• 정보처리학회논문지B
• /
• 제10B권3호
• /
• pp.347-358
• /
• 2003

인간은 문서전체를 읽지 않고 대표적인 단어를 보는 것만으로 정치나 스포츠 등의 분야를 정확히 인지할 수 있다. 문서전체를 대상으로 하지 않고 부분텍스트에서 출현하는 소수의 단어정보에서 문서의 분야를 정확히 결정하기 위해 분야연상어의 구축은 중요한 연구과제이다. 인간이 미리 분야체계를 정의하고, 각 분야에 해당하는 문서를 인터넷이나 서적을 통해 수집한다. 본 논문은 수집문서의 분야를 정확히 지시하는 분야연상어를 수집하는 방법을 제안한다. 문서의 분야결정 시점을 고려하여 분야연상어의 수준과 안정성 랭크에 대하여 논의한다. 학습데이터에서 분야연상어 후보의 각 수준을 자동으로 결정하고, 컴퓨터가 제시하는 분야연상어의 수준, 안정성 랭크, 집중률, 빈도정보를 이용하여 단일 분야연상어를 수집하는 방법을 제안한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제49권2호
• /
• pp.68-74
• /
• 2023

Objectives: Drug holidays are suggested to reduce the formation of osteonecrosis in patients under intravenous (IV) bisphosphonates (BPs) therapy. The objectives of this study are to evaluate the incidence of medication-related osteonecrosis of the jaw (MRONJ) following tooth extraction in cancer patients using IV BP, and to assess the effect of drug holiday on the development of MRONJ. Patients and Methods: A manuel search of the patient folders of Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Hacettepe University was undertaken to identify cancer patients who used IV BPs and had at least one tooth extraction between 2012 and 2022. Patents' age, sex, systemic condition, the type of BP used, duration of BP used, number of tooth extraction, duration of drug holiday, localization of tooth extraction and incidence of MRONJ were recorded. Results: One hundred nine teeth were removed from 57 jaws in 51 patients. All tooth extractions were performed under perioperative antibiotic prophylaxis and with primary wound closure. The incidence of MRONJ was 5.3%. Stage 1 MRONJ developed in 3 patients (only one had a drug holiday). The median duration of drug holiday was 2 months. No significant difference between the patients with and without a drug holiday and MRONJ development was found (P=0.315). The mean age of patients developed MRONJ was 40.33±8.08 years. A statistically significant difference was found between age and MRONJ development (P=0.002). Conclusion: The effect of a short-term drug holiday on the development of MRONJ may be limited because BPs remain in bone tissue for a long time. Drug holidays should be applied with the approval of an oncologist with other preventive measurements.

• 한국항행학회논문지
• /
• 제19권4호
• /
• pp.338-344
• /
• 2015

국가 직무능력 표준 (NCS; national competency standards)은 직무를 수행하기 위해 요구되는 능력에 대한 체계화 및 표준화이다. NCS는 특정 직무능력인 능력단위 요소로 구체화하고 표준화하여 학습모듈을 개발한다. 기존 교육과정은 NCS 능력단위 요소를 교육 훈련에 활용하기 위해서 갭 분석 (gab analysis)이 필수적이다. 기존에 갭 분석은 전문가가 주관적으로 평가하였다. 전문가에 의한 갭 분석은 심리적 요소에 의해 주관적 결정, 정확성 결여, 시간 및 공간적 비효율성 문제가 제기되었다. 본 논문은 주관적 평가의 문제 해결을 위해 자동화 평가모델을 제시하였다. 본 논문은 기존 교육과정과 능력단위 요소 간 갭 분석을 위해, 색인어 추출, 단어빈도수-역 빈도수 기반 특징 값 추출, 코사인 유사도 알고리즘을 이용하였다. 또한, 기존 교육과정과 NCS 능력단위요소 사이 유사도 매핑 테이블을 제시하였다. 본 논문의 평가모델은 구조적 특징이나 속도 면에서 개선된 알고리즘을 통해 보완해야 한다.

