• Journal of Intelligence and Information Systems
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• v.25 no.1
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• pp.139-161
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• 2019

The utilization of the e-commerce market has become a common life style in today. It has become important part to know where and how to make reasonable purchases of good quality products for customers. This change in purchase psychology tends to make it difficult for customers to make purchasing decisions in vast amounts of information. In this case, the recommendation system has the effect of reducing the cost of information retrieval and improving the satisfaction by analyzing the purchasing behavior of the customer. Amazon and Netflix are considered to be the well-known examples of sales marketing using the recommendation system. In the case of Amazon, 60% of the recommendation is made by purchasing goods, and 35% of the sales increase was achieved. Netflix, on the other hand, found that 75% of movie recommendations were made using services. This personalization technique is considered to be one of the key strategies for one-to-one marketing that can be useful in online markets where salespeople do not exist. Recommendation techniques that are mainly used in recommendation systems today include collaborative filtering and content-based filtering. Furthermore, hybrid techniques and association rules that use these techniques in combination are also being used in various fields. Of these, collaborative filtering recommendation techniques are the most popular today. Collaborative filtering is a method of recommending products preferred by neighbors who have similar preferences or purchasing behavior, based on the assumption that users who have exhibited similar tendencies in purchasing or evaluating products in the past will have a similar tendency to other products. However, most of the existed systems are recommended only within the same category of products such as books and movies. This is because the recommendation system estimates the purchase satisfaction about new item which have never been bought yet using customer's purchase rating points of a similar commodity based on the transaction data. In addition, there is a problem about the reliability of purchase ratings used in the recommendation system. Reliability of customer purchase ratings is causing serious problems. In particular, 'Compensatory Review' refers to the intentional manipulation of a customer purchase rating by a company intervention. In fact, Amazon has been hard-pressed for these "compassionate reviews" since 2016 and has worked hard to reduce false information and increase credibility. The survey showed that the average rating for products with 'Compensated Review' was higher than those without 'Compensation Review'. And it turns out that 'Compensatory Review' is about 12 times less likely to give the lowest rating, and about 4 times less likely to leave a critical opinion. As such, customer purchase ratings are full of various noises. This problem is directly related to the performance of recommendation systems aimed at maximizing profits by attracting highly satisfied customers in most e-commerce transactions. In this study, we propose the possibility of using new indicators that can objectively substitute existing customer 's purchase ratings by using RFM multi-dimensional analysis technique to solve a series of problems. RFM multi-dimensional analysis technique is the most widely used analytical method in customer relationship management marketing(CRM), and is a data analysis method for selecting customers who are likely to purchase goods. As a result of verifying the actual purchase history data using the relevant index, the accuracy was as high as about 55%. This is a result of recommending a total of 4,386 different types of products that have never been bought before, thus the verification result means relatively high accuracy and utilization value. And this study suggests the possibility of general recommendation system that can be applied to various offline product data. If additional data is acquired in the future, the accuracy of the proposed recommendation system can be improved.

• The Korean Journal of Archival Studies
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• no.35
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• pp.161-206
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• 2013

'Maeul' is a concept connoting a community. As a place where ordinary people's lives are planned and realized, Maeul is the foundation of their daily lives as well as a place where they work, rest and enjoy pastime activities. In Korea, however, most Maeul communities are dismantled while going though the modern period representing colonization and developmental dictatorship. Growth-oriented industrialization and urbanization turned into such adverse effects as individualization, a sense of loss and a sense of alienation. Recently, through innovations from below, Maeuls are restored, and through Maeul communities restored this way, every Maeul and many researchers carry out activities to build a healthy civil society. This study was conducted on such a background. For a healthy restoration of Maeul communities and a sustainable operation of those communities, it is necessary to establish archives where record the trace of Maeul members' daily lives and relations between those members. The archive of Maeul communities is a place that contains each Maeul's local characteristics as well as human relations as well. It is because this place can be space where Maeul members can record their history, communicate with each other and make a better future. The archive of Maeul communities can be made into various different models, which can be operated by reflecting the identity of a community such as main agents and characteristics, objectives and orientation of objects recorded. Rather than when Maeul communities exist as individuals, they can display more important functions and better effect when they form a network. Therefore, it is needed to provide various and creative methodologies different from the existing government-led record management. Not only on the form of archives, but also all over their functions, such as collection, arrangement, classification, evaluation, management and utilization, Maeul and Maeul residents' norms, orientation and realistic conditions should be thoroughly reflected. Starting from a chance to look back at individuals' lives, the archive of Maeul communities will be a new chapter to restore and build a healthy community in our society and overcome social contradictions from below. Moreover, the archive of Maeul communities has a great significance that it will broaden its prospect creatively with a new paradigm, not only mechanically turning the existing public sector-centered record management into a non-governmental sector.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.95-103
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• 2019

