• Journal of KIISE:Databases
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• v.32 no.3
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• pp.334-343
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• 2005

Complex queries such as path alld twig patterns have been the focus of much research on processing XML data. Structural join algorithms use a form of encoded structural information for elements in an XML document to facilitate join processing. Recently, structural join algorithms such as Twigstack and TSGeneric- have been developed to process such complex queries, and they have been shown that the processing costs of the algorithms are linearly proportional to the sum of input data. However, the algorithms have a shortcoming that their processing costs increase with the length of a queery. To overcome the shortcoming, we propose the segment join technique to augment the structural join with structural indexes such as the 1-Index. The SegmentTwig algorithm based on the segment join technique performs joins between a pair of segments, which is a series of query nodes, rather than joins between a pair of query nodes. Consequently, the query can be processed by reading only a query node per segment. Our experimental study shorts that segment join algorithms outperform the structural join methods consistently and considerably for various data sets.

• 한국IT서비스학회:학술대회논문집
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• 2008.11a
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• pp.326-329
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• 2008

본 논문에서는 정보체계 간 상호운용성 개선을 위해 공유 데이터 환경(SHADE) 기반의 DB 세그먼트 구현절차를 제안한다. 먼저 공유 데이터 서버의 개념과 특성을 제시하고 DB 세그먼트 네이밍 및 패키징에 대한 정의 및 형식 등을 분석한다. 그런 다음 SHADE 기반하에 DB 세그먼트 개발환경 및 개발자 역할을 제안하고 DB 세그먼트를 효율적으로 구축할 수 있도록 세그먼트 등록, 개발, 제출, 통합이라는 4단계 개발절차와 설치 및 사용절차 등이 포함된 구현절차를 제안한다. 향후 제안한 DB 세그먼트 구현절차를 소프트웨어 재사용과 연결성 향상을 통해 정보체계 간 상호운용성 개선에 도움을 줄 것으로 기대한다.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.121-129
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• 2008

study proposes a new key-segment closing method using thermal effect as a substitute to the process of set-back and reset-back for the FCM construction of a partially earth-anchored cable-stayed bridge. The proposed method is to artificially heat up the inside of girders located in the main span before closing the key-segment in a cantilever state. Then, the heat is removed after finishing the closure in a continuous bridge state. Using the changes in boundary conditions and structural systems, the proposed method can generate new member forces that reflect the advantage of the partially earth-anchored cable system. From the construction sequence analysis, it is found that the proposed method increases the efficiency of a partially earth-anchored cable-stayed bridge by reducing the compressive axial forces on the girders.

• Journal of Korean Society of Steel Construction
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• v.22 no.2
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• pp.161-171
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• 2010

Bridges have undergone distinctive development in accordance of the introduction of new materials and structural types. The importance on rapid construction technology is currently attracting more and more attention worldwidely as well as domestically because its effectiveness in reducing the overall construction cost. While a wide ranges of previous researches on rapid construction of super structures are available, the studies on substructures are quite limited. The development of the precast segmental internally confined hollow CFT piers are briefly introduced herein and design formulas are presented for pier segment joints, Also, a extensive parametric studies are carried out for the effect of the constitutive elements of the joints. Finally, the design formulas are verified throughout a series of extensive finite element analyses.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.113-120
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• 2010

Video proxy server which is located near clients can store the frequently requested video data in storage space in order to minimize initial latency and network traffic significantly. However, due to the limited storage space in video proxy server, an appropriate video selection method is needed to store the videos which are frequently requested by users. Thus, we present a time constraint multiple access technique to efficiently store the video in video proxy server. If the video is requested by user, it is temporarily stored during the predefined interval and then, delivered to the user. A video which is stored is deleted or moved into the storage space of video proxy server depending on the request condition. In addition, we propose a video deletion method in video proxy server for newly stored video data. The simulation results show that the proposed method performs better than other methods in terms of the block hit rate and the number of block deletion.

