• Journal of Electrical Engineering and Technology
• /
• 제9권2호
• /
• pp.721-725
• /
• 2014

In this paper, we propose a fast adaptive power allocation method for an orthogonal frequency division multiple access (OFDMA) system that employs an adaptive modulation and coding (AMC) scheme. The proposed scheme aims to reduce the calculation complexity of greedy adaptive power allocation (APA), which is known as the optimal algorithm for maximizing the utility argument of power. Unlike greedy APA, which starts power allocation from "0", the proposed algorithm initially allocates a certain level of power determined by the water-filling scheme. We theoretically demonstrate that the proposed algorithm has almost the same capability of maximizing the utility argument as the greedy APA while reducing the number of operations by 2M, where M is the number of AMC levels.

• 한국언어정보학회지:언어와정보
• /
• 제17권2호
• /
• pp.67-91
• /
• 2013

This paper describes Korean Nominal Bank, a project that provides argument structure for instances of the predicative nouns in the Sejong parsed Corpus. We use the language resources of the Sejong project, so that the same set of data is annotated with more and more levels of annotation, since a new type of a language resource building project could bring new information of separate and isolated processing. We have based on the annotation scheme based on the Sejong electronic dictionary, semantically tagged corpus, and syntactically analyzed corpus. Our work also involves the deep linguistic knowledge of syntaxsemantic interface in general. We consider the semantic theories including the Frame Semantics of Fillmore (1976), argument structure of Grimshaw (1990) and argument alternation of Levin (1993), and Levin and Rappaport Hovav (2005). Various syntactic theories should be needed in explaining various sentence types, including empty categories, raising, left (or right dislocation). We also need an explanation on the idiosyncratic lexical feature, such as collocation and etc.

• 대한수학회지
• /
• 제46권4호
• /
• pp.691-699
• /
• 2009

In this paper, we establish a multiple existence result of T-periodic solutions for the semilinear parabolic boundary value problem with sublinear growth nonlinearities. We adapt sub-supersolution scheme and topological argument based on variational structure of functionals.

• 대한수학교육학회지:수학교육학연구
• /
• 제27권4호
• /
• pp.701-725
• /
• 2017

본 연구에서는 학생들이 스스로 대화에 참여하여 자신과 상대방 간의 생각을 나누는 과정, 즉 반성, 변화 및 설득해 가는 과정에서 논증 활동을 경험하는 기회를 가지는 것이 중요하다고 판단하여 수학 수업 시간에 학생들이 과제를 해결하는 과정에서 이뤄지는 논증 활동을 면밀히 살펴보고자 하였다. 또한, 논증 활동 요소 중 하나인 '반박'에 중점을 두어 학생들이 수학 과제를 해결하는 과정에서 나타나는 반박의 유형이 무엇인지, 또 논증 활동이 일어나는 상황에서 반박이 논증 요소 중 무엇을 목표로 하는지 살펴보고자 하였으며, 이때 Verheij(2005)가 제안한 다섯 가지 반박 유형에 기초하여 탐색하고자 하였다. 이를 위하여 중학교 3학년 4명의 학생들을 대상으로 두 개의 기하 과제 중심의 토론 수업을 약 50분씩 두 차례 진행하고, 한 차례 반 구조화된 면담을 실시하였다. 본 연구를 통하여 학생들의 논증 활동에서 반박 유형에 초점을 두고 논증 활동을 세밀하게 탐색해 봄으로써 논증 활동에 대한 보다 견고한 이해를 돕고자 하였다.

• 한국통신학회논문지
• /
• 제30권2B호
• /
• pp.11-20
• /
• 2005

Strict priority scheduling scheme is a good candidate for the implementation of service differentiation in an Internet because of simplicity in implementation and the capability to guarantee the delay requirement of the highest class of traffic. However, it is also blown that strict priority starves the lower-class traffic at the cost of prioritizing the higher-class traffic. The purpose of this work is to propose an analytic method which can estimate the average delay performance of Diffserv service architecture and shows that strict priority scheme does not sacrifice the lower class traffic over a diverse condition of the load. From the numerical experiments for three-class Diffserv network we validate our argument that strict priority scheme may be applied to a service differentiation scheme for the future Internet.

• 한국과학교육학회지
• /
• 제38권2호
• /
• pp.249-257
• /
• 2018

본 연구의 목적은 중학생들이 유전과 관련된 과학적 현상에 대한 설명 글쓰기에서 드러나는 개념 성취 수준을 살펴보고, 과학적 현상을 설명하기 위해 어떠한 논변 구조와 정당화 방식을 사용하는지, 과학적 지식을 적절하게 정당화에 이용하고 있는지를 살펴보는 것이다. 이를 위해 서울시 소재 중학교 3학년 학생들 162명이 '유전과 진화'를 학습한 후에 크기와 모양이 같은 초록색 피망과 빨간색 피망이 같은 종류인지 다른 종류인지 다른 주장을 하는 경쟁 논변 중 하나를 선택하여 그 이유를 설명하도록 하였다. 연구 결과, 개념 성취 개념 성취 수준에서 전체 응답자(162명) 중 47%(77명)는 정답을, 53%(85명)는 오답을 제시하였다. 논변 수준을 살펴보면, 정답 학생들은 자료를 주장이나 결론에 연결하여 논거를 제시하는 수준인 수준 3(Constructing warrant)이 오답 학생들은 주장과 자료를 논리적으로 연결하지 않고 증거만 제시하는 수준인 수준 2(Providing evidence)가 가장 많았다. 정당화를 하면서 과학 지식(Scientific idea)의 사용을 학생들의 조사한 결과, 인과적 설명의 질을 결정할 수 있는 요소로 과학 지식을 사용한 학생 중 36%가 옳은 과학 지식(Correct scientific knowledge)을 사용하였으나, 나머지 학생들은 옳지 않은 과학 지식이나 특정되지 않은 과학 지식을 사용하였다. 이와 같은 연구 결과들은 인식적 실행인 과학적 현상을 설명하는 논변적 글쓰기를 장려하기 위해서 논변의 구조에 대한 영역 일반적인 지식의 교수 실행을 통해 관련된 특정 과학 지식을 적용하여 자신의 생각을 증거와 주장을 잘 연결할 수 있도록 훈련하는 것이 필요하다는 것을 강조한다.

