• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.2
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• pp.241-249
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• 1997

In this paper, a new technique is proposed for generating a minimum-length synchronizable test sequence that can be applied in the distributed test architecture where both external synchtonization and input/output operation costs are taken into consideration. the method defines a set of transformation rules that constructs a duplex digraph from a given finite state machine representation of a protocol specification rules that constructs a duplex digraph from a given finite state machine representation of a protocol specificatio such that a rural chinese postman tour of the duplex digraph can be used to generate a minimum-length synchronizable test sequence using synchronizable distinguishing sequences as the state identification sequence for each state of the given finite state machine. The method provides an elegant solution to the synchronization problem that arises during the application of a predetermined test sequence in some protocol test architectures that utilize remote testers.

• The Journal of Korean Association of Computer Education
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• v.6 no.1
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• pp.29-39
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• 2003

In this paper we proposed dynamic adaptive model based on discrete probabilistic distribution functions and user's profile for web media systems(web based hypermedia systems). The model represented that the application domain is modelled using a weighted direct graph and the user's behaviour is modelled using a probabilistic approach that dynamically constructs a discrete probability distribution functions. The proposed probabilistic interpretation of the web media structure is used to characterize latent properties of the user's behaviour, which can be captured by tracking user's browsing activity. Using that distribution the system attempts to assign the user to the best profile that fits user's expectations.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.17-24
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• 2007

Critical practicality problems are cause to search the presentation and contents according to user request and purpose in previous internet system. Recently, there are a lot of researches about dynamic adaptable ontology based system. We designed ontology based educational system which uses discrete probability and user profile. This system provided advanced usability of contents by ontology and dynamic adaptive model based on discrete probability distribution function and user profile in ontology educational systems. This models represents application domain to weighted direction graph of dynamic adaptive objects and modeling user actions using dynamically approach method structured on discrete probability function. Proposed probability analysis can use that presenting potential attribute to user actions that are tracing search actions of user in ontology structure. This approach methods can allocate dynamically appropriate profiles to user.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.1
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• pp.27-32
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• 2007

this paper the acoustic signature from a supersonic nozzle is measured and compared to the result of a program developed for a gas turbine noise prediction. In order to measure the jet Mach Number, the pressure and temperature at the settling chamber was measured along with pressures from a pitot-tube placed near the exit. The results are also compared to the ones obtained with a shadow graph technique. Jet noise produced by an imperfectly expanded jet contains shock associated noise, which consist of broadband noise and screech tone noise. For subsonic condition, the directivity is dominant to the downstream direction due to turbulence mixing noise. For supersonic conditions, however, the directivity is dominant toward upstream direction due to shock associated noise. The comparison with a jet exhaust noise prediction code shows good agreement at supersonic conditions but needs to be improved at subsonic speeds.

• The Journal of Natural Sciences
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• v.8 no.1
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• pp.115-121
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• 1995

The Conventional database management system is not applicable because of their inadequate performance and difficulty of CAD database that is dependant to hierarchical structure and to repeat accesses of large data. For effective management and easy tool integration of CAD database, hierarchy Interface System(HIS) is designed and GROCO(Graph Representation fOr Complex Objects) Model is presented. Hierarchy Interface System which is composed of two subsystems of a configurator and a converter is designed for the interface between a conventional database management system and CAD tools. GROCO Model is a directed cyclic graph having five node-types for representing semantics and supports efficiently CAD database characters having a hierarchical structure of complex objects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6C
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• pp.625-631
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• 2002

This paper presents a MSB-first digit-serial systolic array for computing modular multiplication of A(x)B(x) mod G(x) in finite fields $GF(2^m)$. From the MSB-first multiplication algorithm in $GF(2^m)$, we obtain a new data dependence graph and design an efficient digit-serial systolic multiplier. For circuit synthesis, we obtain VHDL code for multiplier, If input data come in continuously, the implemented multiplier can produce multiplication results at a rate of one every [m/L] clock cycles, where L is the selected digit size. The analysis results show that the proposed architecture leads to a reduction of computational delay time and it has much more simple structure than existing digit-serial systolic multiplier. Furthermore, since the propose architecture has the features of unidirectional data flow and regularity, it shows good extension characteristics with respect to m and L.

• Journal of KIISE:Software and Applications
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• v.33 no.12
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• pp.1022-1030
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• 2006

The location awareness is an important part of many ubiquitous computing systems, but a perfect location system does not exist yet in spite of many researches. Among various location tracking systems, we choose the RFID system due to its wide applications. However, the sensed RSSI signal is too sensitive to the direction of a RFID reader antenna, the orientation of a RFID tag, the human interference, and the propagation media situation. So, the existing location tracking method in spite of using the particle filter is not working well. To overcome this shortcoming, we suggest a robust location tracking method with a double layered structure, where the first layer coarsely estimates a tag's location in the block level using a regression technique or the SVM classifier and the second layer precisely computes the tag's location, velocity and direction using the particle filter technique. Its layered structure improves the location tracking performance by restricting the moving degree of hidden variables. Many extensive experiments show that the proposed location tracking method is so precise and robust to be a good choice for implementing the location estimation of a person or an object in the ubiquitous computing. We also validate the usefulness of the proposed location tracking method by implementing it for a real-time people monitoring system in a noisy and complicate workplace.

