• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.135-137
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• 2005

A PC-based automatic system was developed for automatic titration in volatile basic nitrogen analysis by the microdiffusion method. The system used a CCD-type PC camera for the automatic detection of the titration end point. The camera checked whether the green value of a pixel on the red image of titrated solution became greater than the red value. The data from the automatic titration using the system were not significantly different (p>0.05) from those taken by manual titration. The agreement between means of data from manual titration and those from automatic titration was good.

• The KIPS Transactions:PartA
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• v.17A no.4
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• pp.167-172
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• 2010

This paper proposes a set of runtime test models for priority queues and shows the runtime test results based on the proposed test models for the representative priority queues: the traditional heap, post-order heap, and pairing heap. Among these heaps, the traditional heap is the worst in time complexity analyzed. But, according to our experimental results based on the test models proposed, it is shown that the slowest one is the pairing heap that utilizes pointers and the fastest one is the traditional heap. For the two implicit heaps, these results are in contrary to the fact that the post-order heap is better than the traditional heap in time complexity analyzed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.10
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• pp.2597-2604
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• 1996

본 논문에서는 주기억 데이터베이스 시스템에서의 효율적인 데이터 처리를 위하여 T*-트리라는 새로운 색인구조를 제시한다. T*-트리 색인구조는 기존의 디스크를 기반으로 하는 색인기법과 달리 모든 데이터가 주기억장치에 적재되어 있는 시스템에서 보다 빠른 데이터 접근과 메모리 공간의 효율적인 사용을 위해 주기억 데이터베이스 시스템에서 주로 사용되고 있는 T*-트리색인구조의 장점은 그대로 계승하면서 단점을 보완한 인덱스 구조이다. 본 논문에서 제시하는 T*-트리는 데이터 아이템에 대한 검색과 저장공간의 활용면에서는 T*-트리와 대동소이한 성능을 가지고 있으나, 범위 질의에서와 데이터 아이템에 대한 검색과 삭제시 중간노드에서의 노드간의 순회경로를 줄임으로써 보다 향상된 성능을 보여준다. 또한 T*-트리와 스레드 이진트리를 조합하는 경우에는 순회경로가 다소 단축되지만 중간노드에서 자신보다 높은 레벨의 후속 노드로의 순회는 기존의 인오더 트리 순회에 의존하지만, T*-트리에서는 후위포인터를 이용하므로 직접순회가 가능하게 된다. 본 논문에서는 제안된 T*-트리의 구조와 T*-트리의 검색, 삽입 및 삭제 연산을 위한 알고리즘을 설명한 후, 기존의 T*-트리와 성능분석을 실시하고 그 결과를 제시한다. 성능 분석결과 T*-트리는 데이터 검색의 경우 기존의 T*-트리와 거의 동일한 성능을 보였으며, 삽입과 식제등 색인구조의 변경시는 약간의 성능향상을 보였으나, 범위질의와 순차질의에서는 매우 향상된 성능을 나타냈다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.100-100
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• 2016

전자파표면유속계는 대표적인 비접촉식 계측기기로 최근 유량조사를 위해 활발하게 활용되고 있다. 국내에서 사용되고 있는 전자파표면유속계는 평수기 저유속에서도 측정이 가능하고 편각 측정이 가능하도록 개발되어 한 측정 지점에서 다 지점의 유속이 측정이 가능해 평수기 홍수기에 비교적 적은 인원으로 빠른 시간에 유량측정이 가능하다. 하지만 국내의 경우 전자파표면유속계가 과연 얼마만큼의 정확한 유속을 측정하는지에 대한 분석이 다소 부족한 실정으로 특히, 실제 하천에서 정확한 분석은 수행되지 않은 상태에서 유량 측정에 사용되고 있다. 전자파표면유속계를 실제 하천에서 사용할 경우 발생 할 수 있는 오차의 요인으로는 교량과 같이 높은 지점에서 측정을 수행할 경우 측정영역(Footprint or Illuminated area)에 따른 오차가 발생할 수 있는 가능성이 있고, 동일 측정 지점에 대해 수직각과 편각에 변화에 따른 유속 측정 오차가 발생할 수 있다. 이에 본 연구에서는 국내에서 개발된 Mutronics사의 전자파표면유속계(MWSCM; Microwave Water Surface Current Meter)에 레이저포인터를 부착하여 표면유속 약 0.5m/s ~ 1m/s의 자연 하천과 매우 유사한 실제 소하천 규모의 한국건설기술연구원 안동실험센터 직선하천에서 수직각(Tilt angle) 및 편각(Yaw angle)을 변화시켜가며 유속를 측정하였다. 그리고 측정된 결과를 활용하여 수직각과 편각의 변화에 따른 전자파표면유속계의 측정영역을 검토하였고, 동일한 측정 지점에 micro-ADV를 이용해 측정된 연직유속분포를 외삽하여 산정된 표면유속과 비교하여 전자파표면유속계의 측정 정확도를 분석하였다. 분석결과, 수직각(Tilt angle) 15도 이하에서는 유속 측정의 정확도가 떨어지는 것으로 나타났고, 편각(Yaw angle)이 커질수록 측정영역이 커지게 되어 변동 계수가 증가하는 것으로 나타났다. 그리고 전자파표면유속계의 측정 오차는 측정영역에 민감하게 반응하는 것으로 나타나 실제 전자파표면유속계를 이용한 유량측정 시 측정영역을 고려한 측정이 수행되어야 할 것으로 판단된다.

