• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.04a
• /
• pp.661-664
• /
• 2012

스마트폰 사용이 급증하고 있는 현재, 안드로이드 OS 기반 스마트폰 점유율이 가장 큰 상승세를 보이고 있다. 하지만 안드로이드 OS는 자가-서명 인증서(self-signed certificate)로 애플리케이션을 검증하여, 많은 보안상의 취약점을 내재하고 있다. 자가-서명 인증서의 검증 취약점을 이용하여, 악의적인 공격자는 기존 정상 애플리케이션에 악성코드를 삽입, 리패키징(Repackaging) 하여 마켓에 유포할 수 있다. 이러한 문제를 해결하기 위해서, 본 논문에서는 안드로이드 애플리케이션의 서명 파일을 이용한 애플리케이션 리패키징 여부를 탐지하는 기술을 설계 및 구현한다.

• Asia pacific journal of information systems
• /
• v.31 no.4
• /
• pp.527-542
• /
• 2021

The government-driven open data policies are on the rise to protect consumers from misunderstandings and monitor the companies. However, in contract-based industries such as insurance, the contract-inherent characteristics make information asymmetry between consumers and companies. Our paper focuses on insurance contracts where the contingency has high uncertainty of occurrence, and the clauses may incur high costs of reading. Given those contracts, we hypothesized that the contract's clear statement decreases customer dissatisfaction and lowers the number of complaints. To empirically support the claim, we collected customers' complaint documents of insurance companies and insurance contracts from 2005 until 2017. Our econometric models showed that clearer statements and words significantly reduce the complaints after controlling for firm-specific heterogeneity and time-specific heterogeneity. We identify that insurance companies' complaint ratio significantly differ depending on the insurance contract, including specific clauses and words.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.2
• /
• pp.559-565
• /
• 2011

The following noble series of statistical copolymers, poly[(2-(3-thienyl)ethanol n-butoxycarbonylmethylurethane)-co-3-hexylthiophene] (PURET-co-P3HT), were synthesized by the chemical dehydrogenation method using anhydrous $FeCl_3$. The structure and electro-optical properties of these copolymers were characterized using $^1H$-NMR, UV-visible spectroscopy, elemental analysis, GPC, DSC, TGA, photoluminescence (PL), and cyclic voltammetry (CV). The statistical copolymers, PURET-co-P3HT (1:0, 2:1, 1:1, 1:2, 1:3), were soluble in common organic solvents and easily spin coated onto indium-tin oxide (ITO) coated glass substrates. Hybrid bulk heterojunction photovoltaic cells with an ITO/G-PEDOT/PURET-co-P3HT:PCBM:Ag nanowires/$TiO_x$/Al configuration were fabricated, and the photovoltaic cells using PURET-co-P3HT (1:2) showed the best photovoltaic performance compared with those using PURET-co-P3HT (1:0, 2:1, 1:1, 1:3). The optimal hybrid bulk heterojunction photovoltaic cell exhibits a power conversion efficiency (PCE) of 1.58% ($V_{oc}$ = 0.82 V, $J_{sc}$ = 5.58, FF = 0.35) with PURET-co-P3HT (1:2) measured by using an AM 1.5 G irradiation (100 mW/$cm^2$) on an Oriel Xenon solar simulator (Oriel 300 W).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.9
• /
• pp.4334-4356
• /
• 2017

In orthogonal frequency-division multiplexing (OFDM) systems, phase noise introduced by the local oscillators can cause bit error rate (BER) performance degradation. To solve the phase noise problem, a novel orthogonal-polarization-based phase noise self-cancellation (OP-PNSC) scheme is proposed. First, the efficiency of canceling the phase noise of the OP-PNSC scheme in the AWGN channel is investigated. Then, the OP-PNSC scheme in the polarization-dependent loss (PDL) channel is investigated due to power imbalance caused by PDL, and a PDL pre-compensated OP-PNSC (PPC -OP-PNSC) scheme is proposed to mitigate the power imbalance caused by PDL. In addition, the performance of the PPC-OP-PNSC scheme is investigated, where the signal-to-interference-plus-noise ratio (SINR) and spectral efficiency (SE) performances are analyzed. Finally, a comparison between the OP-PNSC and polarization diversity scheme is discussed. The numerical results show that the BER and SINR performances of the OP-PNSC scheme outperform the case with the phase noise compensation and phase noise self-cancellation scheme.

• Annual Conference on Human and Language Technology
• /
• 2003.10d
• /
• pp.54-60
• /
• 2003

음차 표기된 외래어로부터 원어를 복원하는 문제는 원어의 발음정보를 이용한 통계적인 방법을 많이 사용한다. 하지만 지금까지의 연구들은 대부분 영어단어만을 그 대상으로 하였기 때문에 '도쿄(Tokyo)', '하인리히(Hinrich)'와 같이 어원이 영어가 아닌 단어들의 복원에는 좋은 결과를 보여주지 못했다. 이러한 문제를 해결하기 위하여 한글로 표기된 외래어의 어원을 판단할 수 있는 방법을 찾아내고, 이 방법을 통해 외래어를 어원별로 분리하여 학습모델을 구축함으로써 다양한 어원을 가진 외래어들의 복원 정확률을 높이고자 하였다. 위의 방식으로 구현된 시스템은 영어, 일본어, 중국어, 프랑스어의, 서로 다른 4개의 어원을 가진 데이터의 복원 실험에서 기존의 방식에 비해 13%의 성능 향상을 보였다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06a
• /
• pp.154-157
• /
• 2011

