등산화 아웃솔의 독립적 서스펜션 기능이 발의 안정성 및 부하에 미치는 효과

이기광,최치선,은선덕,Lee, Ki-Kwang,Choi, Chi-Sun,Eun, Seon-Deok 대한인간공학회 2006 大韓人間工學會誌 Vol.25 No.4

To investigate the effects of independent suspension technology(IST) of hiking boot on the stability and load of foot, eight participants performed medial and lateral drop landing from 33.4cm height and 85cm distance to uneven surface while wearing normal & IST hiking boots. For the stability of foot during the drop landing, the balance angle & suspension angle and rearfoot angle was analyzed using high-speed video analysis. Also kinetic analysis using the force plate and insole pressure measurement was conducted to analyze vertical & breaking ground reaction force and pressure distribution. Not only the balance angle & suspension angle but also rearfoot angle was improved with IST boots for lateral drop landing. These results indicate the IST boots may have the suspension function which keeps the foot to be stable during landing. However the IST boots did not show any effect for medial landing. This might be related to the hardness of medial part of outsole. Therefore the softer outsole of medial part could be recommended. Furthermore the impact force & breaking force and insole pressure were reduced with IST boot. These results means that IST boot has not only cushioning effect but also good grip effect. Therefore the hiking boots applied the independent suspension function may help to reduce fatigue and prevent injury such as ankle sprain in hiking on uneven surface.

창문 자동 제어 시스템

이기광(Ki-Kwang Lee),정혁(Hyuck Jung ),김성윤(Sung-Yun Kim),김재명(Jae-Myeong Kim),최선혜(Sun-Hye Choi),반성범(Sung-Bum Pan) 한국정보기술학회 2018 Proceedings of KIIT Conference Vol.2018 No.6

황사예보 및 황사농도에 따른 결막염 질환의 발생 패턴 분석

이기광(Ki-Kwang Lee) 한국경영과학회 2013 經營 科學 Vol.30 No.1

This study has an aim to analyze the effects of ADS on conjunctivitis patients among the residents of Seoul, Korea, between 2005 and 2008. For this purpose, the number of medical services provided to conjunctivitis patients on the days of windblown dust storms and the days without any windblown dust storms were analyzed by conducting paired t-test. The interactive effects of the ADS density and the accuracy of ADS forecast on the fluctuation of conjunctivitis cases were also investigated. The results showed that, even with an accurate forecast issued 24 hours prior to the event, the average number of medical services provided for conjunctivitis was higher on the index days than the comparison days. On the other hand, in cases of failure to provide an accurate forecast 24 hours prior to the ADS event, the number of conjunctivitis attacks reported was statistically significantly higher on the index days for 3~5 days after the occurrence of a dust storm in relation to the comparison days. We also found that the rate of increase in asthma treatments on the index days with low level of PM₁? concentration rather than high PM₁? level was more significant for all lag days. This study provides evidence that ADS events are significantly associated with conjunctivitis symptoms and the failure to forecast ADS events with low PM₁? level might aggravate conjunctivitis disease.

가치스코어 모형을 이용한 기상정보의 기업 의사결정에 미치는 영향 평가

이기광(Ki-Kwang Lee),이중우(Joong-Woo Lee) 한국산업경영시스템학회 2007 한국산업경영시스템학회지 Vol.30 No.2

  In this paper the economic value of weather forecasts is valuated for profit-oriented enterprise decision-making situations. Value is estimated in terms of monetary profits (or benefits) resulted from the forecast user’s decision under the specific payoff structure, which is represented by a profit/loss ratio model combined with a decision function and a value score (VS). The forecast user determines a business-related decision based on the probabilistic forecast, the user’s subjective reliability of the forecasts, and the payoff structure specific to the user’s business environment. The VS curve for a meteorological forecast is specified by a function of the various profit/loss ratios, providing the scaled economic value relative to the value of a perfect forecast. The proposed valuation method based on the profit/loss ratio model and the VS is adapted for hypothetical sets of forecasts and verified for site-specific probability of precipitation forecast of 12 hour and 24 hour-lead time, which is generated from Korea meteorological administration (KMA). The application results show that forecast information with shorter lead time can provide the decision-makers with great benefits and there are ranges of profit/loss ratios in which high subjective reliability of the given forecast is preferred.

