• 한국가시화정보학회지
• /
• 제14권2호
• /
• pp.12-17
• /
• 2016

In this work, we investigate the flow velocity controllability of a diffuser-type multiple hydrofoil duct by experimental and numerical flow visualization approaches. The flow velocity controllability is analyzed by changing the angle of the hydrofoil near the outlet, which is the diffuser, while the incoming flow velocity is 0.6 m/s in the experiment. When the diffuser angle is changed from 0 to 7.5 degree, the maximum velocity inside the duct is varied from 1.35 m/s to 1.52 m/s. Also, it is shown from the numerical analysis that the maximum velocity is varied from 1.09 m/s to 1.17 m/s in the same condition. Thus, the aspect of the acceleration in the duct due to the increase of the diffuser angle is similar between the both approaches. Therefore, the multiple hydrofoil duct can be used to control the flow speed inside the duct for continuously extracting power close to a rated capacity.

• Ocean and Polar Research
• /
• 제34권1호
• /
• pp.85-91
• /
• 2012

Physical properties such as sound speed contrast (h) and density contrast (g) of the interested target are key parameters to understand acoustic characteristics by using theoretical scattering models. The density and sound speed of moon jellyfish (common jellyfish, Aurelia aurita s.l.) were measured. Sound speed contrast (h) was measured from travel time difference (time-of-flight method) of an acoustic signal in a water tank for APOP studies (Acoustic Properties Of zooplankton). Density contrast (g) was measured by the displacement volume and wet weight (dual-density method). The sound speed remained almost constant as the moon jellyfish increased in bell length. The mean values${\pm}$standard deviation of h and g were $1.0005{\pm}0.0012$ and $0.9808{\pm}0.0195$), respectively. These results will provide important input for use in theoretical scattering models for estimating the acoustic target strength of jellyfish.

• 경영과학
• /
• 제25권3호
• /
• pp.101-122
• /
• 2008

A wide variety of convergent digital products are emerging through the combination of multiple independent digital technologies. Digital convergence provides new revenue sources for businesses and new ways of satisfying individual needs of consumers. Despite its business and consumer implications, little research has addressed how people perceive or evaluate convergent products. This study aims at understanding how consumers interpret and evaluate convergent digital products by conducting two consecutive studies. Firstly, a survey was conducted to understand how people interpret convergent products in three ways suggested by the conceptual combination theory based in cognitive science. Secondly, an experiment was conducted to investigate the impact of combination strategies and product similarities on user evaluation of convergent products. Study results indicate that similarity of constituent products has a substantial effect on the interpretation of concept combination strategies. Moreover, combination strategy and product similarity were found to have substantial effects on user comprehension, perceived newness, and preferences for convergent products. This paper ends with an examination of the implications and limitations of the study results.

• 지식경영연구
• /
• 제20권4호
• /
• pp.99-118
• /
• 2019

Online financial counseling services are increasingly expanding with the rise of artificial intelligence-based chatbots. It is very important to examine the effects of emoticons noted as alternatives for communicating emotions in online communication between consumers and companies. In this paper, we examine how the use of emoticons affects the consumer's response and investigate the moderating roles of type of counseling agents (human vs. chatbot) and the consumer's subjective financial knowledge. The results show that the use of emoticon in the conversation brings a positive effect on the consumer's intention to use of online chat counseling service. When participants had relatively low subjective financial knowledge, they had higher intention to use online chat counseling services with emoticons only when the agent type was chatbot. When the type of counseling agent was human, this positive effect of the emoticon did not occur. On the other hand, when participants had relatively high subjective financial knowledge, they had higher intention to use online chat counseling service with emoticons only when the agent type was human. This study contributes to providing practical implications to build online chat counseling service using chatbot in the financial industry by studying users' intention depending on the type of agents and the level of their subjective knowledge.

• 복식문화연구
• /
• 제11권5호
• /
• pp.697-710
• /
• 2003

The Purpose of this study was to prospect new costume culture of 21st Century and to understand the meaning of clothing and clothing behavior which represent on Korean Seasonal Costumes expressed in novel, Honpul. The results were as follows; There are special Costumes in a Year. They are New year, First full moon, Servants day, making seasonings, Doo Rae, Wha-cheon Nori(enjoying blossoms) Costumes during spring season, Dan-Oh Costume in summer and Ya-Kwang-Gui(keeping shoes at all night), Su-Ya(overnight), Yeam-Bal(burning dropped hairs) Costume in winter season. There were many relationship with clothing in new year, Wha-cheon Nori and Servants day Costumes, but they only had adorning meaning without special symbolic or incantational meaning. Clothing and clothing behaviors in Seasoning making day Costume, Dan-Ho costume and Ya-Kwang-Gui, Su-Ya, Yeam-Bal Costumes contained practical meaning with incantational meaning. There were Servants day costumes and Doo-Rae Costumes for lower classes, New year and Wha-cheon Nori costumes for the higher classes. But the First full moon day costume was for both classes. This study will make us to grasp the meaning of clothing culture with Korean Seasonal Costumes, and be useful to measure the changes of Korean costume cultures.

