• Geomechanics and Engineering
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• 제31권4호
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• pp.339-352
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• 2022

Studying slope stability is an important branch of civil engineering. In this way, engineers have employed machine learning models, due to their high efficiency in complex calculations. This paper examines the robustness of various novel optimization schemes, namely equilibrium optimizer (EO), Harris hawks optimization (HHO), water cycle algorithm (WCA), biogeography-based optimization (BBO), dragonfly algorithm (DA), grey wolf optimization (GWO), and teaching learning-based optimization (TLBO) for enhancing the performance of adaptive neuro-fuzzy inference system (ANFIS) in slope stability prediction. The hybrid models estimate the factor of safety (F_S) of a cohesive soil-footing system. The role of these algorithms lies in finding the optimal parameters of the membership function in the fuzzy system. By examining the convergence proceeding of the proposed hybrids, the best population sizes are selected, and the corresponding results are compared to the typical ANFIS. Accuracy assessments via root mean square error, mean absolute error, mean absolute percentage error, and Pearson correlation coefficient showed that all models can reliably understand and reproduce the F_S behavior. Moreover, applying the WCA, EO, GWO, and TLBO resulted in reducing both learning and prediction error of the ANFIS. Also, an efficiency comparison demonstrated the WCA-ANFIS as the most accurate hybrid, while the GWO-ANFIS was the fastest promising model. Overall, the findings of this research professed the suitability of improved intelligent models for practical slope stability evaluations.

• Asia Marketing Journal
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• 제7권2호
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• pp.47-69
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• 2005

기술의 발달에 힘입어 업그레이드된 휴대폰이 매우 활발하게 출시되고 있고, 번호이동성 제도가 도입되면서 휴대폰 교체수요가 급증하고 있다. 이동통신 서비스와 휴대폰 단말기의 상호 보완관계는 매우 크다고 할 수 있는데, 고객들이 고사양의 최신 휴대폰으로 업그레이드 할 경우 다양한 서비스의 이용이 가능하여 인당서비스수익(ARPU)의 증대도 기대할 수 있다. 이와 같이 이동통신 서비스 제공자의 입장에서 자신이 보유하고 있는 서비스 이용행태 자료들을 활용하여 고객들의 신규 단말기 구매시점을 예측할 수 있다면 이는 매우 유용한 전략적 정보가 될 것이다. 즉 교체구매에 대한 소비자의 행동을 이해하여 조기수용자 층을 공략할 수도 있고 단말기 교체시기를 관리하여 서비스 관계를 강화할 수 있다. 본 연구에서는 이동통신 서비스 제공자가 보유하고 있는 고객의 서비스 이용행태 자료만을 활용하여, 휴대폰 사용자가 신제품으로 교체구매를 하는데 소요되는 기간에 영향을 주는 변수들 즉 혁신적 서비스 사용, 부가서비스 사용경험, 통화서비스 사용정도, 로열티 프로그램 참여 등의 효과를 분석하고 휴대폰 교체시기를 예측하는 모형을 개발하여 실증적으로 검증하였다. 변수들의 효과에 대한 가설 검증 결과는 다양한 실무적 시사점을 제공하고 있으며, 모형의 예측타당성도 입증되었다.

• 한국심리학회지 : 문화 및 사회문제
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• 제24권3호
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• pp.429-449
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• 2018

본 연구에서는 개인자존감을 통제한 상태에서 성별집단자존감이 성차별경험과 정당한 세상에 대한 믿음(Belief in a just world; 이하 BJW)간의 관계를 조절하는지 살펴보았다. 이를 위해 수도권에 거주하는 300명의 일반 여성을 대상으로 성차별경험, 개인자존감, 성별집단자존감, BJW를 측정하였고, 위계적 회귀분석을 실시하였다. 그 결과, 개인자존감을 통제한 상태에서, 성별집단자존감이 성차별경험과 BJW간의 관계를 조절하는 것으로 나타났다. 즉, 성별집단자존감이 높을수록, 성차별경험이 BJW에 미치는 부정적 영향이 감소하는 것으로 확인되었다. 또한, 성별집단자존감의 하위유형(멤버쉽, 사적, 공적, 정체성)이 각각 성차별경험과 BJW 간의 관계를 조절하는지 살펴보았는데, 그 결과, 정체성을 제외한 나머지 하위유형의 조절효과가 유의한 것으로 확인되었다. 본 연구의 결과를 바탕으로 본 연구의 한계점, 후속연구를 위한 제언, 그리고 상담적 함의를 논의하였다.