태권도 차등점수제 적용 후 체급별 공격 기술 및 득점 유형에 관한 연구

이기광(Ki Kwang Lee),은선덕(Seon Deok Eun) 한국사회체육학회 2004 한국사회체육학회지 Vol.0 No.22

To study on the attack skill and points after applying a graded point system that provide additional point for more aggressive attack in Taekwondo game, 185 games in 14th Busan Asian game were recorded and analyzed. Based on the comparison of the attack skill and points by players` weight, the results and conclusions were as follows; First, most frequently used attack skill in Taekowndo game was Dollyechagi(round kick). Attack frequency in lighter weight players was higher than heavier weight players. Also, after applying a graded point system, it could be supposed that face-attack skills were used more frequently. Second, after applying a graded point system, average points in a game increased. Also there were more points in middle weight players than lighter and heavier weight players. Overall Dollyechagi was most effective attack skill to get point in Taekwondo game. Third, a graded point system might affect to offense style that showed various kicking technique to head rather than trunk. But based on the result that most points in the game were still gain by the round kick, it can be proposed that future study of another differentiated point system will give additional points for not only target but also difficulty of skill.

Public Satisfaction Analysis of Weather Forecast Service by Using Twitter

Ki-Kwang Lee(이기광) 한국산업경영시스템학회 2018 한국산업경영시스템학회지 Vol.41 No.2

This study is intended to investigate that it is possible to analyze the public awareness and satisfaction of the weather forecast service provided by the Korea Meteorological Administration (KMA) through social media data as a way to overcome limitations of the questionnaire-based survey in the previous research. Sentiment analysis and association rule mining were used for Twitter data containing opinions about the weather forecast service. As a result of sentiment analysis, the frequency of negative opinions was very high, about 75%, relative to positive opinions because of the nature of public services. The detailed analysis shows that a large portion of users are dissatisfied with precipitation forecast and that it is needed to analyze the two kinds of error types of the precipitation forecast, namely, ‘False alarm’ and ‘Miss’ in more detail. Therefore, association rule mining was performed on negative tweets for each of these error types. As a result, it was found that a considerable number of complaints occurred when preventive actions were useless because the forecast predicting rain had a ‘False alarm’ error. In addition, this study found that people’s dissatisfaction increased when they experienced inconveniences due to either unpredictable high winds and heavy rains in summer or severe cold in winter, which were missed by weather forecast. This study suggests that the analysis of social media data can provide detailed information about forecast users’ opinion in almost real time, which is impossible through survey or interview.