본 연구는 2인의 전문의와 함께 의료 문헌의 초록을 분석하여 의료문서에서의 절차적 지식을 모델링하고 텍스트 마이닝 기법을 적용하여 절차적 지식을 추출하는 방법론에 대해 기술한다. 절차적 지식은 목적과 해법의 묶음으로, 해법은 다시 단위 절차 지식의 네트워크로 정의 하였고, 목적과 해법 정보 추출과 단위 절차 지식의 구성요소인 대상/행위/방법 개체를 인식하기 위해, 품사태깅, 구문분석, 술어-논항구조(Predicate-Argument Structure), 온톨로지 용어 매핑 정보 등에 기반한 기계학습 방법을 사용하였다. 실험을 위해 전문의와 함께 위함과 척추질환에 대한 1309 문서에 절차적 지식 태깅을 수행하였고, 이 문서 집합을 기반으로 목적/해법 추출 작업과 단위 절차 지식(대상질병/행위/적용방법) 추출 실험을 수행하여, 각각 82% 와 63%의 F-measure 값을 얻을 수 있었다.

• Journal of the Korea Safety Management & Science
• /
• v.14 no.2
• /
• pp.159-166
• /
• 2012

As enterprises, based on the forecast of the customer's demand and collaboration with the suppliers, establish the integrated system directing supply, production, and distribution for the increase of productivity, Thus, this study intends to find the most urgent and critical factors for the improvement of the information system by externalizing factors affecting the operation of information system, suggest the process to improve the relevant functions of information system, and design the process. As a result of the analysis of the previous studies on the improvement of the information system, many studies were conducted on the improvement of ERP and SCM, yet there was no study conducted targeting about APS (Advanced Planning & Scheduling). Thus, this study chose APS as the subject for the design of the process for the improvement for the information system.

• Annual Conference on Human and Language Technology
• /
• 2006.10e
• /
• pp.32-39
• /
• 2006

본 논문은 한국어정보처리 과정에서 구문 관계를 의미 관계로 사상하는 의미역 결정 문제에 대해 다루고 있다. 한국어의 경우 대량의 학습 말뭉치를 구하기 힘들며, 이를 구축하기 위해서는 많은 시간과 노력이 필요한 문제점이 있다. 따라서 본 논문에서는 학습 말뭉치를 직접 태깅하지 않고 격틀사전을 이용하여 자동으로 학습 말뭉치를 구축하고 간단한 확률모델을 적용하여 점진적으로 모델을 학습하는 수정된 self-training 알고리즘을 사용하였다. 실험 결과, 4개의 부사격 조사에 대해 평균적으로 81.81%의 정확률을 보였으며, 수정된 self-training 방법은 기존의 방법에 비해 성능 및 실행시간에서 개선된 결과를 보였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.8
• /
• pp.2764-2782
• /
• 2021

Existing city-level boundary nodes identification methods need to locate all IP addresses on the path to differentiate which IP is the boundary node. However, these methods are susceptible to time-delay, the accuracy of location information and other factors, and the resource consumption of locating all IPes is tremendous. To improve the recognition rate and reduce the locating cost, this paper proposes an algorithm for city-level boundary node identification based on bidirectional approaching. Different from the existing methods based on time-delay information and location results, the proposed algorithm uses topological analysis to construct a set of candidate boundary nodes and then identifies the boundary nodes. The proposed algorithm can identify the boundary of the target city network without high-precision location information and dramatically reduces resource consumption compared with the traditional algorithm. Meanwhile, it can label some errors in the existing IP address database. Based on 45,182,326 measurement results from Zhengzhou, Chengdu and Hangzhou in China and New York, Los Angeles and Dallas in the United States, the experimental results show that: The algorithm can accurately identify the city boundary nodes using only 20.33% location resources, and more than 80.29% of the boundary nodes can be mined with a precision of more than 70.73%.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.11
• /
• pp.5588-5613
• /
• 2018

Virtualization technology has been widely applied in the area of computer security research that provides a new method for system protection. It has been a hotspot in system security research at present. Virtualization technology brings new risk as well as progress to computer operating system (OS). A multi-level perception security model using virtualization is proposed to deal with the problems of over-simplification of risk models, unreliable assumption of secure virtual machine monitor (VMM) and insufficient integration with virtualization technology in security design. Adopting the enhanced isolation mechanism of address space, the security perception units can be protected from risk environment. Based on parallel perceiving by the secure domain possessing with the same privilege level as VMM, a mechanism is established to ensure the security of VMM. In addition, a special pathway is set up to strengthen the ability of information interaction in the light of making reverse use of the method of covert channel. The evaluation results show that the proposed model is able to obtain the valuable risk information of system while ensuring the integrity of security perception units, and it can effectively identify the abnormal state of target system without significantly increasing the extra overhead.