Temperature and relative humidity are important factors in crop cultivation and should be properly controlled for improving crop yield and quality. In order to control the environment accurately, we need to predict how the environment will change in the future. The objective of this study was to predict air temperature and relative humidity at a future time by using a multilayer perceptron (MLP). The data required to train MLP was collected every 10 min from Oct. 1, 2016 to Feb. 28, 2018 in an eight-span greenhouse ($1,032m^2$) cultivating mango (Mangifera indica cv. Irwin). The inputs for the MLP were greenhouse inside and outside environment data, and set-up and operating values of environment control devices. By using these data, the MLP was trained to predict the air temperature and relative humidity at a future time of 10 to 120 min. Considering typical four seasons in Korea, three-day data of the each season were compared as test data. The MLP was optimized with four hidden layers and 128 nodes for air temperature ($R^2=0.988$) and with four hidden layers and 64 nodes for relative humidity ($R^2=0.990$). Due to the characteristics of MLP, the accuracy decreased as the prediction time became longer. However, air temperature and relative humidity were properly predicted regardless of the environmental changes varied from season to season. For specific data such as spray irrigation, however, the numbers of trained data were too small, resulting in poor predictive accuracy. In this study, air temperature and relative humidity were appropriately predicted through optimization of MLP, but were limited to the experimental greenhouse. Therefore, it is necessary to collect more data from greenhouses at various places and modify the structure of neural network for generalization.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.30.1-30.1
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• 2018