황사 및 관련예보 정확도가 천식질환 발생빈도에 미치는 상관관계 분석

이기광(Ki-Kwang Lee) 한국산업경영시스템학회 2012 한국산업경영시스템학회지 Vol.35 No.3

황사(Asian dust storm, ADS)란 중국이나 몽골 등 중앙아시아 지역의 사막 지대의 작은 모래나 황토 또는 먼지가 하늘에 떠다니다가 상층풍을 타고 멀리까지 날아가 떨어지는 현상을 말하며, 주로 봄철에 우리나라를 비롯한 동아시아 지역에 영향을 준다. 이와 같은 황사에 영향을 받는 지역에서는 거주민들의 건강에 부정적인 영향을 미치는것으로 알려져 있다. 본 연구는 2005년도에서 2008년도까지 4년간 서울지역 거주민들 사이에서 황사현상이 천식질환에 미치는 영향을 분석하고자 한다. 이를 위해 황사발생일(기준일 또는 index day)과 기준일 대비 7일 전후(비교일 또는 comparison day) 황사가 발생하지 않은 날에 병의원에서 진료를 받은 천식환자 수를 황사예보의 정확도에 따라 비교 분석하였다. 그 결과 24시간 전 제공된 황사예보가 황사발생을 정확히 예측한 경우라 하더라도 비교일 대비 기준일의 천식환자 수가 여전히 더 많다는 사실을 알 수 있었다. 다만, 증가 정도는 통계적으로 유의한 수준은 아니었다는 점에서 정확한 황사예보가 최소한 어느 정도는 천식질환 발생을 저감시키는 효과는 분명히 가지고 있다고 판단할 수 있다. 반면에 24시간 전 황사예보가 황사발생을 정확하게 예측하지 못한 경우에는 비교일 대비 기준 일에서 5~6일 후에 진료 받은 천식환자 수가 통계적으로 유의할 수준까지 높게 나타났다. 하지만, 기준일 및 기준일 다음 날의 경우에는 오히려 천식환자 수가 감소하는 경향을 보였다. 본 연구를 통해 황사예보 및 황사발생의 다양한 경우에 따라 천식환자 수의 일정한 변화패턴이 발견되었으며, 이와 같은 연구결과는 황사 관련 의료서비스 체계를 보다 효율적으로 설계하는데 활용될 수 있을 것으로 기대된다.

스노우보드 부츠의 끈조임 장치가 착용시간, 평형성 및 신발내부압력에 미치는 효과

이기광(Ki-Kwang Lee),이정호(Jung-Ho Lee) 한국생활환경학회 2010 한국생활환경학회지 Vol.17 No.2

To investigate the effect of three different tyoes of snow board boot lace pattern which were traditional(A), dial(B), pulley(C) system, respectively, on the wearing time, the balance abilility, and the in-shoe tibia pressure, various biomechanical tests were performed with ten college recreational snow boarders. Although boot A required longer time to tighten to foot than other boots, that lace type provided better both static and dynamic balance, and tighter fitting between boot and tibia that might be related to greater force transfer from body to snow board. It can be concluded that the original function of lace which provide well-fitting to feet should be more empathized than convenience to design snowboard boot lace system, because snowboard is high injury potential sport.

국내 인터넷 골프 쇼핑몰 활성화를 위한 마케팅 전략

이기광(Ki Kwang Lee) 한국사회체육학회 2001 한국사회체육학회지 Vol.16 No.-

To provide the marketing strategies for internet golf shopping mall in Korea, twenty four golf shopping malls searched on March 30th 2001 by `Yahoo`, the one of famous internet site searching engine, were analyzed intensively. In terms of domain name, 18 sites of 24 sites were using the word of `golf`, and 4 sites were using `.com`. Only 2 shopping malls were dealing with selling the their own companies products and 13 shopping malls had both on-line and off-line shopping mall. Three shopping malls were providing three-dimensional image of goods, while others were provided two-dimensional image of goods. Eighteen shopping malls had good arrangement about goods-information and the diversity of goods. Six shopping malls did not provide on-line order process. Eleven shopping malls did not provide any information for product warranty. In teens of method of payment, seven shopping malls did not provide payment method by credit card. Thirteen shopping malls provided credit card security protocol. For delivering goods to costumer, most shopping malls were connected to parcel company. Although 15 shopping malls had banner advertisement, the number of banner was a few. Ten shopping malls were updating their contents frequently, It was possible to refund and change goods in 20 days in 13 shopping malls. Eighteen shopping malls were using their bulletin board for sharing goods information and exchange market of used goods. Based on above results, several marketing strategies were suggested as follows. First, shopping malls should have their domain names which can be memorized easily and related to word of "golf". Also the name starting with "A" letter has an advantage, because most searching engines shows list alphabetically. Second, number of banner on web site should be increased for profit. Also each shopping mall should provide and/or exchange their banners to other web sites of related companies for advertisement. Third, through the various events which people like to participate, shopping malls should get information of customer which may be used for future marketing. Also, using the well-maintained FAQ and board, shopping malls should provide good service to customer. Fourth, to provide lower price, shopping malls may have their own products or service and use various sales methods, such as mass-sale, auction, etc. Fifth, shopping malls must have a credit card security protocol for customer. It is also possible to apply e-money system for convenience. Futhermore, the warranty of product and safe delivery system should be required. Finally, internet golf shopping malls should make a strategic alliance with huge complex shopping mall which have much better payment delivery system and more customers.