• 정보처리학회논문지D
• /
• 제17D권1호
• /
• pp.53-58
• /
• 2010

본 연구의 목적은 스마트폰 상에서 이용 가능한 실용적인 위치 기반 서비스로 개인 맞춤형 소극장 안내 시스템을 개발하는 것이다. 본 연구에서는 이를 위해 GPS 수신기를 내장한 스마트폰에서 이용 가능한 대학로 소극장 안내 시스템을 설계 구현하였다. 이 시스템은 GPS를 이용하여 사용자의 현재 위치를 자동으로 파악하고 이를 지도에 맵핑하여 표시한다. 또한 파악된 사용자의 현재 위치를 중심으로 가까운 극장 및 공연에 대한 개인 맞춤형 정보를 효과적으로 제공하도록 설계 구현하였다. 구현된 시스템은 현장 실험을 통한 보정 작업을 통하여 실제 상황에서 효과적으로 이용 가능하도록 최적화하였다.

• 한국수소및신에너지학회논문집
• /
• 제30권2호
• /
• pp.119-127
• /
• 2019

Reliable $H_2$ supply is necessary for entering a $H_2$ society. Among the various $H_2$ storage and transportation methods, liquid organic $H_2$ carrier (LOHC) is in the spotlight because of a lot of advantages compared to conventional one such as compressed $H_2$ and liquefied $H_2$. Therefore, we performed preliminary economic analysis of $H_2$ supply cost using LOHC for a $H_2$ production capacity of $300Nm^3\;h^{-1}$ employing itemized cost estimation and sensitivity analysis to evaluate economic viability of this technology in Korea.

• Ocean and Polar Research
• /
• 제35권3호
• /
• pp.205-217
• /
• 2013

We investigated the population dynamics of Aurelia aurita in Sihwa Lake from April to October in 2009. Salinity ranged from 5.9 to 30.7 psu at the surface. Abundance of mesozooplankton ranged from 3 to 111,874 indiv. $m^{-3}$. Ephyrae occurred from April to May with the peak in abundance occurring on 17 April. Maximum density of ephyrae was observed near the power transmission towers that are known to be habitats of polyps. Mortality of ephyrae was lower than in other areas because of the abundant prey concentration and the absence of predators. Young medusae occurred from April to July with the peak in abundance occurring on 8 May. Adult medusae occurred from May to July with the peak in abundance on 25 June and they disappeared before the rainy season. Planula occurred only in May and June with the peak in abundance on 25 June. Growth rates of Aurelia aurita ranged from -0.06 to 0.34 $d^{-1}$, and decreased rapidly after May. The period in which adult medusa occurred was restricted, compared with those in other area in Korea (e.g., Masan Bay) and Japan (e.g., Tokyo Bay). In the period of this study, the available food was limited in June and salinity decreased to ca. 20 psu in May because of the beginning of the wet season. We assumed that the exceptionally short period of occurrence of the medusa may be a response of adults to changes in temperature, salinity or food limitation which leads to the precocious maturation of young medusa and the release of planula and that the brief occurrence of medusa was caused by an abrupt decrease in activity after the release of planula.

• 멤브레인
• /
• 제17권3호
• /
• pp.191-196
• /
• 2007

본 연구에서는 경도 이온의 화학적 침전을 위하여 지하수에 과량의 Lime-Soda ash를 주입하여 플럭(floc)을 형성한 다음 침전과정을 십자흐름(Crossflow) 방식의 관형 세라믹 분리막을 이용한 한외여과(UF) 공정으로 대체하였다. 그 결과 두유 포장팩 세척수로 사용하고 있는 지하수의 총경도를 10 mg/L as $CaCO_3$ 이하로 감소시킬 수 있었다. 한편, TMP(Trans-membrane pressure) 및 유량 변화 실험에서 투과선속(Permeate flux, J) 및 무차원한 투과선속($J/J_0$) 변화를 조사하여, TMP 및 유량이 무기물로 형성된 응집 플럭에 의한 막오염에 미치는 영향을 알아보았다. 그 결과, 본 실험 범위에서 TMP 및 유량 변화가 막오염과 총경도 제거율에 미치는 영향은 거의 없었다.

• 대한기계학회논문집A
• /
• 제38권9호
• /
• pp.933-941
• /
• 2014

본 논문에서는 대표적 투영기반 모델차수축소법인 크리로프 부공간 모델차수축소법(KSM)과 모드중첩법(MTM)을 고려하여 주파수응답해석에 대한 수치적 정확도와 효율성을 비교하였다. 두 모델차수축소법의 수치 정확도 비교를 위하여 주파수응답해석 결과, 축소차수 및 관심주파수에 따른 상대오차를 고려하였으며 이후에 오차수렴지표를 통한 자동적인 축소차수의 결정이 가능 여부를 확인하였다. 효율성 비교를 위해서는 각 축소모델의 주파수응답 해석시간 및 축소차수에 따른 변환행렬 생성시간을 비교하였다. 자동차 현가장치에 대한 유한요소모델을 적용예제로 선정하여 수치 비교를 수행하였다.