일제 강점기를 지난 후 광복을 맞았지만, 전란의 폐허 속에 개설된 대학의 천문학과의 관측 시설들은 전문한 상태였다. 필자가 학부 재학 중이던 6-70년대까지도 시 시공(時空)의 흐름은 필요한 것을 직접 만들어 사용할 수밖에 없는 시대로 몰아가고 있었다. 당시를 회고 하며 지금까지 걸어 온 "천문기기 제작 연구의 삶"을 회고하고자 한다. 대학 재학 시절 교수님의 도움으로 막스토브 망원경을 제작하고, 40cm 카세그레인 망원경 등 광학계의 원리와 특성연구를 통해 부품 조립을 수행할 수 있었다. 태양 흑점관측을 위한 10cm 굴절 망원경의 투영시설을 고안하여 6개월 동안 관측하였지만. 석사 논문을 위해 광전측광 관측시스템을 제작하여 식쌍성 관측을 수행하였다. 그 결과 한국의 시설로 UBV 광도곡선 완성하여 1975년 가을 천문학회에서 발표하였다. 1976년 2월 국립천문대 천문계산연구실에 발령 받고 역서편찬 업무를 담당하면서 소백산 60cm 망원경 최종 설치를 끝내고, 천문대(현 역삼동 과총회관 빌딩) 옥상에 2m 규모의 목재 돔을 설계 제작하고 일반인들을 위한 대중천문 활동을 시작하였다. 재직 중에 항상 한국의 열악한 천문시설의 상황을 실감하고 20대를 마감하면서 퇴직하여 "한국천문기기 연구소"라는 명칭으로 천체 돔을 설계하고, 돔 제작기계를 개발하였다. 망원경만 보관 중인 국내 4개 대학에 돔을 납품 한 후 연세대학교 천문대의 직경 6m 스텐레스 돔을 제작하였다. 아울러 연세대 천문대 60cm망원경을 설치하면서 이 곳에 입사하여 관측 장비개발 연구와 관측에 전념하게 되었다. 재직 기간 중 대학의 배려로 카나다 국립천문대(DAO) 방문연구원으로 1.8m 망원경으로 식쌍성들의 분광관측을 수행하여 시선속도곡선을 완성하였고, 체류 중에 스텝들과 국내에서 사용할 60cm용 첨단 분광기를 설계하였으나 대학에 재원이 없어 제작을 못한 아쉬움이 남는다. 1989년 2월 충북대학교 천문우주학과에 부임하면서 열악한 상황이지만 교육과 연구 장비로 20cm와 35cm 소형 망원경의 디지털 광전측광시스템으로 간이 천문대를 설치하여 운영하였다. 학과 설립 10 주년(1998년)을 맞아 40cm 망원경과 6m 돔을 설치하여 교내천문대가 완공되었다. 2000년이 되면서 대중 천문활동 을 위해 이동 천문대를 제작하여 4륜 자동차에 견인하여 여러 지역을 찾아 관측과 강연 활동 등 학과의 대중천문 활동의 특성을 살리는 계기를 만들게 되었다. 학과 설립 20주년(2008년)을 맞으면서 충북 진천에 16개 자동분할 개폐식 스릿의 9m 돔 안에 1m 망원경을 원격관측 시설을 완비하여 대학 본부의 기관으로 충북대학교천문대를 개관하고 관측시설을 완비하였다. 우리의 전통적인 세종시대 천문시설은 당대 최대의 시설이지만 당시 유물들이 모두 소실되어 현존하는 것이 하나도 없음은 실로 아쉬움이 큰 것이었다. 누군가는 그 구조, 형태, 원리, 기능, 사용방법 등을 밝히고 복원을 시도해야 할 시급함이 있었다. 문헌을 통해 1991년부터 학부졸업 논문으로 "고천문 의기(儀器) 복원연구" 분야의 발표를 시작하였다. 그 결과를 통해 세종탄신일에 영릉에서 숭모제 행사 후 그 곳에서 수년간 세종시대 고천문의기 한가지씩 작동모델을 복원하여 제막식을 거행하였다, 유물복원 회사 (주)옛기술과 문화 와 함께 팀을 이루어 매년 제작할 종목을 준비하게 되었다. 간의(簡儀)를 복원한 후에는 일성정시의, 소간의, 앙부일구, 정남일구, 석각천문도, 혼천의, 혼상, 각종 해시계 등 매년 지속적으로 복원되어 큰 규모의 야외 전시장이 완성되었다. 작동모델 설계연구팀의 자문과 제작팀과의 팀웍으로 이룬 성과인 것이다. 한번 시작품이 발표된 모델들은 국내 과학관과 박물관, 천문관에서 후속 모델을 설치하였다. 한국천문연구원과 부산 동래읍성 내에 장영실 과학 동산은 간의와 혼상을 비롯한 각종 해시계들을 설치한 큰 규모의 야외 전시장이다. 조선의 명망 높은 유학자들이 인격적인 하늘을 살펴보았던 혼천의와 일만원권에 그려 있는 국보 230호 자명종 혼천시계(일만원권의 그림)의 작동 모델을 제작하였다. 이와 같은 연구 결과들은 석사과정 박사과정을 통하여 더 심층적인 연구들이 발표되었고, 각종 조선(한국)의 천문의기(天文儀器) 연구 자료들은 연구팀들을 통해 중국과 일본 등 해외에서도 발표되었다. 지금까지 복원된 유물들이 완성되기까지는 참여한 많은 연구원들과 제작팀들이 합심하여 각자의 역할을 수행하여 최종 작동모델들이 하나 둘 완성되는 것이었다. 이것은 참으로 보람된 일이었고, 은퇴 후 지금은 재능기부자로서 즐거운 삶을 이어 갈수 있게 되었다.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.117-125
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• 2019

This study compared the temperature and humidity measured by an aspirated radiation shield (ARS), the accuracy of which has been recently verified, and those measured by a system developed by the parent company (Company A) to investigate and improve the performance of the developed system. The results are as follows. Overall, the two-plate system had a lower radiation shielding effect than the one-plate system but showed better performance results when excluding the effect of strawberry vegetation on the systems. The overall maximum temperature ranges measured by company A's system and the ARS were $20.5{\sim}53.3^{\circ}C$ and $17.8{\sim}44.1^{\circ}C$, respectively. Thus, the maximum temperature measured by company A's system was $2.7{\sim}9.2^{\circ}C$ higher, and the maximum daily temperature difference was approximately $12.2^{\circ}C$. The overall average temperature measured by company A's system and the ARS was $12.4{\sim}38.6^{\circ}C$ and $11.8{\sim}32.7^{\circ}C$, respectively. Thus, the overall average temperature measured by company A's system was $0.6{\sim}5.9^{\circ}C$ higher, and the maximum daily temperature difference was approximately $6.7^{\circ}C$. The overall minimum temperature ranges measured by company A's system and the ARS were $4.2{\sim}28.6^{\circ}C$ and $2.9{\sim}26.4^{\circ}C$, respectively. Thus, the minimum temperature measured by company A's system was $1.3{\sim}2.2^{\circ}C$ higher, and the minimum daily temperature difference was approximately $2.9^{\circ}C$. In addition, the overall relative humidity ranges measured by company A's system and the ARS were 52.9~93.3% and 55.3~96.5%, respectively. Thus, company A's system showed a 2.4~3.2% lower relative humidity range than the ARS. However, there was a day when the relative humidity measured by company A's system was 18.0% lower than that measured by the ARS at maximum. In conclusion, there were differences in the relative humidity measured by the two company's devices, as in the temperature, although the differences were insignificant.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.487-499
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• 2021