• 한국심리학회지 : 문화 및 사회문제
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• 제18권2호
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• pp.191-213
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• 2012

본 연구는 노인과 대학생을 대상으로 노인에 대한 명시적 및 암묵적 태도가 연령 및 성별에 따라 어떠한 차이가 있는지 검증해보고자 하였다. 남녀 대학생 64명과 남녀 노인 64명을 대상으로 명시적 태도검사, 명시적 선호도검사와 암묵적 연합검사(IAT)를 사용하여, 노인에 대한 태도를 살펴보았다. 분석 결과, 대학생은 명시적 및 암묵적 수준 모두에서 젊은이를 더 선호하는 내집단 선호를 보인 반면, 노인의 경우에는 두 수준 모두에서 젊은이를 더 선호하는 외집단 선호를 보였으나 두 집단 모두에서 노인에 대한 명시적 및 암묵적 태도 간에는 유의미한 상관관계가 나타나지 않았다. 이에 더해, 성별 및 연령에 따른 노인에 대한 태도에서 차이가 나타났는데, 명시적 수준에서는 노인에 비해 대학생들이 노인을 더 선호하고 신뢰하는 것으로 나타난 반면, 암묵적 수준에서는 남성의 경우에는 노인이 대학생보다 노인을 더 선호하고, 여성의 경우에는 대학생 이 노인에 비해 노인을 더욱 선호하는 것으로 나타났다. 본 연구의 결과를 토대로 노인에 대한 태도를 이론 및 실제적인 측면에서 논의하였고, 마지막으로 연구의 함의 및 제한점을 역시 기술하였다.

• 대한통합의학회지
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• 제11권4호
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• pp.291-298
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• 2023

Purpose : Although Korea's health insurance system and access to medical care are well established compared to other countries, the rate of non-fulfillment of dental treatment is high. Medical use rates can be affected by economic characteristics, individual heatlh condtions, health concerns, and health behaviors. This study was implemented to investigate the effect of the middle-aged elderly people's family living together on the dental examination rate and to use it as basic data for program development, research, and poicies to promote oral health. Methods : Raw data from the 7th national health and nutrition survey conducted by the Korea centers for disease control and prevention (2016~2018) were used and analyzed using SPSS 21.0 Version (IBM, United States). Results : As a result of the study family types accroding to general characteristics, the more women are (p<.001), the higther the age (p<.001), the lower the hosehold income level (p<.001), the lower the educational background (p<.001), the more people who live in Eup-Myeon (p<.001) It was fouend that the rate of living alone was high. The dental examination rate according to general characteristics was related to age (p<.001), income (p<.001), and educational background (p<.001), and the higher the examination rate was in the same (p<.001), and the higher the family living together (p<.001). Factors influencing whether or not dental treatment was not performed were in the following order: household income (p<.001), age (p=.001), and family type (p=.017). Conclusion : The above results confirmed the relationship between family membership and dental examination rates, and measures such as the development and operation of participatory programs to improve public oral health by resolving medical inequality and enhancing health equity, and it is believed that the development of professional manpower and the operation of education and programs for professionals are necessary.

• 대기
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• 제33권5호
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• pp.531-548
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• 2023

We developed the Aviation Convective Index (ACI) for predicting deep convective area using the operational global Numerical Weather Prediction model of the Korea Meteorological Administration. Seasonally optimized ACI (ACI_SnOpt) was developed to consider seasonal variabilities on deep convections in Korea. Yearly optimized ACI (ACI_YrOpt) in Part 1 showed that seasonally averaged values of Area Under the ROC Curve (AUC) and True Skill Statistics (TSS) were decreased by 0.420% and 5.797%, respectively, due to the significant degradation in winter season. In Part 2, we developed new membership function (MF) and weight combination of input variables in the ACI algorithm, which were optimized in each season. Finally, the seasonally optimized ACI (ACI_SnOpt) showed better performance skills with the significant improvements in AUC and TSS by 0.983% and 25.641% respectively, compared with those from the ACI_YrOpt. To confirm the improvements in new algorithm, we also conducted two case studies in winter and spring with observed Convectively-Induced Turbulence (CIT) events from the aircraft data. In these cases, the ACI_SnOpt predicted a better spatial distribution and intensity of deep convection. Enhancements in the forecast fields from the ACI_YrOpt to ACI_SnOpt in the selected cases explained well the changes in overall performance skills of the probability of detection for both "yes" and "no" occurrences of deep convection during 1-yr period of the data. These results imply that the ACI forecast should be optimized seasonally to take into account the variabilities in the background conditions for deep convections in Korea.

