카메룬은 인구증가와 도시화가 진전됨에 따라 쌀을 수입에 의존하고 있는 국가이다. 농업이 시장중심으로 전환되면서 소비자들의 선호 역시 달라지고 있다. 본 연구에서는 카메룬 북서부의 Mezam과 Ngo-ketunjia 지역 소비자의 쌀 선호도에 영향을 미치는 요인을 조사하였다. 특히 카메룬에서 소비자 선호에 영향을 주는 요인들에 대해 Mezam와 Ngoketunjia Divisions of the North West Regions 라는 사례연구와 함께 살펴보았으며 구조화된 설문지를 통해 주요 시장 지역들에 걸쳐 300명의 쌀 소비자들을 대상으로 조사하였다. 사회 경제적 요소들, 유도된 소비자 행동이나 선호를 확인하기 위해서 다항식 기호 논리학 회귀 분석을 사용하였고 소비자 선택에 영향을 미치는 쌀의 품질이나 시장 속성을 확인하기 위해 선형회귀분석을 사용하였다. 조사 분석 결과 소비자들은 오직 지역 쌀만 먹는 부류, 오직 수입된 쌀만 먹는 부류, 지역 쌀과 수입쌀을 모두 먹는 부류의 3가지 구매 형태를 나타냈다. 쌀 선호도에 영향을 미치는 주요 사회경제적 요소로는 소비자의 소득, 교육, 직업 수준인 것으로 나타났다. 소비자의 쌀 선호에 영향을 미치는 품질 요소는 맛, 향, 질감, 도정 후 낟알 색의 흰 정도였고, 시장 속성에 관해 소비자의 쌀 선호에 영향을 미치는 요소는 쌀의 출처와 구입 가능성이었다. 이러한 요소들을 2가지 차원으로 나누어 볼 때, 생산성과 쌀 품질에 관한 차원은 카메룬의 쌀 소비에 있어서 중요한 영향을 미친다고 확인 할 수 있었다.

본 연구는 비시장평가법인 조건부가치평가법을 통해 수질개선을 위한 지불용의액을 추정 하였다. 연구 지역은 심각한 수질오염으로 직·간접적인 피해를 입고 있는 베트남의 하노이 To Lich 강 유역이며, To Lich 강 주변의 거주민들을 대상으로 설문조사를 실시하였다. 이중양분선택형 질문을 통해 설문 내용을 디자인하였고, 설문조사를 통해 얻어진 표본으로 이변 량프로빗모형을 사용하였다. 그 결과, 베트남 하노이지역의 거주민이 수질개선을 위하여 연간 지불용의액은 약 VND 202,560원으로 나타났다. 또한 지불용의액에 영향을 주는 중요한 변수는 사회경제적 변수로 나이, 소득으로 나타났고, 거주민의 건강에 대한 관심도 통계적으로 유의한 변수로 나타났다. 본 연구는 하노이의 To Lich 강에 조사 지역을 한정하여 진행하였기 때문에, 연구 지역 범위를 확대시켜 향후 연구가 진행 되어야 할 것이다. 본 연구의 결과는 지속 가능한 수질 관리의 중요성을 강조하며, 추후 베트남 수질 개선 정책에 환경적 편익 정보를 제공하는데 도움을 줄 것으로 기대된다.

The study had subject to find out what factors Korean automobile consumer is considering in their decision to purchase cars in the situation of the growing competition in the domestic automobile market. In order to this end, the previous study was reviewed to select various factors considered in the process of buying cars. Based on this, Analytic Hierarchy Process was used to prioritize which factors were considered more important by consumers. In the result of study, we could find that performance had the highest priority, and the second ranking was the price. In contrast, image of brand and convenience of maintenance were shown to be relatively low in importance, ranking 3rd and 4th, respectively. Beside, we could recognized the ranking of other detailed factors. This study has an academic implication in that it is able to grasp the latest tendency of consumers’ purchase choice of car and to make conclusion by applying AHP analysis method to study of related subject. It also have practical significance that can be a basis for make sense what factors should be taken by the automobile industry to uprise the purchase of the consumers through the identification and preparation of the purchase selection criteria of domestic automobile buyers.

Salicylic acid (SA) is an essential plant growth regulator that functions as a signaling molecule in plants. The purpose of this study was to clarify how the exogenous application of SA counteracts aluminum stress-induced growth and biomass yield reduction in alfalfa exposed to aluminum (Al) stress. Two-week-old alfalfa seedlings were exposed to a combination of AlCl3 (0 μM, 50 μM and 100 μM, respectively) and SA (0.1 mM) for 72 hours. We observed, Al stress-induced plant growth inhibition and forage yield reduction are Al stress-dependent manner. A significant reduction of plant height (42.0-52.9%), leaf relative water content (13.0-21.4%), root length (35.4-48.7%), shoot fresh weight (31.2-25.9%), root fresh weight (15.4-23.3%), shoot dry weight (12.7-22.2%), roots dry weight (47.3 -53.5%), were observed in alfalfa. In contrast, SA alleviated the Al-stress and enhanced growth and biomass yield in alfalfa. This study provides useful information concerning the role of SA that counteracts aluminum stress-induced growth and yield reduction in alfalfa.