Purpose:The purpose of the paper is to review the problems of performance enhancement of safety certification standards and to suggest directions for improvement in order to rationalize safety certification standards for future industrial development and environmental changes. Method: The problems and limitations of the safety certification system are summarized through literature review and interview with manager, and the status of safety certification standards is classified into design standards, performance standards, and detailed standards, and the status analysis is performed. In addition, by synthesizing the results of the investigation and analysis, improvements are suggested to improve the performance of the safety certification standards. Result: Through the survey, the problems and limitations of safety certification could be grouped into six categories: government-led certification system operation, standardized certification standards, long time required to improve certification, poor certification standards preparation system, and lack of reflection of industry opinions. And, as a result of analyzing the certification standards by dividing them into performance and design standards, in the case of machinery, equipment, and protection devices, the design standards were high at 69.7% and 64.9%, whereas in the case of protective equipment, the performance standards were high at 61.1%. In order to improve the performance of safety certification standards centered on design standards, it is necessary to determine the possibility of performance enhancement of the certification standards and determine the feasibility of the inspection test method. In order to improve performance, it was reviewed that it was necessary to establish a systemic foundation and infrastructure, such as strengthening the Product Liability Act, systematizing market monitoring, etc., distributing certification test tasks, and participating in the preparation of certification standards by the private sector. Conclusion: Through this study, the problems and limitations of Korea's safety certification system were summarized and the necessity for performance improvement was reviewed. Performance improvement of safety certification standards is a matter that requires preparatory work, such as legislative revision and infrastructure construction, and requires mid-to-long-term promotion. In addition, rather than improving the overall safety certification standards, the performance requirements for each item subject to certification should be reviewed and promoted, and details should be specified through additional research.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.322-327
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• 2019

This study was conducted to improve the performance of automatic grafting robot using image recognition technique. The stem diameters of tomatoes and cucumber at the time of grafting were $2.5{\pm}0.3mm$ and $2.2{\pm}0.2mm$ for scions and $3.1{\pm}0.7mm$ and $3.6{\pm}0.3mm$ for rootstocks, respectively. The grafting failure was occurred when the different height between scions and rootstocks were over 4 mm and below 2 mm due to the small contact area of both cutting surface. Therefore, it was found that the height difference at the cutting surface of 3 mm is appropriate. This study also found that grafting failure was occurred when the stem diameters of both scions and rootstocks were thin. Therefore, it was suggested to use at least one stem with thicker than the average stem diameter. Field survey on the cutting angle of stems by hand were ranged from 13 to 55 degree for scions and 15 to 67 degree for rootstocks, respectively, which indicates that this could cause the grafting failure problem. However, the automatic grafting robot developed in this study rotates the seedlings 90 degree and then the stems are cut using a cutting blade. The control part of robot use all images taken from grafting process to determine the distance between a center of both ends of stem and a gripper center and then control the rotation angle of a gripper. Overall, this study found that The performance of automatic grafting robot using image recognition technique was superior with the grafting success rates of cucumber and tomato as $96{\pm}3.2%$ and $95{\pm}4%$, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.258-267
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• 2020

The agrivoltaic can produce electricity and grow crops on fields at the same time. It is necessary to analyze the cultivation environment and evaluate the crop productivity under agrivoltaic because the shading point changes according to structure of agrivoltaic and sun's position. Two types of "fixing" and "tracing" agrivoltaic were installed, and a rice cultivation experiment was conducted in the fields under each agrivoltaic and without shading (control). "Hyunpoombyeo" was transplanted on June 7, 2019, and grown with fertilization of 9.0-4.5-5.7 kg/10a (N-P-K). Fifteen weather stations were installed under each agrivoltaic to measure solar radiation and temperature, and yield and yield-related elements were investigated by points. The accumulated solar radiation during the rice growing season in fixing was no much difference between points, and that in tracing was much difference between points. However, the average solar radiations of two agrivoltaics were similar. The mean temperature, yield, and yield-related elements showed a significant difference for the shading rate, and decreased with increasing the shading rate except ripening grain rate and 1000 grain weight of fixing agrivoltaic. In the relationship between shading rate and yield, fixing and tracing were fitted to a logistic equation and a simple linear equation, respectively, and showed a high correlation (tracing: R2 = 0.62, fixing: R2 = 0.73). The shading rate variation by point for two types was large despite similar yield variation. Thus, it needs to be more closely examined the relationship of the shading rate for a specific period rather than the shading rate during the whole growing season.