• 한국산업정보학회논문지
• /
• 제29권3호
• /
• pp.51-65
• /
• 2024

스마트 그리드에서 전력 시스템을 효과적으로 운영하기 위해서는 전력 수요량을 정확히 예측하는 것이 중요하다. 최근 기계학습 기술의 발달로, 인공지능 기반의 전력 수요량 예측 모델이 활발히 연구되고 있다. 하지만, 기존 모델들은 모든 입력변수를 수치화하여 입력하기 때문에, 이러한 수치들 사이의 의미론적 관계를 반영하지 못해 예측 모델의 정확도가 하락할 수 있다. 본 논문은 입력 데이터에 대하여 거대언어모델을 통해 추출한 특징을 이용하여 단기 전력 수요량을 예측하는 기법을 제안한다. 먼저, 입력변수를 문장 형식의 프롬프트로 변환한다. 이후, 가중치가 동결된 거대언어모델을 이용하여 프롬프트에 대한 특징을 나타내는 임베딩 벡터를 도출하고, 이를 입력으로 받은 모델을 학습하여 예측을 수행한다. 실험 결과, 제안 기법은 수치형 데이터에 기반한 예측 모델에 비해 높은 성능을 보였고, 프롬프트에 대한 거대언어모델의 주의집중 가중치를 시각화함으로써 예측에 있어 주요한 영향을 미친 정보를 확인하였다.

• 응용통계연구
• /
• 제32권2호
• /
• pp.265-276
• /
• 2019

문서-용어 빈도행렬은 텍스트 마이닝에서 분석하고자 하는 개체 정보를 가지고 있는 일반적인 자료 형태이다. 본 연구에서 문서 분류를 위해 문서-용어 빈도행렬에 적용되는 기존의 용어 가중치인 TF-IDF를 소개한다. 추가하여 최근에 알려진 용어 가중치인 TF-IDF-ICSDF와 TF-IGM의 정의와 장단점을 소개하고 비교한다. 또한 문서 분류 분석의 질을 높이기 위해 핵심어를 추출하는 방법을 제시하고자 한다. 추출된 핵심어를 바탕으로 문서 분류에 있어서 가장 많이 활용된 기계학습 알고리즘 중에서 서포트 벡터 머신을 이용하였다. 본 연구에서 소개한 용어 가중치들의 성능을 비교하기 위하여 정확률, 재현율, F1-점수와 같은 성능 지표들을 이용하였다. 그 결과 TF-IGM 방법이 모두 높은 성능 지표를 보였고, 텍스트를 분류하는데 있어 최적화 된 방법으로 나타났다.

• Journal of Periodontal and Implant Science
• /
• 제42권5호
• /
• pp.158-165
• /
• 2012

Purpose: Recent interest has focused on intentional replantation to restore an original tooth. Some studies have shown successful results with intentional replantation for periodontally involved teeth. For long-term success of replantation, a healthy periodontal status of the recipient site is required so that delayed replantation is more suitable for periodontally involved teeth. To reveal the ideal timing for delayed replantation of periodontally involved teeth, the healing process of extraction sockets after extraction of periodontitis-induced teeth in rats was evaluated. Methods: Twenty-eight rats were randomly divided into two groups: a control group (n=8) and test group (n=20). In the test group, periodontitis was induced by a ligature around the cervix of the mandibular first molar of all of the rats. Two weeks later, the mandibular first molars were extracted in all of the animals. The animals were sacrificed on days 0, 3, 7, and 10 after extraction and histological and immunohistochemical analysis was performed. Results: In histological analysis of the test group, inflammatory cell infiltrate was found abundantly in the remaining periodontium 3 days after tooth extraction and decreased gradually at later time points. In immunohistochemical analysis of the test group, both interleukin-6 (IL-6) and, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) were numerous in the furcation area at each postextraction day. IL-6 was stained more heavily between 3 and 7 days after extraction; at day 10 after extraction, little staining was observed. TNF-${\alpha}$ staining was more intense at 3 days after extraction and gradually weakened at later points in time. Conclusions: Within the limits of this study, it takes at least 10 days to resolve periodontal inflammation in rat extraction sockets.