판매지점들의 협조공급을 이용한 재고관리 방법에 관한 연구

이기광(Ki Kwang Lee),윤승철(Seung Chul Yoon) 한국생산관리학회 2016 한국생산관리학회지 Vol.27 No.1

기업들은 여러 지역으로 분산되어 있는 고객들에게 제품을 판매하기 위해 각 지역의 판매를 담당하는 판매지점들을 운영한다. 그리고 판매지점들은 고객 수요를 충족시키기 위해 재고관리 계획에 따라 적정 시점에 적정량을 공급처에 주문하며, 이 주문량은 어느 정도의 제품 조달기간이 경과한 후 도착되어 제품을 판매하게 된다. 이 연구는 재고부족이 발생한 지점의 경우 판매유실 또는 신용상실 등을 막기 위해 재고를 보유하고 있는 지점들로부터 신속한 협조공급을 받아 판매하는 시스템의 재고분석 방법을 제시한다. 분석을 위해 서비스수준 접근방법을 이용하며, 두 가지 서비스수준, 즉 제품에 대한 각 지점의 계획서비스수준과 협조서비스수준의 정의를 사용한다. 이들 두 정의에 의해 목표한 시스템 전체의 서비스수준을 달성하기 위한 안전재고량, 적정 주문점, 지점들 사이의 협조공급량, 그리고 재고관리 비용 등을 분석한다. 이를 위해 먼저 협조공급을 이용하지 않는 각 지점의 독립적인 운영 시스템의 경우 시스템 차원의 목표 서비스수준을 달성하기 위한 각 지점의 안전재고량과 적정 주문점을 분석한다. 이어서 협조공급 시스템 하에서 목표로 하는 시스템 서비스수준을 얻기 위한 각 판매지점의 계획서비스수준을 설정하는 방법을 논의한다. 또한 한 주문주기 동안 품절발생시 타 지점들로부터 받게 되는 협조공급량은 재고관리정책과 협조공급에 따른 비용 등의 문제로 변화될 수 있다. 따라서 다양한 협조공급수준의 변화에 따른 계획서비스수준 설정 방법을 아울러 분석 제시한다. 나아가 이 연구는 제품의 수요변화에 따른 재고분석을 위해 수요예측 시스템을 이용하는 것을 전제로 한다. 따라서 수요예측 시스템에서 제품에 대한 여러 지점들의 월별 수요를 각각 예측하지 않고, 시스템 전체의 월 예측수요로부터 각 지점의 수요발생확률을 이용하여 각 지점의 월 예측수요와 분산을 구하는 효율적인 계산방법을 제시한다. 이와 함께 안전재고와 주문점 결정에 중요한 역할을 하는 제품 조달기간 동안의 예측수요와 분산을 유도하는 과정을 설명한다. In many inventory situations, items for sale are generally stocked at several regional sales branches to meet customer demands in widely spread regions. This research suggests an inventory control method using cooperative sourcing among sales branches when an inventory shortage for an item occurs at one of the sales branches. For the analysis, two different definitions of service levels are used for items: a planned service level and a cooperative service level. Using these two definitions, the research first shows methods to compute the safety stock, order point, and sourcing quantity required to obtain the level of service goal for the entire sales system. Next, we discuss methods to determine the planned service level of each branch in order to achieve the level of service goal under the cooperative sourcing system. Further, we present an effective method to forecast monthly demand and variance for each sales branch using the demand forecast of the entire sales system and each branches probability of demand. Finally, we discuss the topics above and present sensitivity analyses for the various effects of changes in the data for service level, safety stock, order point, sourcing quantity, inventory level, and so on.