• The monthly packaging world
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• s.291
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• pp.88-91
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• 2017

최근 많은 제조사들이 선진국 등 고성장시장에서 수익 성장 기회를 찾는 데 어려움을 겪고 있다. 북미와 서유럽의 제조사들은 고객 분류 방식의 개선을 통해 새로운 돌파구를 찾고 있다. 그들은 세부적으로 구분된 고객 세그먼트의 요구사항을 정확히 충족하기 위해 새로운 맛, 크기, 포장 형태를 개발하고 있다. 소비자들은 쏟아져 나오는 신제품에 긍정적인 반응을 보일 뿐만 아니라 더 많은 제품을 요구하고 있어 SKU(Stock Keeping Unit)의 확산은 더욱 빨라지고 있다. 더욱이 온라인 판매가 확산됨에 따라 SKU 관리는 더욱 중요해지고 있다. SKU 관리에서 중요한 역할을 하는 대문자 마킹에 관해 Videojet Technologies의 글로벌 대문자 마킹 프린터(LPA) 비즈니스 책임자인 Bob Neagle과 이야기를 나눠봤다.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.383-391
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• 1998

Launching truss used for constructing the precast segmental concrete bridge has upper chord, lower chord and diagonal members. And the pin is used for connecting these members. From the field loading test carried out for investigating the actual behavior of launching truss, the great difference is analyzed between measured stress and calculated stress. Based on measured value, the structural analysis are carried out about assumed abnormal behavior of connection part. From the results of analysis, it is analyzed that the abnormal behavior of connection part greatly affect the structural behavior of launching truss. In addition, from the investigation of safety of launching truss, it is evaluated that the launching truss has enough safety with normal behavior of connection part.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.755-768
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• 2002

We investigate the effect of the data skew of join attributes on the performance of a pipelined multi-way hash join method, and propose two new hash join methods with load balancing capabilities. The first proposed method allocates buckets statically by round-robin fashion, and the second one allocates buckets adaptively via a frequency distribution. Using hash-based joins, multiple joins can be pipelined so that the early results from a join, before the whole join is completed, are sent to the next join processing without staying on disks. Unless the pipelining execution of multiple hash joins includes some load balancing mechanisms, the skew effect can severely deteriorate system performance. In this paper, we derive an execution model of the pipeline segment and a cost model, and develop a simulator for the study. As shown by our simulation with a wide range of parameters, join selectivities and sizes of relations deteriorate the system performance as the degree of data skew is larger. But the proposed method using a large number of buckets and a tuning technique can offer substantial robustness against a wide range of skew conditions.

• Journal of KIISE:Databases
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• v.29 no.3
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• pp.180-192
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• 2002

We investigate the effect of the data skew of join attributes on the performance of a pipelined multi-way hash join method, and propose two new harsh join methods in the shared-nothing multiprocessor environment. The first proposed method allocates buckets statically by round-robin fashion, and the second one allocates buckets dynamically via a frequency distribution. Using harsh-based joins, multiple joins can be pipelined to that the early results from a join, before the whole join is completed, are sent to the next join processing without staying in disks. Shared nothing multiprocessor architecture is known to be more scalable to support very large databases. However, this hardware structure is very sensitive to the data skew. Unless the pipelining execution of multiple hash joins includes some dynamic load balancing mechanism, the skew effect can severely deteriorate the system performance. In this parer, we derive an execution model of the pipeline segment and a cost model, and develop a simulator for the study. As shown by our simulation with a wide range of parameters, join selectivities and sizes of relations deteriorate the system performance as the degree of data skew is larger. But the proposed method using a large number of buckets and a tuning technique can offer substantial robustness against a wide range of skew conditions.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.571-578
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• 2002

In temporal database, extended time dimension for history management brings about complexity of join operation and increased cost. To solve this problem, a method that joins the divided segment time data after partition the time range into fixed time interval is introduced. But existing methods can't solve the ambiguity problem of time border that caused by temporal granularity in the partition point. In this paper, We suggested Fuzzy Minimum Interval Partition (FMIP) method that introduced the possibility distribution of fuzzy theory considered uncertainty time interval border in the partition line.