• 대기
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• 제33권5호
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• pp.519-530
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• 2023

Deep convection can make adverse effects on safe and efficient aviation operations by causing various weather hazards such as convectively-induced turbulence, icing, lightning, and downburst. To prevent such damage, it is necessary to accurately predict spatiotemporal distribution of deep convective area near the airport and airspace. This study developed a new index, the Aviation Convective Index (ACI), for deep convection, using the operational global Unified Model of the Korea Meteorological Administration. The ACI was computed from combination of three different variables: 3-hour maximum of Convective Available Potential Energy, averaged Outgoing Longwave Radiation, and accumulative precipitation using the fuzzy logic algorithm. In this algorithm, the individual membership function was newly developed following the cumulative distribution function for each variable in Korean Peninsula. This index was validated and optimized by using the 1-yr period of radar mosaic data. According to the Receiver Operating Characteristics curve (AUC) and True Skill Score (TSS), the yearly optimized ACI (ACI_YrOpt) based on the optimal weighting coefficients for 1-yr period shows a better skill than the no optimized one (ACI_NoOpt) with the uniform weights. In all forecast time from 6-hour to 48-hour, the AUC and TSS value of ACI_YrOpt were higher than those of ACI_NoOpt, showing the improvement of averaged value of AUC and TSS by 1.67% and 4.20%, respectively.

• 경영정보학연구
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• 제22권4호
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• pp.135-161
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• 2020

블록체인과 가상통화 관련 시장의 성장과 함께 가상통화거래소는 하나의 신규 산업으로 성장하고 있다. 그러나, 가상통화에 대한 법·규제적 정의가 진행 중에 있어서 기존 산업과 다르게 규제기관의 관리감독을 받지 않고 있으며, 이에 따라 본 연구는 거래소 해킹 및 사고로 인한 사용자(가상통화 투자자)의 피해가 다수 보고되었다. 가상통화거래소에서 발생할 수 있는 피해를 개인정보 및 계정의 탈취로 인한 자산 피해와 사용자가 외부 사기사건 등에 연루되어 발생할 수 있는 피해로 구분하여 연관성이 높은 기능을 선행 사업자와 비교 분석하였다. 회원가입(KYC: Know Your Client), 로그인, 거래 추가인증은 선행 사업자와 유사한 수준이나, 이상거래탐지(FDS: Fraud Detection System), 법화 및 가상통화 자금세탁방지(AML: Anti-Money Laundering)는 미흡한 수준으로 조속한 개선이 필요할 것으로 파악되었다.

• 농촌계획
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• 제30권3호
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• pp.37-53
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• 2024

The purpose of this study is to analyze the effectiveness of an agriculture and rural development ODA project in southern Nepal's Terai region to improve food security, and to suggest appropriate project approaches to improve food security. The subject of the analysis is the KOICA-funded 'Inclusive Rural Development project', and a framework for analyzing food security was established based on the FAO's four pillars of food security, and indicators were proposed to measure the food security of project farmers. The data for this study were obtained from a survey of project beneficiary farmers and their control group, and the effects of the project on food security were measured using a a t-test analysis, difference-in-difference analysis, propensity score matching-linear regression combined model (PSM-OLS) and a propensity score matching-difference-in-difference combined model(PSM-DID). The results showed that, in general, the ODA project treatment group had significant improvements in each of the four pillars of food security (food availability, access, utilization, and stability). In addition, cooperative membership had a positive impact on food security improvements, and there were also differences in outcomes among different ethnic groups in the Terai region. The implications of this study are that the Korean government's ODA policy should set aside the food security sector and incorporate food security indicators to contribute to the improvement of food security in ODA partner countries, and that agricultural and rural development ODA projects should include food security indicators as performance indicators in their pre-planning to contribute to securing food security for vulnerable groups as food insecurity is higher among vulnerable groups.

• 수완나부미
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• 제16권2호
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• pp.185-211
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• 2024

Southeast Asian cities like Manila, the Philippines, and Singapore have witnessed economic, political, and cultural changes over the years, especially after periods of colonization. States control their urban fabric-that is, its organization, planning, and design of cities-and thus dictate the flow of capital and forces of labor. Urban poor settlements, an offshoot of capital accumulation, are (re)moved around these cities in accordance with governing visions of development. For populations that are forced into changes brought about by urban development, practices of remembering are also controlled by dominant powers. These "monuments" are established in/as spaces to oblige an image of membership into a society ruled by such powers. Nevertheless, alternate sites of remembering counter these monumental spaces. This paper takes an interest in two novels that feature such places. Liwayway Arceo's Canal de la Reina (1972) and Suchen Christine Lim's The River's Song (2013) both figure rivers in Manila and Singapore, respectively. The eponymous river is the central axis of Canal de la Reina, entangled in class conflict and swift urban change in post-Commonwealth Manila. In The River's Song, the famous Singapore River provides a refuge for reminiscing about Singapore before the city-state's independence. Comparing these novels to what Filipino comparatist Ruth Jordana Pison calls fictional "counter-memory," we argue that their rivers remember personal and embodied experiences eliminated from hegemonic accounts of the city. Thus, they function as what we call "counter-monuments" for the urban poor marginalized in the history of the Philippines and Singapore.