• Cross-Cultural Studies
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• v.40
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• pp.111-131
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• 2015

An unusual success engendering loyalty among cult fans in the United States, Mamoru Oshii's 1995 cyberpunk anime, Ghost in the Shell (GITS) revolves around a female cyborg assassin named Motoko Kusanagi, a.k.a. "the Major." When the news came out last year that Scarlett Johansson was offered 10 million dollars for the role of the Major in the live action remake of GITS, the frustrated fans accused DreamWorks of "whitewashing" the classic Japanimation and turning it into a PG-13 film. While it would be premature to judge a film yet to be released, it appears timely to revisit the core achievement of Oshii's film untranslatable into the Hollywood formula. That is, unlike ultimately heteronormative and humanist sci-fi films produced in Hollywood, such as the Matrix trilogy or Cloud Atlas, GITS defies a Hollywoodization by evoking much bafflement in relation to its queer, posthuman characters and settings. This essay homes in on Major Kusanagi's body in order to update prior criticism from the perspectives of posthumanism and queer theory. If the Major's voluptuous cyborg body has been read as a liberating or as a commodified feminine body, latest critical work of posthumanism and queer theory causes us to move beyond the moralistic binaries of human/non-human and male/female. This deconstruction of binaries leads to a radical rethinking of "reality" and "identity" in an image-saturated, hypermediated age. Viewed from this perspective, Major Kusanagi's body can be better understood less as a reflection of "real" women than as an embodiment of our anxieties on the loss of self and interiority in the SNS-dominated society. As is warned by many posthumanist and queer critics, queer and posthuman components are too often used to reinforce the human. I argue that the Major's hybrid body is neither a mere amalgam of human and machine nor a superficial postmodern blurring of boundaries. Rather, the compelling combination of individuality, animality, and technology embodied in the Major redefines the human as always, already posthuman. This ethical act of revision-its shifting focus from oppressive humanism to a queer coexistence-evinces the lasting power of GITS.

• Maritime Security
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• v.1 no.1
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• pp.215-240
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• 2020

In 2017, the U.S. DARPA coined 'mosaic warfare' as a new way of warfighting. According to the Timothy Grayson, director of DARPA's Strategic Technologies Office, mosaic warfare is a "system of system" approach to warfghting designed around compatible "tiles" of capabilities, rather than uniquely shaped "puzzle pieces" that must be fitted into a specific slot in a battle plan in order for it to work. Prior to cover mosaic warfare theory and recent development, it deals analyze its background and several premises for better understanding. The U.S. DoD officials might acknowledge the current its forces vulnerability to the China's A2/AD assets. Furthermore, the U.S. seeks to complete military superiority even in other nation's territorial domains including sea and air. Given its rapid combat restoration capability and less manpower casualty, the U.S. would be able to ready to endure war of attrition that requires massive resources. The core concept of mosaic warfare is a "decision centric warfare". To embody this idea, it create adaptability for U.S. forces and complexity or uncertainty for the enemy through the rapid composition and recomposition of a more disag g reg ated U.S. military force using human command and machine control. This allows providing more options to friendly forces and collapse adversary's OODA loop eventually. Adaptable kill web, composable force packages, A.I., and context-centric C3 architecture are crucial elements to implement and carry out mosaic warfare. Recently, CSBA showed an compelling assessment of mosaic warfare simulation. In this wargame, there was a significant differences between traditional and mosaic teams. Mosaic team was able to mount more simultaneous actions, creating additional complexity to adversaries and overwhelming their decision-making with less friendly force's human casualty. It increase the speed of the U.S. force's decision-making, enabling commanders to better employ tempo. Consequently, this article finds out and suggests implications for Korea armed forces. First of all, it needs to examine and develop 'mosaic warfare' in terms of our security circumstance. In response to future warfare, reviewing overall force structure and architecture is required which is able to compose force element regardless domain. In regards to insufficient defense resources and budget, "choice" and "concentration" are also essential. It needs to have eyes on the neighboring countries' development of future war concept carefully.