflow paradigm, form-based paradign, direct manipulation paradigm, and object-oriented paradigm are integrated together in an object-oriented way, based on the conceptual model of "method = paradigm, " This MVPE would overcome the limits of visual programming, and may also lead to the new discipline of visual programming environment.vironment.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.4
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• pp.209-218
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• 2016

This paper proposes a new lifetime aware buffer mapping method of a synchronous dataflow (SDF) graph on a hybrid memory system with DRAM and PRAM. Since the number of write operations on PRAM is limited, the number of written samples on PRAM is minimized to maximize the lifetime of PRAM. We improve the utilization of DRAM by mapping more buffers on DRAM through buffer sharing. The problem is formulated formally and solved by an optimal approach of an answer set programming. In experiment, the buffer mapping method with buffer sharing improves the PRAM lifetime by 63%.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.9_10
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• pp.429-440
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• 2008

As embedded system becomes more complex, software development becomes more important in the entire design process. Most embedded applications consist of multi -tasks, that are executed in parallel. So, dataflow model that expresses concurrency naturally is preferred than sequential programming language to develop multitask software. For the execution of multitasking codes, operating system is essential to schedule multi-tasks and to deal with the communication between tasks. But, it is needed to execute multitasking code without as when the target hardware platform cannot execute as or target platforms are candidates of design space exploration, because it is very costly to port as for all candidate platforms of DSE. For this reason, we propose the serialized multitasking code generation technique from dataflow specification. In the proposed technique, a task is specified with dataflow model, and generated as a C code. Code generation consists of two steps: First, a block in a task is generated as a separate function. Second, generated functions are scheduled by a multitasking scheduler that is also generated automatically. To make it easy to write customized scheduler manually, the data structure and information of each task are defined. With the preliminary experiment of DivX player, it is confirmed that the generated code from the proposed framework is efficiently and correctly executed on the target system.