Most demand forecasting studies for telecommunication services have focused on estimating market size at the introductory stage of new products or services, or on suggesting improvement methods of forecasting models. Although such studies forecast business growth and market sizes through demand forecasting for new technologies and overall demands in markets, they have not suggested more specific information like relative market share, customers’ preferences on technologies or service, and potential sales power. This study focuses on the telecommunication service industry and explores ways to calculate the relative market shares between competitors, considering competitive situations at the introductory stage of a new mobile telecommunication service provider. To reflect the competitive characteristics of the telecommunication markets, suggested is an extended conjoint analysis using service coverage and service switching rates as modification variables. This study is considered to be able to provide strategic implications to businesses offering existing service and ones planning to launch new services. The result of analysis shows that the new service provider has the greatest market share at the competitive situation where the new service covers the whole country, offers about 50% of existing service price, and allows all cellphones except a few while the existing service carrier maintains its price and service and has no response to the new service introduction. This means that the market share of the new service provider soars when it is highly competitive with fast network speed and low price.

인공지능은 다양한 분야에서 사람을 대신하여 성과를 보여준다. 게임 분야에서도 인공지능은 다양한 방면으로 사용된다. NPC(Non Player Character) 제작, 게임 난이도, 콘텐츠 생성 등의 분야에서 활용되고 있다. 그러나 게임에서 사용되는 인공지능은 우수한 성과를 보여주며 사람을 이기기 위해 연구된다. 우수한 인공지능 모델이 게임에 존재하여 게임의 난이도가 상승하게 되면 플레이어가 게임에 흥미를 잃는 경우도 있다. 따라서 본 논문의 목적은 사람과의 대결이 아닌 사람을 서포트 하는 인공지능의 개발이다. 현재 모바일 시장의 게임에는 자동 사냥 시스템이 존재한다. 게임에서 이 시스템은 난수 방식을 사용하기 때문에 효율이 떨어진다. 그러므로 본 논문에서는 병렬구조의 DNN 모델을 사용하여 효율적인 자동 사냥 시스템을 구축한다. 새로 구축한 모델과 기존에 사용하던 난수 방식의 모델을 게임을 통해 비교한다.

Most of the data envelopment analysis (DEA) models evaluate the relative efficiency of a decision making unit (DMU) based on the assumption that inputs in a specific period are consumed to produce the output in the same period of time. However, there may be some time lag between the consumption of input resources and the production of outputs. A few models to handle the concept of the time lag effect have been proposed. This paper suggests a new multi-period input DEA model considering the consistent time lag effects. Consistency of time lag effect means that the time delay for the same input factor or output factor are consistent throughout the periods. It is more realistic than the time lag effect for the same output or input factor can vary over the periods. The suggested model is an output-oriented model in order to adopt the consistent time lag effect. We analyze the results of the suggested model and the existing multi period input model with a sample data set from a long-term national research and development program in Korea. We show that the suggested model may have the better discrimination power than existing model while the ranking of DMUs is not different by two nonparametric tests.

In the summer season, natural ventilation is commonly used to reduce the inside air temperature of greenhouse when it rises above the optimal level. The greenhouse shape, vent design, and position play a critical role in the effectiveness of natural ventilation. In this study, computational fluid dynamics (CFD) was employed to investigate the effect of different roof vent designs along with side vents on the buoyancy-driven natural ventilation. The boussinesq hypothesis was used to simulate the buoyancy effect to the whole computational domain. RNG K-epsilon turbulence model was utilized, and a discrete originates (DO) radiation model was used with solar ray tracing to simulate the effect of solar radiation. The CFD model was validated using the experimentally obtained greenhouse internal temperature, and the experimental and computed results agreed well. Furthermore, this model was adopted to compare the internal greenhouse air temperature and ventilation rate for seven different roof vent designs. The results revealed that the inside-to-outside air temperature differences of the greenhouse varied from 3.2 to 9.6oC depending on the different studied roof vent types. Moreover, the ventilation rate was within the range from 0.33 to 0.49 min-1. Our findings show that the conical type roof ventilation has minimum inside-to-outside air temperature difference of 3.2oC and a maximum ventilation rate of 0.49 min-1.