Young-Hwan Jang

Design of Effective Indexing Technique in Hadoop-Based Database

The recent rapid increase in the amount of data to be processed has led to the increased use of dispersed parallel processing of large-scale data analysis using open-source Hadoop’s MapReduce framework. The large-data processing method proposed by Google and Hadoop which implemented this are representative dispersed parallel processing methods, and the data are dispersedly saved on the HDFS(Hadoop Distributed File System). Such HDFS uses its own indexing technique when it comes to searching specific values from the saved files. Techniques that use conventional index, however, leads to problems like reduced search performance by not considering update and saving index in the disc. Therefore, the paper proposes effective DB indexing technique on Hadoop-based database.

Design of TDD-Based Automation System for Android Application Test Automation

The Android platform does not support interoperability among different platforms, and this causes difficulty for developers because they must test applications on different platforms and devices. To solve this problem, this study proposes a test automation system applying test driven development (TDD) that allows automatic performance of repetitive tests. To design the proposed system, test case generation was automated using Annotation.

Design of ECG Data Compression Algorithm for Efficient M2M-Based Mass Biometric Data Transmission

Thanks to the design of different portable subminiature sensors and wired and wireless communication technology, the U-Healthcare service is getting vitalized. A mass amount of raw data is processed in real time when this U-Healthcare service is provided, and efficient processing and storage technologies are required accordingly. Therefore, this paper proposed an ECG data compression algorithm that is improved to efficiently transmit M2M-based mass biometric data.

Design of Clustering Algorithm for Efficient Energy Management in Wireless Sensor Network Environments

Recently, there has been an active research effort on Wireless Sensor Network (WSN) where the sensor nodes consume energy efficiently by communicating between the nodes directly without a network infrastructure. However, previously proposed protocols require regular re-establishment of clusters, which leads to unnecessary energy consumption. Moreover, there is a large energy consumption because a cluster head that is placed far apart from a sink node directly transmits data to the sink nodes. Therefore, in this paper, we analysis the problems of the previous clustering techniques and protocols, and designed a clustering algorithm for efficient energy consumption through the use of an energy threshold during cluster re-establishment and data transmission route selection.

Design of TensorFlow-Based Proactive Smart Home Managers

In recent years, with IoT(Internet of Things) technology as the main focus, device operation and control technology in smart homes has been attracting considerable attention, and home IoT device management services are being provided by various companies, including communication companies. The smart home manager system manages smart devices used in homes, and it provides only the status value information and control function of the currently registered devices. Thus, unnecessary access procedures occur due to the characteristic of the smart home, which uses a smart device repeatedly for the same purpose. To resolve such shortcomings, in this paper, the Proactive Smart Home Manager has been designed, which can predict and suggest users the next steps to take by user usage pattern analysis and inference via machine learning.

Design of Smart Cattle Shed System Based on BLE Beacon to Improve Power Consumption

In recent years, a cattle shed management system using the IoT technology has been introduced to resolve the reduction in productivity due to aging society and lack of labor force in the livestock industry in Korea. However, existing cattle shed management systems have not been suitable for small and medium-sized cattle sheds due to a short communication range and excessive power consumption as a result of the use of ZigBee-based wireless communication. Thus, the present paper designed a smart cattle shed system based on BLE(Bluetooth Low Energy) Beacon to improve power consumption.

Design of Nonlinear Data-Based Wellness Content Recommendation Algorithm

As IT technology has advanced and people’s interest in wellness has increased, recommendation algorithms are being developed to allow people to use wellness content easily. However, existing recommendation algorithms use data entered by users and content-based filtering to recommend content, making it difficult to recommend areas of interest which change in real time. Therefore, in this paper we propose an algorithm which creates user information based on nonlinear social network data and makes recommendations in real time in order to reflect the user’s recent interests. The test result verified that the proposed algorithm improved accuracy by 31% compared to that of the existing content-based recommendation algorithm.

Design and Implementation of App Control System for Improving the Security of the Mobile Application

최근 모바일 기기를 소유한 사용자가 증가하면서 기업에서도 모바일 기기의 보안성이 보장된 관리 환경 구현이 가속화됨에 따라 기업은 개인의 기기를 통제하고 효율적 관리를 위해 MDM을 도입하였으나 기존 MDM의 App 관리 기능은 관리자가 해당 App을 등록하기 전까지 보안 위협을 막을 수 없다. 따라서 본 논문에서는 이러한 문제점을 해결하기 위해 보안성 향상을 위한 애플리케이션 제어 시스템을 제안한다. 제안 시스템을 설계하기 위해 MDM의 기능과 인증 기술을 분석하였고, 시스템 아키텍처를 정의 하여 사내의 정보 유출을 방지할 수 있는 모바일 기반 응용 제어 시스템을 설계 및 구현하였다. 구현한 제어 시스템의 보안성을 평가하기 위해 국제공통평가기준의 보안성 평가 항목을 기준으로 테스트 시나리 오를 작성해 테스트를 진행하였다. 테스트 결과 평균 40%의 보안성이 향상된 결과를 확인하였다.