• Fire Science and Engineering
• /
• v.33 no.4
• /
• pp.83-88
• /
• 2019

This study examined the concentration of combustion gases while considering low ventilation and respiration frequency. A one-quarter-size ISO 9705 room corner test was performed. The concentrations of carbon monoxide and oxygen were measured in each case with the continuous inhalation of combustion gas with low ventilation (2, 6, and 10 LPM) and different respiration frequencies (2 s, 5 s, and infinity). The combustion of a gasoline pool fire in the compartment had a theoretical heat release rate of 5.34 kW. The results show that the deviation of the gas concentrations becomes higher as the low ventilation increases compared to the respiration frequency. In addition, as the respiration frequency increases, the variation in the minimum oxygen concentration is larger than the average value, while in the case of carbon monoxide, the variation in the average value is larger than the maximum value. These results show that the inhalation characteristics of refugees should be considered to investigate fires.

• Korean Journal of Environment and Ecology
• /
• v.29 no.6
• /
• pp.947-951
• /
• 2015

This study presents proper irrigation interval for the soil condition of green roof system and the smooth growth of the landscaping herbaceous plants available and reveal the need for irrigation in rooftop conditions. Twenty kinds of greenery plants are tested on ground paved wood panels where rain and wind shielder is installed. Before test, irrigation is conducted fully to experimental plants and then soil moisture in pot is measured after every ten minutes. In conclusion, it is suggested that the irrigation has to be carried out every 4~5 days in order to minimize water and heat stress of plants. Also, irrigation management is an essential prerequisite for good condition and the smooth growth of plants and environmental effects in green roof system.

• 한국HCI학회:학술대회논문집
• /
• 2006.02b
• /
• pp.810-814
• /
• 2006

그 동안 개발된 시뮬레이터들은 주로 단안 정보에 기초한 것들이 대부분이었고, 양안 정보를 제공하더라도 사용자의 움직임을 반영하지 못하였다. 양안정보를 제공하지 못하는 시뮬레이터는 게임으로써는 재미에 한계가 있고, 훈련 도구로써 실제 수행에 도움을 주기 어렵다. 본 연구는 사용자의 움직임을 고려한 양안 정보를 제공하는 외야수 뜬 공 잡기 가상 현실 시뮬레이터를 개발하여 이러한 문제점들을 해결할 수 있는 토대를 마련하였다. 그리고 양안 정보 제공의 중요성과 개발된 시뮬레이터의 타당성 및 유용성을 검증하기 위해 본 시뮬레이터를 이용하여 공의 위치 판단 과제를 실시하였다. 양안 시차가 주어진 조건과 주어지지 않은 조건 각각에 두 집단 구성원들을 무선적으로 배치하여 정답률과 반응 시간을 측정하였다. 숙련자들은 양안시차가 주어진 조건에서 더 좋은 수행을 보인 반면, 일반인들은 양안시차가 주어지지 않은 조건에서 더 좋은 수행을 보였다. 이는 뜬 공 잡기 상황에서 양안정보가 숙련자들에게는 유용하지만 비숙련자들에게는 그렇지 않았음을 보여준다. 또한 숙련자들이 정답률과 반응 시간 모두에서 일반인들보다 더 좋은 수행을 보였고 이는 통계적으로 유의미하였다. 이와 같은 가상 현실 시뮬레이터는 양안 정보를 제공함으로써 이전의 시뮬레이터들보다 게임이나 훈련 도구로 사용함에 있어 더 효과적이다. 또한 인간의 운동 수행에 관련된 연구를 하는데 유용하게 사용될 수 있다.

• Korean Journal of Logic
• /
• v.13 no.1
• /
• pp.101-128
• /
• 2010

In this paper I explore the theory of agent causation proposed by T. O'Connor. According to the theory, we can't explain an agent's control over his intention and action without appealing to 'agent causes events'(shortly, ACEs). But I argue that ACEs can't be a help to an agent's control over his intention and action. For this I show that reason-responsiveness is a necessary condition for an agent's control. In order for ACEs to help in explaining an agent's control, ACEs must be able to satisfy 'reason-responsiveness condition'. But, ACEs fail to satisfy the condition. For this reason, I conclude that ACEs can't be a help to an agent's control over his intention and action.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.157-159
• /
• 2017

This paper presents a storage reliability evaluation method based on the accelerated degradation test for the engine assembly and parts of the guided missile. The test of the engine assembly is performed at accelerated conditions equivalent to the real storage period, and then the aging condition of parts is checked. For engine parts, performance degradation characteristics are measured periodically at the accelerated conditions and failure times are predicted at each condition. Storage lifetime at normal use conditions is predicted using an accelerated model and failure times at all accelerated conditions.

