• Environmental Engineering Research
• /
• 제19권1호
• /
• pp.75-81
• /
• 2014

Methanotrophic denitrification under a non-aerated condition (without external supply of oxygen or air) was investigated in a bioreactor coupled with a membrane diffuser. Batch experiment demonstrated that both methane consumption and nitrogen production rates were not high in the absence of oxygen, but most of the nitrate was reduced into $N_2$ with 88% recovery efficiency. The methane utilized for nitrate reduction was determined at 1.63 mmol $CH_4$/mmol $NO_3{^-}$-N, which was 2.6 times higher than the theoretical value. In spite of no oxygen supply, methanotrophic denitrification was well performed in the bioreactor, due to enhanced mass transfer of the methane by the membrane diffuser and utilization of oxygen remaining in the influent. The denitrification efficiency and specific denitrification rate were 47% and 1.69 mg $NO_3{^-}-N/g\;VSS{\cdot}hr$, respectively, which were slightly lower than for methanotrophic denitrification under an aerobic condition. The average concentration of total organic carbon in the effluent was as low as 2.45 mg/L, which indicates that it can be applicable as a post-denitrification method for the reclamation of secondary wastewater effluent. The dominant fatty acid methyl ester of mixed culture in the bioreactor was $C_{16:1{\omega}7c}$ and $C_{18:1{\omega}7c}$, which was predominantly found in type I and II methanotrophs, respectively. This study presents the potential of methanotrophic denitrification without externally excess oxygen supply as a post-denitrification option for various water treatment or reclamation.

• 유통과학연구
• /
• 제16권4호
• /
• pp.67-74
• /
• 2018

Purpose - Most of the amendments to the law on the improvement of the distribution structure of mobile communication terminal equipment, the fully self-sufficient system of terminals, and the separated disclosure system on the terminals are aimed at securing transparency of the distribution structure by eliminating or reducing handset subsidies. This study investigates what items are important for the purchase of mobile phones in various and rapidly changing mobile phone markets from the consumer's point of view and tries to make a strategic suggestion for future mobile distribution strategies. Research design, data, and methodology - The procedure of this study takes place in four steps. In step 1, only the SF type respondents selected for this study were extracted through MBTI analysis. In step 2, they were divided into three hierarchies for the AHP analysis and each element was arranged. In step 3, the AHP analysis was converted to a Fuzzy-AHP number using the trigonometric centroid method. This was to eliminate the ambiguity of the response by converting into a fuzzy number even if data consistency was maintained with CI value below 0.1. In step 4, the number of converted 2-layer and 3-layer was combined to derive the priority when the final handset is selected. Results - First, the highest importance among the four items in the second tier was the terminal function item, followed by brand, price, and design item. Second, in the third tier, the highest importance was level of after-sales service, followed by device price, processing speed, ease of use, usefulness, and rate system. Third, the arithmetic average of the determinant of the fuzzy function showed that processing speed, ease of use and usefulness in the function item, level of after-sales service in the brand item, and device price in the price item were the five most important factors among 16 choice factors. Conclusions - First, there will be a change in the consumption patterns of consumers who have compared distributors and dealers to purchase handsets with more subsidies. Second, it is highly likely that people will purchase new handsets only when they need to change their devices because they can not receive subsidies by switching phone brands any more.

• Journal of the Korean Wood Science and Technology
• /
• 제22권1호
• /
• pp.20-27
• /
• 1994

Water repellent preservative (WRP) treated and untreated, small-sized specimens prepared from semiwater resistant, water resistant, and tegofilm-overlaid plywood were exposed to outdoor weathering for one year. Exterior durability of specimens was evaluated on the basis of changes in dynamic modulus of elasticity, degree of delamination, modulus of elasticity, modulus of rupture, and glueline shear strength. Among untreated specimens, tegofilm-overlaid plywood showed the best outdoor durability, and durability between semiwater resistant and water resistant plywood was similar. Although WRP treatment increased the durability of all types of plywoods, the effect of treatment on the increase in durability for semi water resistant plywood was not distinct. Accordingly, it can be concluded that semi water resistant plywood, which is used for temporary construction such as concrete formwork in our country, can not be inadequate for exterior use, regardless of WRP treatment. The bending strength and glueline shear strength of untreated water resistant plywood measured after weathering for one year did not exceed the minimum value specified by Korean Standard (KS), thereby the outdoor use of water resistant plywood was not desirable without WRP treatment. Exterior durability between treated water resistant plywood and untreated tegofilm-overlaid plywood was very similar. This result suggests that if an exposed plywood surface is treated with WRP regularly water resistant plywood can be used for temporary construction. This suggestion, however, needs to be investigated. In summary, semiwater resistant plywood cannot be used for temporay construction regardless of WRP treatment. Water resistant plywood can be used only with WRP treatment. Comparing the cost of tegofilm-overlaid plywood to costs of water resistant plywood and WRP treatment, however, it can be concluded that use of tegofilm-overlaid plywood for temporay constrution is strongly suggested from the point of view of both outdoor durability and costs.