• The KIPS Transactions:PartB
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• v.15B no.5
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• pp.421-434
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• 2008

As computer graphics, virtual reality and augmented reality technologies have been developed, in many application areas based on those techniques, interaction for 3D space is required such as selection and manipulation of an 3D object. In this paper, we propose a framework for a vision-based 3D interaction which enables to simulate functions of an expensive 3D mouse for a desktop environment. The proposed framework includes a specially manufactured interaction device using three-color LEDs. By recognizing position and color of the LED from video sequences, various events of the mouse and 6 DOF interactions are supported. Since the proposed device is more intuitive and easier than an existing 3D mouse which is expensive and requires skilled manipulation, it can be used without additional learning or training. In this paper, we explain methods for making a pointing device using three-color LEDs which is one of the components of the proposed framework, calculating 3D position and orientation of the pointer and analyzing color of the LED from video sequences. We verify accuracy and usefulness of the proposed device by showing a measurement result of an error of the 3D position and orientation.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.5
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• pp.66-73
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• 2011

I try to solve the problem of the usage of the general software interrupt with the nested call of the software interrupt and the effective passing way of the parameters. The software interrupt should be protected against the indiscriminate access because it is used to call the system functions or to use the system resources by generating a software interrupt. But, it is difficult to effectively handle the SWI instruction because of its limited usage. I designed and implemented nested call of the software interrupt and the effective way that handle the parameters in the software interrupt service routine to solve this problem in this paper. In other words, from the single SWI call to the nested SWI call, I improved the software interrupt use all the more flexibly, and I compared and analyzed the strong and weak points of the two passing ways of the parameters. The main differences between these two ways are speed and readability. The stack pointer getting way incurred a lot of overhead although it has a very great readability. But, the stack pointer passing way producted 19% of the effectivity in speed by reduce overhead.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.207-215
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• 2012

This paper proposes a proxy-based caching optimization scheme for improving the streaming media services in wireless mobile ad hoc networks. The proposed scheme utilizes the proxy for data packet transmission between media server and nodes in WLANs, and the proxy locates near the wireless access pointer. For caching optimization, this paper proposes NFCO (non-full cache optimization) and CFO (cache full optimization) scheme. When performs the streaming in the proxy, the NFCO and CFO is to optimize the caching performance. This paper compared the performance for optimization between the proposed scheme and the server-based scheme and rate-distortion scheme. Simulation results show that the proposed scheme has better performance than the existing server-only scheme and rate distortion scheme.

• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.149-155
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• 2009

The frequency is widely used to measure the distance. In the warehouse, however, the frequency is apt to be interrupted by various unmade stuffs and cannot be easily applied to that kind of environment. This study will suggest the method to localize a worker in the warehouse exactly with calculating the time difference of arrival from the base position to a node or between each node and with 3-points pin pointer. This study will propose the localizing method using RFID tag and analyze the result using the suggested method. Also, the efficiency of suggested method will be increased with the simulation based on the information from the RFID tag.

• The KIPS Transactions:PartD
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• v.18D no.1
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• pp.35-44
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• 2011

Memory errors can cause not only program malfunctions but also even unexpected system halt. Though a programmer checks memory errors, some memory errors with low occurrence frequency are missed to detect. In this paper, we propose a method for effectively detecting such memory errors using instruction transition diagrams through analyzing assembly codes obtained by disassembling an executable file. Out of various memory errors, local memory return errors, null pointer access errors and uninitialized pointer access errors are targeted for detection. When applying the proposed method to various programs including well-known open source programs such as Apache web server and PHP script interpreter, some potential memory errors are detected.

• Journal of Korea Multimedia Society
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• v.9 no.9
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• pp.1118-1130
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• 2006

Existed pattern analysis algorithms in data streams environment have researched performance improvement and effective memory usage. But when new data streams come, existed pattern analysis algorithms have to analyze patterns again and have to generate pattern tree again. This approach needs many calculations in real situation that needs real time pattern analysis. This paper proposes a method that continuously analyzes patterns of incoming data streams in real time. This method analyzes patterns fast, and thereafter obtains real time patterns by updating previously analyzed patterns. The incoming data streams are divided into several sequences based on time based window. Informations of the sequences are inputted into a hash table. When the number of the sequences are over predefined bound, patterns are analyzed from the hash table. The patterns form a pattern tree, and later created new patterns update the pattern tree. In this way, real time patterns are always maintained in the pattern tree. During pattern analysis, suffixes of both new pattern and existed pattern in the tree can be same. Then a pointer is created from the new pattern to the existed pattern. This method reduce calculation time during duplicated pattern analysis. And old patterns in the tree are deleted easily by FIFO method. The advantage of our algorithm is proved by performance comparison with existed method, MILE, in a condition that pattern is changed continuously. And we look around performance variation by changing several variable in the algorithm.