• Korean Journal of Logic
• /
• v.14 no.2
• /
• pp.105-121
• /
• 2011

The late professor Young-Jung Kim advanced a view that Existential Specification Rule (ES Rule) can be understood as a kind of polylemma. In arguing for this view, he also claimed that all propositions containing free variables are universal propositions. In this paper, I argue that his view on free variables incur numerous problems. Moreover, I introduce a new rule of inference called 'Universalized Conditionalization Rule' (UC Rule), so that I can show that his insight about ES Rule can be substantialized without an appeal to his problematic view on free variables. Finally, I show that ES Rule can be directly derived from UC Rule.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.303-303
• /
• 2020

국내의 주요 외곽시설은 대수심화 및 설계외력의 증대 등으로 경제성 및 안정성 등의 확보를 위해 혼성제 형식의 구조물을 적용하는 사례가 주를 이루고 있다. 혼성제 근고부 안정성과 관련해서는, 설계파에 대한 안정적인 피복재 중량을 구하는 것이 설계상 중요하다. 기존의 직각 입사파에 대한 연구는 많이 수행되어 왔으나, 경사 입사파 조건에 대한 검토 사례는 미미한 실정이다. 또한 직각입사 뿐만 아니라 경사 입사파에 대한 근고부 중량산정식으로 확장된 Tanimoto식을 적용하고 있으나, 수리실험과 중량산정식에 대한 오차가 발생하고 있어 수리실험을 통해 기존의 산정식에 대한 검토가 필요하다. 따라서 본 연구에서는 경사입사파 조건에 따른 혼성제 제두부 구간의 피복재 안정성에 대하여 실험을 수행하였다. 설치수심은 0.3m 수심으로 고정하고, 입사각도를 0°, 30°, 45°, 60° 및 75°로 변화시켜 실험을 수행하였다. 전체 연장 10m의 모형에서 종점부 1m 구간을 실험구간으로 설정하고, 피복재의 종류는 피복석(50g), 콘크리트 피복블록(Tetrapod, Tripod)를 사용하였으며, 파랑조건은 불규칙파를 적용하였다. 주기 및 파고를 변화시켜 수리실험을 수행하였다. 실험결과는 제두부 구간에 피복된 피복재의 구간별 피해율을 분석하기 위해 구역분할도 적용하였으며, 확장된 Tanimoto식과 비교분석하여 중량산정식의 타당성을 검토하였다.

• The KIPS Transactions:PartA
• /
• v.11A no.7 s.91
• /
• pp.483-488
• /
• 2004

For real-time applications, the underlying operating system (0S) should support timeliness guarantees of real-time tasks. However, most of current operating systems do not provide timely management facilities in an efficient way. There could be two approaches to support timely management facilities for real-time applications: (1) by modifying 0S kernel and (2) by Providing a middleware without modifying 0S. In our approach, we adopted the middleware approach based on the TMO (Time-triggerred Message-triggered Object) model which is a well-known real-tine object model. The middleware, named TMSOM (TMO Support Middleware) has been implemented on various OSes such as Linux and Windows XP/NT/98. In this paper, we mainly consider TMOSM implemented on Linux(TMOS/Linux). Although the real-time schedul-ing aIgorithm used in current TMOSM/Linux can produce an efficient real-time schedule, it can be improved for periodic real-time tasks by considering several factors. In this paper, we discuss those factors and propose an improved real-time scheduling algorithm for periodic real-time tasks, In order to simulate the performance of our algorithm, we measure timeliness guarantee rate for periodic real-time tasks. The result shows that the performance of our algorithm is superior to that of existing algorithm. Additionally, the proposed algorithm can improve system performance by making the structure of real-time middleware simpler.

• Journal of Plant Biotechnology
• /
• v.36 no.1
• /
• pp.7-12
• /
• 2009

This study was conducted to establish the optimal suspension culture system for both the propagation of embryogenic cells (ECs) and the induction of somatic embryos (SEs) of Kalopanax septemlobus. The proliferation rate of ECs was reduced as the inoculum density was increased; the highest rate was obtained when 0.1 g/100 ml of cells was initially inoculated. According to the analysis of cell growth pattern and cell growth cycle (G1, Sand G2/M), the cell growth started in 5 days culture initiation, grew rapidly until 15 days and then decreased gradually. Distinctive changes of the cell growth cycle by the culture periods was also observed; the growth cycle was doubled from initial 5.6% to 11.7% of S stage in 5 days culture and then reached in stable stages again. Therefore, the results indicated that a 15-day-cycle was the optimal culture period for the propagation of the ECs through the suspension culture. Furthermore, the cell inoculum density was also important for the induction of SE; more than 65% of SEs at the torpedo stage was induced by using the low level of cell inoculum (0.5 g/L), while the higher inoculum densities were rapidly reduced the proportion of SEs at that stage. Although the higher inoculum density delayed the development of SE, it did not affect the proportion of SEs at the globular and heart stage. In conclusion, this study showed that the suspension culture of the Kalopanax septemlobus ECs through the control of inoculum density was an efficient way for both the propagation of ECs and the induction of SEs, suggesting that the development of this system might help to reduce the culture period for the somatic embryo production.

• Journal of Korean Society of Forest Science
• /
• v.99 no.3
• /
• pp.414-422
• /
• 2010

The objective of this study was to find optimal water condition of containerized seedling production of two tropical species for high seedling quality. This study was conducted to investigate photosynthesis, water use efficiency(WUE), Stomatal conductance(gs) and growth performances of containerized seedlings of Eucalyptus pellita and Acacia mangium growing under three different irrigation periods (1 time/1 day, 1 time/2 days and 1 time/3 days). E. pellita showed outstanding photosynthetic capacities at 1time/1day irrigation and A. mangium showed good photosynthetic capacity at all treatments. As irrigation period were shortened, gs of two species increased, while WUE of two species decreased. Root collar diameter and height of two species were the highest at 1 time/1 day irrigation, while the lowest at 1 time/3 days irrigation. As irrigation period were shortened, H/D ratio, biomass and seedling quality index (DQI) of two species increased but T/R ratio of two species showed the opposite tendency. These results showed that 1 time/1 day irrigation is optimal water condition of containerized seedling production of two tropical species and irrigation controlling is very important for growth and seedling quality of containerized seedling.