• The KIPS Transactions:PartB
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• v.9B no.5
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• pp.689-700
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• 2002

In this paper, we developed Korean Morphological Analyzer for an automatic indexing that is essential for Information Retrieval. Since it is important to index large-scaled document set efficiently, we concentrated on maximizing the speed of word analysis, modularization and structuralization of the system without new concepts or ideas. In this respect, our system is characterized in terms of software engineering aspect to be used in real world rather than theoretical issues. First, a dictionary of words was structured. Then modules that analyze substantive words and inflected words were introduced. Furthermore numeral analyzer was developed. And we introduced an unknown word analyzer using the patterns of morpheme. This whole system was integrated into K-2000, an information retrieval system.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.3
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• pp.208-214
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• 2021

Recently, much of the intelligent security scenario and criminal investigation demands for matching photo and non-photo. Existing face recognition system can not sufficiently guarantee these needs. In this paper, we propose an algorithm to improve the performance of heterogeneous face recognition systems by reducing the different modality between sketches and photos of the same person. The proposed algorithm extracts each image's texture features through texture descriptors (gray level co-occurrence matrix, multiscale local binary pattern), and based on this, generates a transformation matrix through eigenfeature regularization and extraction techniques. The score value calculated between the vectors generated in this way finally recognizes the identity of the sketch image through the score normalization methods.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.5
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• pp.791-805
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• 2022

In recent years, the number of scams related to voice phishing has been on the decline, but the number of messenger phishing attacks, a new type of crime, is increasing. In this study, by analyzing SNS posts containing messenger phishing cases, criminal trends of the main methods, imposture of trusted relative and fake payment were identified. Through the analysis, main words and patterns composing the message and the similarity and continuity of the phone numbers used were derived as criminal attributes, and criminal organizations were grouped. As the results of the analysis, we propose a cooperative system to prevent damage from messenger phishing by disseminating the criminal information collected by investigative agencies to private operators, and a plan to respond to messenger phishing predicted through grouping of criminal organizations.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.23-28
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• 2023

Windows operating system generates various logs with timestamps. Timestamp tampering is an act of anti-forensics in which a suspect manipulates the timestamps of data related to a crime to conceal traces, making it difficult for analysts to reconstruct the situation of the incident. This can delay investigations or lead to the failure of obtaining crucial digital evidence. Therefore, various techniques have been developed to detect timestamp tampering. However, there is a limitation in detection if a suspect is aware of timestamp patterns and manipulates timestamps skillfully or alters system artifacts used in timestamp tampering detection. In this paper, a method is designed to detect changes in timestamps, even if a suspect alters the timestamp of a file on a storage device, it is challenging to do so with precision beyond millisecond order. In the proposed detection method, the first step involves verifying the timestamp of a file suspected of tampering to determine its write time. Subsequently, the confirmed time is compared with the file size recorded within that time, taking into consideration the performance of the storage device. Finally, the total capacity of files written at a specific time is calculated, and this is compared with the maximum input and output performance of the storage device to detect any potential file tampering.

• Korean Security Journal
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• no.61
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• pp.377-400
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• 2019

Photography is the most commonly used method of documenting the crime and incident scene as it helps maintaining chain of custody (COC) and prove integrity of the physical evidence. It can also capture phenomena as they are. However, digital images can be manipulated and lose their authenticity as admissible evidence. Thus only limited techniques can be used to enhance images, and one of them is Fourier transform. Fourier transform refers to transformation of images into frequency signals. Fast Fourier transform (FFT) is used in this study. In this experiment, we overlapped fingerprints with graph paper or other fingerprints and separated the fingerprints. Then we evaluated and compared quality of the separated fingerprints to the original fingerprints, and examined whether the two fingerprints can be identified as same fingerprints. In the case of the fingerprints on graph paper and general pattern-overlapping fingerprints, fingerprint ridges are enhanced. On the other hand, in case of separating complicated fingerprints such as core-to-core overlapping and delta-to-delta overlapping fingerprints, quality of fingerprints can be deteriorated. Quality of fingerprints is known to possibly bring negative effects on the credibility of examiners. The result of this study may be applicable to other areas using digital imaging enhancement technology.

