• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1481-1500
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• 2016

Device-to-Device (D2D) communication underlaying macro-small cell networks, as one of the promising technologies in the era of 5G, is able to improve spectral efficiency and increase system capacity. In this paper, we model the cross- and co-tier D2D communications in two-tier macro-small cell networks. To avoid the complicated interference for cross-tier D2D, we propose a mode selection scheme with a dedicated resource sharing strategy. For co-tier D2D, we formulate a joint optimization problem of power control and resource reuse with the aim of maximizing the overall outage capacity. To solve this non-convex optimization problem, we devise a heuristic algorithm to obtain a suboptimal solution and reduce the computational complexity. System-level simulations demonstrate the effectiveness of the proposed method, which can provide enhanced system performance and guarantee the quality-of-service (QoS) of all devices in two-tier macro-small cell networks. In addition, our study reveals the high potential of introducing cross- and co-tier D2D in small cell networks: i) cross-tier D2D obtains better performance at low and medium small cell densities than co-tier D2D, and ii) co-tier D2D achieves a steady performance improvement with the increase of small cell density.

• Journal of Animal Science and Technology
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• v.62 no.2
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• pp.276-291
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• 2020

This study was conducted to investigate behavioral changes in laying hens (Hy-Line Brown) after transfer to a multi-tier system from the floor system and to examine their production performance. The hens were randomly divided into two groups and were allocated to the multi-tier system and the floor system at a commercial farm. Behavior of the laying hens was recorded by CCD (charge-coupled device) cameras and a digital video recorder. The data were scanned every 2 min to obtain an instantaneous behavioral sample or were immediately counted whenever the hens exhibited a designated behavior. Behavior changed dramatically during the first seven days. Egg production was higher in the multi-tier system, while cracked and dirty eggs were more frequent in the floor system (p < 0.05). No differences in mortality rate or egg quality were observed between the groups. In conclusion, the hens needed at least seven days to adapt to the multi-tier system. The multi-tier system was more efficient than the floor system in terms of production performance.

• Speech Sciences
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• v.4 no.1
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• pp.113-133
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• 1998

The system proposed in this paper prosodically transcribes the intonation patterns, prosodic structures, phrasings, and other prosodic aspects of Korean utterances, on four parallel tiers: a tone tier, an orthographic tier, a break index tier, and a miscellaneous tier. The tone tier employs two phrase accents (L* and H *), three accentual phrase boundary tones (L-, H-, LH-), and four intonational phrase boundary tones (L%,H%,LH%,LHL%) in order to provide a phonological transcription of pitch events associated with accented syllables and phrase boundaries. The break index tier uses five break indices, numbered from 0 to 4, which mark a prosodic grouping of words and its prosodic structure in an utterance. Among the five indices, the break index 3 and the break index 4 align with an accentual phrase boundary tone and an intonational phrase boundary tone, respectively, in the tone tier.

• 연구논문집
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• s.28
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• pp.239-246
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• 1998

Today’s information technology departments face a dilemma to create a competitive advantage for the organization by developing. deploying, and managing distributed applications that scale across the LAN, WAN, and Internet, while preserving investments in systems. Applications, information. IT organizations are today being asked to build the future, without breaking systems that maintain the current business. A possible answer to this dilemma is the implementation of a multi-tier distributed computing architecture. Multi-tier architecture has the potential to provide better, more timely information across the enterprise at a lower cost than the current combination of PC LAN, two-tier client/server, or mainframe applications that have been developed in most organizations. In this paper, we implement management information system based on distributed object middleware using multi-tier distributed computing architecture. This system uses Microsoft's implementation of DCOM/ActiveX and provides easily accessible web interface to the system users.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.171-174
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• 2003