• Journal of the Korean association of regional geographers
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• v.16 no.4
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• pp.369-386
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• 2010

Migration usually derived from the gap of spatial efficiency and the attractiveness difference between the origin and the destination puts forth significant impact on the regional dynamics of population. Both migration and regional planning or policy are structurally interconnected, exerting impact each other within the circular loops. In order to observe migration characters in the regional dimension, this research depends on social network analysis(SNA) methods which easily portray interrelationship and its weight between the origin and the destination. In specific, it focuses on the application of centrality indicators in order to understand the in- and out-migration patterns and visualize them with spring graphs, pinpointing the in- and out-migration administrative units. This research deals with three migration patterns in 2001 and 2008, respectively: i) in- and out-migration between the nation and Chungbuk Province; ii) in- and out-migration within Chungcheong Areas; and iii) in- and out-migration within Chungbuk Province. Judging from Chungbuk examples, the highest in-migration was recorded at Heungduck District in terms of in- and out-migration between the nation and Chungbuk Province. Seoul and Gyeonggi were two major origins towards Chungbuk Province. Within Chungcheong Areas, Daejeon produced the highest in-migration in 2001. However, Chungnam took that position in 2008.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.253-253
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• 2019

유사의 이동은 하천, 해안 지역과 같은 수계에서 하상의 변동, 침식과 퇴적을 일으켜 지형적인 변화를 초래한다. 유사의 이동은 유사의 특성과 유체의 유수동역학적 특성에 의해 결정되며 유체특성 간의 복잡한 상호 작용에 의해 변화한다. 유사가 가지는 점착성은 유사의 특성에 큰 영향을 끼친다. 입자의 크기가 매우 작은 점착성 유사는 그 표면이 가지는 전자기적 점착력에 의해 주위의 1차 입자나 다른 작은 알갱이들이 서로 뭉치는 응집과 충돌에 의해 크기가 작아지는 파괴의 과정을 겪는다. 이 과정을 응집현상이라고 하며 응집현상을 통해 점착성 유사의 크기와 밀도, 침강속도는 계속해서 변화한다. 따라서 점착성 유사의 응집거동 고려한 유사 이동 연구는 필수적이다. 과거 연구의 많은 사례에서 유사의 크기와 농도는 비례 관계를 가지는 것이 일반적이라 알려져 있다. 그러나 실제 현장에서 측정한 결과 유사의 크기와 농도가 반비례 관계를 가지는 특이점이 발견되었다. 실측 연구에서 발견된 응집거동에 따른 유사의 특성의 특이한 변화를 설명하기 위해 1차원 연직 수치 모형(1DV)을 이용하여 수치 실험을 수행하였다. 모의 수행 시, 흐름 조건을 크기와 방향이 일정한 순방향흐름(Current)에 특정 주기와 진폭을 가지는 진동 흐름(Oscillatory Flow)을 추가하여 진행하였다. 플럭의 성장과 그에 따른 입자의 크기는 많은 현상에 영향을 받는다. 그 중 응집현상의 응집 과정과 파괴 과정 중 어떤 현상이 더 우세한지 그 경쟁관계를 파악하여 플럭의 크기의 증감을 예측할 수 있게 농도(?)와 난류소산매개변수(?)를 이용하여 $c/G^{0.5}$로 매개화하였다. 실험 결과, 순방향 흐름을 제외하고 스토크스파 흐름 조건을 이용하여 진행된 모의에서는 플럭의 크기와 농도가 반비례하는 현상을 관찰할 수 없었으며 $c/G^{0.5}$ 의 변화 역시 흐름의 속도와 농도가 더 큰 지점에서 큰 값을 가지는 일반적인 결과를 나타내었다. 그러나 같은 조건에서 순방향흐름을 추가하여 모의한 결과에서는 플럭의 크기와 농도가 반비례하는 현상을 나타냈다. 연직 방향 $c/G^{0.5}$의 변화를 나타낸 그래프에서 응집과 파괴의 우세에 따라 $c/G^{0.5}$ 가 역전되는 현상을 확인하였다. 즉, 플럭의 크기는 난류의 구조와 그 영향에 의해 농도와 비례관계를 갖지 않을 수도 있다고 판단된다. 또한 본 연구에서 정상류 흐름 조건의 유무에 따라 플럭의 크기와 농도가 비례하거나 반비례하는 상반된 결과를 보였다. 정상류 흐름 조건이 난류의 강도에 큰 역할을 하며 이에 따라 비선형 관계에 영향을 끼친다는 것을 발견하였다. 그러나 흐름의 영향에 대한 더 자세한 분석은 본 연구에서 진행되지 않았으며 향후 연구 시에 분명히 고려되어야 할 사항이다.

• The KIPS Transactions:PartA
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• v.18A no.6
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• pp.265-270
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• 2011

Even though 32-bit ISA based microprocessors are widely used more and more, 16-bit ISA based processors are still being frequently employed for embedded systems. Intel 8086, 80286, Motorola 68000, and ADChips AE32000 are the representatives of the 16-bit ISA based processors. However, due to less expressiveness of the 16-bit ISA from its narrow bit width, we need to execute more 16-bit instructions for the same implementation compared to 32-bit instructions. Because the number of executed instructions is a very important factor in performance, we have to resolve the problem by improving the expressiveness of the 16-bit ISA. In this paper, we propose a new pair register allocation algorithm to enhance an original graph-coloring based register allocation algorithm. Also, we explain about both the performance result and further research directions.