• 디지털융복합연구
• /
• 제18권11호
• /
• pp.99-109
• /
• 2020

유료 멤버십은 지속적 거래를 통해 장기 고객을 확보할 수 있는 유용한 마케팅 방법이다. 본 연구는 국내 쇼핑 플랫폼 기업들이 신규로 유료 멤버십을 출시하거나, 운영중인 멤버십을 개선하고자 할 때 참고할 수 있도록, 해외의 대표적 멤버십인 Amazon Prime, Alibaba 88 멤버십, Rakuten Super Point를 벤치마킹하였다. 3가지 멤버십 서비스의 공통점은 경제적 이익, 편리한 경험, 차별적 대우 제공이었으며, 이커머스를 넘어서 소비 생활 전반을 장악한 거대 서비스 기업이 되었다는 점이 특징이었다. 국내 기업은 3가지 공통점 외에 소비자에게 전달하고자 하는 핵심 고객 가치를 정하고 장기적 관점에서 유료 멤버십이 운영될 수 있도록 혜택을 구성해야 할 것이다. 본 연구는 실무적 관점의 기여도가 높은 연구로, 추후 유료 멤버십 전문가 대상의 실증분석 및 고객 사용자 조사가 필요하다.

• 천문학논총
• /
• 제30권1호
• /
• pp.1-9
• /
• 2015

The National Foundation Day of Korea (개천절, 開天節) is currently celebrated on October 3 in Gregorian calendar. We review the history of dating the National Foundation Day of Korea and make a suggestion that it be celebrated on October 3 in the lunar calendar. We present numerous historical records on heaven-worship rites supporting the date October 3 in the lunar calendar. It is pointed out that October 3 in the solar calendar has been adopted in 1949 by the National Assembly with the thought that the lunar calendar is inferior and behind the times. The thought originates from misunderstanding on the value of the lunar calendar and from the ignorance of importance of history and tradition. Since there are now many national holidays that follow the lunar calendar, the logic of the National Assembly in 1949 also makes no sense. We emphasize that the lunar calendar should be followed for the National Foundation Day of Korea for its historical and symbolic characteristics restoration. We also investigate the year of the foundation of the first country of Korea, Dangun Joseon. It is found that even though the majority of the literature before late 15th century recorded the beginning year of Dangun Joseon dynasty to be equal to that of Liao Dynasty (堯), it was accidentally changed to the 25th year of Liao Dynasty in 1484 through a misinterpretation of the previous records. We claim that the beginning year of Dangun Joseon should be set to that of Liao Dynasty as recorded in the original literature in the earlier days. According to the two main opinions accepted by Korea, the beginning year of Liao Dynasty was 2357 B.C. or 2333 B.C., which correspond to the year of Gap-Jin (the 41st year of the sexagenary cycle) or Mu-Jin (the 4th year of the sexagenary cycle), respectively.

• 한국임상약학회지
• /
• 제20권3호
• /
• pp.183-192
• /
• 2010

While Self-monitoring of blood glucose (SMBG) has been recommended in some diabetes mellitus (DM) patients population according to the 2010 American Diabetes Association (ADA), 2007 Korean Diabetes Association (KDA), 2005 International Diabetes Federation guideline, it is excluded from a routine insurance coverage for outpatients in Korea. The objective of this study is to meta-analyze the impact of SMBG on HbA1c in non insulin-treated diabetes mellitus (NIT) DM patients. Published clinical literatures were identified through electronic database searches from inception and until May 2010. Studies were selected if they met the following inclusion criteria: 1) randomized controlled trials (RCTs), 2) comparing SMBG with non-SMBG in NIT type 2 diabetes, 3) measuring HbA1c as an outcome. Literature qualities were assessed by the Scottish Intercollegiate Guidelines Network Checklist. The mean difference of HbA1c between the 2 groups was pooled from non-heterogeneous 6 RCTs by meta-analysis using Review Manger (RevMan) Version 5.0 program. Pooled results demonstrated that SMBG is associated with a statistically significant improvement in glycemic control (mean HbA1c difference -0.23, 95%CI -0.32, -0.13). Sensitivity analysis showed that glycemic controls were significantly improved in patients with shorter study duration, more frequent self-monitoring, higher baseline HbA1c value, and without prior SMBG experiences. Conclusively SMBG is effective in improving glycemic control in NIT DM patients, but additional evidences from further researches in Korean patients and cost-effectiveness analysis would be necessary to make a suggestion for coverage expansion.