다자간 채팅은 인터넷 기반에서 진보적인 발전을 한 분야이고, 네트워크 게임과 같은 어플리케이션 제작에 있어 필수적인 기술이다. 본 논문에서는 자바 기술을 이용하여 one-tier, two-tier 구조가 가진 불편한 유지보수, 데이터 은닉의 문제점을 해결하기 위하여 multi-tier architecture로 아바타를 사용하여 다자간 채팅시스템을 구현하였다. 또한 채팅에서 흥미를 유발하기 위한 캐릭터 전송기술, 다양한 문자를 보내기 위한 문자 포맷 기술을 구현하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.970-973
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• 2003

Recently, the development paradigm of enterprise information system has been moved from 2-tier environment to 3-tier environment. 3-tier environment makes possible to develop more efficient system in terms of the performance, extension, deployment and maintenance. The ship drawing process management system which manages a long-term drawing process and a great number of designers has to support an accuracy and a real-time of information but it is impossible because it is still served in 2-tier environment and some process of them is not developed yet. In this paper, we implemented the analysis and design of system based on CBD(Component Based Development) for the purpose of hanging the environment from two-dimensional Client/server architecture environment to COM＋ based 3-tier architecture environment. And by completing a development of total system, the productivity and the efficiency of the ship drawing process management system will be improved. And a wide reuse of components makes possible to improve the productivity and efficiency of system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.915-922
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• 2002

This paper presents an implementation of an Remote Examination System on Internet using Java and SWING GUI API. The system is consisted of three parts: generating examination part that is Java application, answering questions part that is Java Applet, reviewing results part that is Java Applet. The first part is implemented with the 2-tier client/server architecture and the last two parts is implemented the 3-tier client/server architecture. Database programming is done using Java JDBC API for database independence and portability. This system can be used the evaluation of lectures, and substituted for pen-and-pencil examinations or adopted to survey applications based on Internet.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1725-1733
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• 2012

This paper describes the design and implementation of a 3-tiered proxy driving system utilizing smartphones. This system provides customers with a convenient request facility, and enables proxy drivers to provide a prompt service based on customer's location information. Implemented system supports two methods such as the existing phone-call and the online requesting method using smartphones. Performance analysis shows that the higher the ratio of online requests, the greater the effect of decreasing of phone jockey's workloads and the reduction of request processing time through the automation of receipt and processing. From a proxy driver company's standpoint, this system minimizes the increase of phone jockeys, and improves customer satisfaction through good service quality. This system also helps the company reduce the cost and increase the market share.

• Journal of Information Processing Systems
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• v.4 no.1
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• pp.9-16
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• 2008

This paper describes the design and implementation of a two-tier DBMS for handling massive data and providing faster response time. In the present day, the main requirements of DBMS are figured out using two aspects. The first is handling large amounts of data. And the second is providing fast response time. But in fact, Traditional DBMS cannot fulfill both the requirements. The disk-oriented DBMS can handle massive data but the response time is relatively slower than the memory-resident DBMS. On the other hand, the memory-resident DBMS can provide fast response time but they have original restrictions of database size. In this paper, to meet the requirements of handling large volumes of data and providing fast response time, a two-tier DBMS is proposed. The cold-data which does not require fast response times are managed by disk storage manager, and the hot-data which require fast response time among the large volumes of data are handled by memory storage manager as snapshots. As a result, the proposed system performs significantly better than disk-oriented DBMS with an added advantage to manage massive data at the same time.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.2
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• pp.1-9
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• 2012

In this paper, we design and implement a DCS (Distributed Control System) based on dual field-bus for ship engine. For monitoring and controlling the condition of the ship engine, an implemented DCS is consisted of two-tier communication structure by using CAN (Controller Area Network) and MODBUS protocols. The first-tier is consisted of CAN protocol for sharing the condition of the ship engine by each implemented monitoring system. By using MODBUS protocol, the second-tier is used for communicating the monitoring data from an implemented DCS to AMS(Alarm Monitoring System). We verified and tested our scheme and implemented DCS by KR (Korea Register) technical rules through experimental tests.