• Strategy21
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• s.43
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• pp.273-302
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• 2018

1980년대 북 핵개발을 처음 발견 이후, 미국은 북한의 비핵화라는 정책목적달성을 위해 다양한 정책을 사용해 왔지만 현재까지 실패하였다. 미국의 대북 정책 실패의 결과는 북핵 문제의 고착화 속에서, 평양의 핵무기 개발 가속화 야기로 한반도 및 미국을 핵위협 속에 놓이게 하였다. 특히, 지난 해, 북미간의 가열된 공격적 수사와 행동에 의한 한반도 위기설은 절정에 달하였다. 해결의 실마리가 보이지 않던 한반도의 갈등 및 위기는, 지난 4월에 열린 남북 정상회담을 통해 25년간의 핵위협의 굴레를 벗어날 기회를 다시 한번 맞이하게 되었다. 남북 정상회담 이후 이어질 북미 정상회담 등 향후 미국의 정책은 한반도 비핵화를 위한 중요한 분수령에 다시 한번 서있다. 하지만, 과거의 25년간의 역사는 다시 맞이한 '한반도의 봄'에 대한 낙관적 희망만을 주지 않는다. 과거, 양자적, 다자적 협상을 이룸에도 불구하고, 북핵 문제는 다시 위기에 접어드는 반복된 패턴과 사이클 속에 악화 되어 왔기 때문이다. 비핵화의 분수령에 있는 미 정부는 다시 한번 과거의 정책을 뒤돌아 보고, 남북 정상회담을 통해 어렵게 맞이한 기회를 결실로 이룰 수 있도록 어느 때 보다 신중한 노력이 필요하다. 최근 몇 달간 북핵 문제는 경이로운 속도로 진전을 보였지만, 한순간의 정책의 실패는 최근 보여진 진전의 속도 이상의 속도로 문제를 악화 시킬 수 있으며, 그 결과는 작년 여름과 겨울의 위기보다 더욱 심각 할 수 있음을 명심해야 한다. 이러한 점에서 이 보고서는 과거의 역사 및 이론적 분석을 통해 과거 미국의 북핵정책 실패 원인을 분석하고 정책을 제언하는데 그 목적이 있다. 과거 미 북핵 실패의 원인은 크게 3가지로 보인다. 먼저, 포괄적인 그리고 북한 정권의 특성에서 비롯된 북핵 개발의 모티브를 정확히 이해하는데 실패하여, 북한의 정책적 계산을 변화 시키는데 실패 하였다. 둘째, 북한 문제를 둘러싼 외부적 복잡성이 미북핵 정책실패를 야기하였다. 한반도 문제는 과거부터 다양한 국가들의 이해관계에 둘러 싸여 왔다. 북핵 문제도 남북 및 미국을 비롯 중국 등 주변국의 복잡성이 불확실성을 가중시켜 문제를 더욱 복잡하게 하였으며, 미국의 대북 협상의 영향력을 약화 시켰다. 셋째, 과거 누적된 두 국가간의 불신은 협상 이후 상대의 신뢰 있는 이행에 대한 불신을 야기하여 미국의 정책의 효과성을 저해하였다. 미국은 북핵 개발 모티브에 대한 포괄적 이해와 한국 및 중국과의 다자외교로 과거의 실패를 극복하고 25년간의 북핵문제의 고리를 끊어야 할 것이다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.405-415
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• 2020

With the increase in smartphone user, mobile forensics has become an essential element in modern digital forensic investigation. Mobile messenger data is very important data in mobile forensics because it can acquire information such as user's life pattern and mental state. In order to analyze messenger data, a decryption technique of an encrypted messenger data is required. Since most messengers provide a message deleting function, a technique for recovering deleted messages is required. WeChat Messenger, a messenger used by about 1 billion people around the world, uses IMEI (International Mobile Equipment Identity) information to encrypt data and provides message deletion function. In this paper, we propose a data decryption method in the absence of IMEI information and propose a method for recovering deleted messages using FTS (Full Text Search) database created for full-text search function of SQLite database.

• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.99-105
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• 2023

In the 4th industrial revolution, the field of criminal justice is paying attention to Legaltech using artificial intelligence to provide efficient legal services. This paper attempted to create a crime prediction model that can apply Recurrent Neural Network(RNN) to increase the potential for using legal technology in the domestic criminal justice field. To this end, the crime process was divided into pre, during, and post stages based on the criminal facts described in the judgment, utilizing crime script analysis techniques. In addition, at each time point, the method and evidence of crime were classified into objects, actions, and environments based on the sentence composition elements and the 8 principles of investigation. The case summary analysis framework derived from this study can contribute to establishing situational crime prevention strategies because it is easy to identify typical patterns of specific crime methods. Furthermore, the results of this study can be used as a useful reference for research on generating crime situation prediction data based on RNN models in future follow-up studies.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.4
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• pp.250-258
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• 2021

This study was conducted to investigate the effect of feeding systems on feed intake, weight gain, and fawn performance (Cervus canadensis) and estimation of grazing intensity in Elk doe at pasture. A sixteen Elk doe about 236.2 kg were randomly assigned to two feeding treatments. The treatment consisted of a barn feeding system (BF) and grazing at pasture (GR), and pasture was mainly composed of tall fescue, orchard grass, and Kentucky bluegrass. The moisture content of pasture was 19.51~22.61%, which was similar during experimental periods. The crude protein content was significantly higher from June to July (p<0.05). The contents of neutral detergent fiber and acid detergent fiber ranged 53.65~60.18%, and 26.08~29.10%, respectively. There were no significant differences between feeding systems on supplementary feed intake, but the roughage and total dry matter intake showed significant differences between treatment groups (p<0.05), except for May. In August, roughage intake was dramatically decreased in the GR group due to summer environmental changes. On the other hand, the higher intake of roughage in September might be related to nutrient intake for mammals. There was no difference in body weight between treatment groups, but the fawn performance was significantly higher in the GR group (p<0.05). These results might be suggested that grazing elk doe might positively affect fawn growth. However, it is considered that BF might increase the deer weaning rate during the parturition period, since the lower weaning rate in the GR group compared to the BF group. The grazing intensity of Elk doe was increased from May to July and decreased in August, which was influenced by pasture productivity. The average grazing intensity of Elk doe was found to be 15 heads/ha, which might be controlled by supplementary feeding. Further studies needed that mixed sowing methods and fertilization management in old grazing pastures for improved pasture productivity.

• Journal of the Korean association of regional geographers
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• v.4 no.1
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• pp.27-41
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• 1998

The communication model has been accepted as the basic research paradigm of cartography since Board(1967) discussed the map/model analogy. In that paradigm, the function of maps was limited to the media of communication, and the functionality of maps was extremely emphasized. Therefore the model could not play its own role under the new environments such as computer, GIS, scientific visualization. Nowadays, the model has been attacked on several grounds and several alternatives have been suggested. Among the objections raised are (1) geographic visualization in which maps are considered as the tool of scientific visualization, (2) the contributions of art which are ignored in the positivist cartographic research, and (3) deconstructionist arguments which deny the scientific epistemology of map as an objective form of knowledge and recognize the textuality of maps including their metaphorical and rhetorical nature. Since a publication by McCormick et al, the scientific visualization based on the powerful computer graphics is used in a wide context. Maps are treated as the tools of scientific visualization and emphasis is on exploration of the geographic data to gain understanding and insight in the geographic visualization processes. The research on geographic visualization have stayed in the early stage of developing the conceptual model and the basic visualization tools. But, it is expected that the geographic or visual thinking which is emphasized in the geographic visualization will contribute the reestablishment of links between cartography and geography. Also, the development of scientific visualization tools and strategies will offer the opportunities to suggest a fresh idea, to synthesize information and develop holistic approaches to geographical problems.