• 한국게임학회 논문지
• /
• 제2권2호
• /
• pp.66-71
• /
• 2002

한민족의 공통적인 삶의 풍속은 신분이나 계급의 구분 없이 삶의 감정을 반영하고 있다. 우리 민족만이 가지는 정서와 해학과 유머가 곁들여진 멋들어진 그림으로서의 풍속화는 우리의 역사와 함께 하며, 진실을 담아내는 그릇처럼 사실성과 기록적 성격, 도상적인 전통미를 드러내고 있다. 각각의 시대상황과 문화, 예술, 철학, 종교 등을 화면의 조화로움과 미의 세계를 구축하며 그려진 풍속화야말로 게임그래픽의 도상학적 원류로 보아도 좋을 것이다. 게임이 가상현실의 재현으로, 그 속에서 게임을 즐기는 유저들이 생활하는 또 하나의 공간으로 이해 됐을 때, 창조적인 기획력과 예술성 있는 그래픽의 개발은 반드시 필요하며, 또한 새로운 컨텐츠의 개발로서, 우리의 전통 풍속화에 대한 관심이 필요한 때이다. 풍속화에 대한 현대적인 재해석과 표현기법의 개발로, 게임그래픽 도상의 다변화를 꾀해 다양한 연령층의 유저 확보가 가능해진다면, 게임의 저변화로 게임산업 발달의 초석을 이룰 것은 자명한 일이다.

• 한국정보시스템학회지:정보시스템연구
• /
• 제25권2호
• /
• pp.153-171
• /
• 2016

Purpose This study suggests the development of forecasting model for local cable TV advertisement. In order to verify the expected effect of the suggestion, using the causal loop map of System Dynamics, the factors affecting the prospects of cable TV commercial market were divided into 5 groups. Then targeting 97 people involved in the cable TV commercial market in Busan, Ulsan, and Gyeongnam, a survey was conducted on their perception of the current status of local advertisement market and future prospect. Design/methodology/approach The analysis of the collected data shows that workers in advertising and advertisers perceive the influence of cable TV as an advertising media to be high, while clearly understanding the problems of cable TV commercial market. Based on this the effects on the prospects of cable TV commercial market were analyzed and a forecasting method called Weighted Moving Average was applied. In order to improve accuracy of the added value of Weighted Moving Average, the 5 factors were divided into qualitative factors and quantitative factors, and using Multi-attribute Decision Making method, all the factors were normalized and weighting factors were deduced. The result of simulating the prospects of cable TV commercial market using Weighted Moving Average, both qualitative and quantitative factors showed downward turn in the market prospect for the following 10 years. Findings The result reflects generally negative perception of advertisement viewers about the prospects of cable TV commercial market. Compared to the previous studies on domestic cable TV commercials that focused on policy suggestions and surveys on perception of current status, this study has its significance in that it used scientific method and simulation for verification.

• 융합보안논문지
• /
• 제16권7호
• /
• pp.13-19
• /
• 2016

최근 국내를 대표하는 중요 키워드 중 하나가 O2O(온 오프라인 연계)이다. O2O(온 오프라인 연계) 시장은 온라인 상거래와 오프라인 상거래가 겹쳐지는 교집합 영역이라고 할 수 있다. 스마트폰의 보급 및 대중화는 결제시장 환경을 기존 PC 기반의 온라인 중심에서 모바일 중심(핸드폰)으로 이동하면서 서비스 영역이 온 오프라인 시장까지 확대되고 있다. 이러한 모바일로의 중심 이동은 데이터 보안이 온라인 중심 결제환경에 비해 취약하나 편리성으로 인하여 모바일 중심의 결제서비스가 우선시되는 경향을 보임으로써 보안의 위협이 더욱 증가하고 있다. O2O(온 오프라인 연계) 서비스 확대는 현재 초기 단계로써 그 파급의 범위가 일부에 국한된 변화로써, 온라인 거래, 오프라인 거래라는 기존의 굳건하게 구축된 VAN과 PG 각각의 영역에서 균열을 줄 수 있는 상황이며, 향후 큰 요인으로 작용할지 몰라도 지금까지는 상호간의 경계의 붕괴를 이끌어 낼 만큼의 동기부여는 되지는 못하고 있다. 이에 본 연구에서는 그동안 결제 시장에서 관습적으로 적용되어 오던 스마트폰을 활용한 모바일 결제서비스는 비대면을 거래 방식인 PG를 활용하여 결제되어야 한다는 방식에 대해서 실증적 연구를 통하여 NonPG 방식을 통해서 그 가능성을 제시 하고자 한다.

• 대한조선학회논문집
• /
• 제52권5호
• /
• pp.395-406
• /
• 2015

The Ballast Water Treatment System was developed to prevent the unintended transport of unwanted organisms from one region to another as demanded by the IMO (International Maritime Organization). Although various types of BWTS in the world have been developed until now and applied to various ships, there has been no systematic basis for its selection and installation. Currently, the system selection and installation are as per ship owner’s suggestion or by easy installation point of view by the shipyard. In order to organize, systemize and solve problems related to the selection and installation of BWTS, a definitive study has been performed to come up with the best alternative to derive value and criteria which were to be met for vessels which are to be equipped with BWTS. Multiple criteria were compared alongside each other during the course of this study. Accordingly an AHP (Analytic Hierarchy Process) analysis method for A, B and C companies were done for container ships with size 10,000 TEU and above. Equipment type for “A” company is “Filter, UV & TiO2” combined type. For “B” company it is “Filter & UV” combined type. Finally for “C” company it is “Electrolysis” type. Henceforth, the results of this study aims to come up with the optimum way to select the best and the most suitable BWTS for a certain vessel.