• 한국항해항만학회지
• /
• 제36권9호
• /
• pp.741-751
• /
• 2012

This article analyzes the interdependency between nonrenewable marine sand resources and renewable fishery resources by the developed dynamic bioeconomic model. The developed bioeconomic model is applied to a case study of efficient sustainable management for marine sand mining, which adversely affects a valuable blue crab fishery and its habitat in Korea. The socially-efficient extraction plan for marine sand and the time-variant environmental external costs to society in terms of diminished harvest rate of blue crab are determined. To take into account long-term effects from destroyed fishery habitat, a Beverton-Holt age structure model is integrated into the bioeconomic model. The illustrative results reveal that the efficient sand extraction plan is dynamically constrained by the stock size of the blue crab fishery over time. Thus, the dynamic environmental external cost is more realistic resource policy option than the classical fixed external cost for determining socially optimal extraction plans. Additionally, the economic value of bottom habitat, which supports the on- and off-site commercial blue crab fishery is estimated. The empirical results are interpreted with emphasis on guidelines for management policy for marine sand mining.

• Nuclear Engineering and Technology
• /
• 제47권5호
• /
• pp.579-587
• /
• 2015

To support the use of nuclear power as a sustainable electric energy generating technology, long-term supply of uranium is very important. The objective of this research is to investigate the use of new adsorbent material for cost effective uranium extraction from seawater. An activated carbon-based adsorbent material is developed and tested through an electrosorption technique in this research. Adsorption of uranium from seawater by activated carbon electrodes was investigated through electrosorption experiments up to 300 minutes by changing positive potentials from +0.2V to +0.8V (vs. Ag/AgCl). Uranium adsorption by the activated carbon electrode developed in this research reached up to 3.4 g-U/kg-adsorbent material, which is comparable with the performance of amidoxime-based adsorbent materials. Electrosorption of uranium ions from seawater was found to be most favorable at +0.4V (vs. Ag/AgCl). The cost of chemicals and materials in the present research was compared with that of the amidoxime-based approach as part of the engineering feasibility examination.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
• /
• pp.117-120
• /
• 2001

In this work, we propose a new method of extracting and weighting representative keywords(RKs) from a few documents that might interest a user. In order to extract RKs, we first extract candidate terms and then choose a number of terms called initial representative keywords (IRKS) from them through fuzzy inference. Then, by expanding and reweighting IRKS using term co-occurrence similarity, the final RKs are obtained. Performance of our approach is heavily influenced by effectiveness of selection method of IRKS so that we choose fuzzy inference because it is more effective in handling the uncertainty inherent in selecting representative keywords of documents. The problem addressed in this paper can be viewed as the one of calculating center of document vectors. So, to show the usefulness of our approach, we compare with two famous methods - Rocchio and Widrow-Hoff - on a number of documents collections. The results show that our approach outperforms the other approaches.

• Journal of Dental Anesthesia and Pain Medicine
• /
• 제15권4호
• /
• pp.241-245
• /
• 2015

A majority of patients who sustain injuries to the peripheral sensory nerves of the face and jaws experience a slow but gradual return of sensation that is functional and tolerable, if not the same as before the injuries. However, long-term effects of such injuries are aggravating for many patients, and a few patients experience significant suffering. In some of these patients, posttraumatic symptoms become pathological and are painful. The predominant painful components are (1) numbing anesthesia dolorosa pain, (2) triggered neuralgiaform pain, (3) burning and aching causalgiaform pain, and (4) phantom pain. This is a case report of conservative management of traumatic neuralgia and neuritis as part of posttraumatic pain syndromes in geriatric patients who have undergone the teeth extraction and alveoloplasty.