• Journal of Information Processing Systems
• /
• 제10권4호
• /
• pp.618-627
• /
• 2014

Nowadays mobile users are using a popular service called Location-Based Services (LBS). LBS is very helpful for a mobile user in finding various Point of Interests (POIs) in their vicinity. To get these services, users must provide their personal information, such as user identity or current location, which severely risks the location privacy of the user. Many researchers are developing schemes that enable a user to use these LBS services anonymously, but these approaches have some limitations (i.e., either the privacy prevention mechanism is weak or the cost of the solution is too much). As such, we are presenting a robust scheme for mobile users that allows them to use LBS anonymously. Our scheme involves a client side application that interacts with an untrusted LBS server to find the nearest POI for a service required by a user. The scheme is not only efficient in its approach, but is also very practical with respect to the computations that are done on a client's resource constrained device. With our scheme, not only can a client anonymously use LBS without any use of a trusted third party, but also a server's database is completely secure from the client. We performed experiments by developing and testing an Android-based client side smartphone application to support our argument.

• 한국통신학회논문지
• /
• 제34권11B호
• /
• pp.1191-1199
• /
• 2009

As the Internet service evolves from the best effort data service to a multimedia service such as a mix of voice, data and video, a need for the guarantee of the quality of service to network services became one of the hot issues for the network operators. On the other hand, the introduction of the multimedia services over the IP network requires a managed differentiated service that adopts a prioritized treatment of packets. This incurs a need for a differentiated pricing scheme for the packets that receive different level of quality of service. This work proposes an analytic framework about packet pricing scheme for these services, and investigate the effect of service differentiation to the packet price for each class. Via numerical experiment, we validate our argument and illustrate the implication of the work.

• International Journal of Computer Science & Network Security
• /
• 제23권7호
• /
• pp.49-60
• /
• 2023

The amount of data generated by electronic systems through e-commerce, social networks, and data computation has risen. However, the security of data has always been a challenge. The problem is not with the quantity of data but how to secure the data by ensuring its confidentiality and privacy. Though there are several research on cloud data security, this study proposes a security scheme with the lowest execution time. The approach employs a non-linear time complexity to achieve data confidentiality and privacy. A symmetric algorithm dubbed the Non-Deterministic Cryptographic Scheme (NCS) is proposed to address the increased execution time of existing cryptographic schemes. NCS has linear time complexity with a low and unpredicted trend of execution times. It achieves confidentiality and privacy of data on the cloud by converting the plaintext into Ciphertext with a small number of iterations thereby decreasing the execution time but with high security. The algorithm is based on Good Prime Numbers, Linear Congruential Generator (LGC), Sliding Window Algorithm (SWA), and XOR gate. For the implementation in C, thirty different execution times were performed and their average was taken. A comparative analysis of the NCS was performed against AES, DES, and RSA algorithms based on key sizes of 128kb, 256kb, and 512kb using the dataset from Kaggle. The results showed the proposed NCS execution times were lower in comparison to AES, which had better execution time than DES with RSA having the longest. Contrary, to existing knowledge that execution time is relative to data size, the results obtained from the experiment indicated otherwise for the proposed NCS algorithm. With data sizes of 128kb, 256kb, and 512kb, the execution times in milliseconds were 38, 711, and 378 respectively. This validates the NCS as a Non-Deterministic Cryptographic Algorithm. The study findings hence are in support of the argument that data size does not determine the execution.

• 대한수학교육학회지:학교수학
• /
• 제18권1호
• /
• pp.85-103
• /
• 2016

이 연구는 5학년 영재반 수업에서 TI-73 그래핑 계산기의 지오보드를 사용하여 Pick의 공식을 찾아가는 과정에서 나타난 수업담화로부터 논증과 논증활동의 특성을 알아보고자 하였다. 분석을 위한 자료는 수업 비디오, 음성녹음록, 활동지가 있으며 Toulmin의 논증 도식을 분석의 준거로 사용하였다. 연구 결과 그래핑 계산기의 지오보드는 주어진 조건의 다양한 격자다각형에 대한 넓이를 계산해줌으로써 실험과 관찰의 환경을 조성하고 '자료${\rightarrow}$주장'의 구성과 이의 정당화를 위한 보증, 지지, 한정어, 반박의 논증활동을 유발시키는 도구적 역할을 하였다. 경계점의 수와 내점의 수로 Pick의 공식을 유도할 때 '집단적 논증'의 방식이 나타났으며 교사는 논증활동을 지휘하는 역할, 지식을 판단하는 권위자의 역할을 하였다.