• 한국지하수토양환경학회지:지하수토양환경
• /
• 제22권2호
• /
• pp.26-32
• /
• 2017

Regression analyses were conducted for prediction of benzo(a)pyrene (BaP) and total polycyclic aromatic hydrocarbons (PAHs) in soils. Dimensionless units were applied after each PAH was divided by naphthalene (Nap) for the regression analyses using a previously published Swiss data set or all data sets, including Chinese and Brazilian. A strong correlation was found between BaP/Nap ($R^2=0.95$) or ${\Sigma}PAH/Nap$ ($R^2=0.99$) and Pyr/Nap ratios from the Swiss data set. When the developed prediction equation was applied to other measurements to validate its accuracy, there was great agreement between the data and predicted values. This model could be used as a useful tool for the calculation of average BaP and ΣPAH in specific regions without additional tests.

• 대한인간공학회지
• /
• 제30권3호
• /
• pp.409-418
• /
• 2011

Objective: This study was performed to evaluate the child-care teachers' job in relation to physical work. Background: Child-care teacher is directly related to the quality of child care. And their physical activity is higher than general education teachers because the proportion of day care is high. But analyzes of child-care teachers' job burdens and the work environment associated with physical activity is not well established. Method: To conduct this study, the child-care teachers' job was classified into 18 physical works. After classification, posture was evaluated by ergonomic posture evaluation schemes of OWAS, RULA, REBA and evaluated for each physical part. Next, musculoskeletal subjective symptoms were analyzed. Results: The results showed the following: The highest assessment on the posture evaluation was "helping children to ride a school bus", "feeding: meal/snack", "brushing children's teeth" and "arrangement of nap-stuff". The rank of high-risk assessment on the neck/trunk/leg part was arranged by: "feeding: meal/snack", "helping children to ride a school bus", "making nap", "arrangement nap-stuff" and "brushing children's teeth". The rank of high-risk assessment on the upper limbs part was arranged by: "helping children to ride a school bus", "the bust - group activity", "meal/snack time - preparing, feeding, arrangement", "nap time - preparing, arrangement", "brushing children's teeth", and "using the toilet". According to the results of each musculoskeletal subjective symptom, teachers ordered the pain area as follows: waist, shoulder, leg/feet, and neck, and they showed more pain on trunk than the upper limbs. Conclusion: To sum up the results from ergonomic posture evaluation and a subjective symptom, the following are high working pressures: "feeding: meal/snack", "the bust - group activity", "making nap", "brushing children's teeth" with deep bending and waist twisting, "helping children to ride a school bus", "brushing children's teeth" with lifting shoulder; "meal/snack time - preparing, arrangement", "nap time - preparing, arrangement", and "using the toilet" with moving or an up-down position in their job. Application: The results of this study might be information for improvement of the child-care teachers' job environment.

• 정보처리학회논문지C
• /
• 제15C권6호
• /
• pp.547-556
• /
• 2008

최근 컴퓨팅 기술과 네트워크 기술의 발전으로 초고속 인터넷의 보급되고 있지만 인터넷에서 높은 대역폭을 필요로 하는 미디어를 스트리밍하는 것은 아직 매우 어려운 일이다. 기존의 인터넷 기반 스트리밍에 관한 연구들에서는 네트워크의 변화에 따라 적응적으로 QoS(Quality of Service)를 조절하는 기법들을 제시하여 왔다. 하지만 이는 서비스 제공자 입장에서의 문제 해결이며 네트워크 상태에 상관없이 일정한 QoS를 원하는 사용자에게는 적합하지 않다. 본 논문에서는 네트워크 상태에 따라 적응적으로 동작하는 프리페칭을 통하여 일정한 QoS를 보장하고자하는 NAP(Network Adaptive Prefetching)기법을 제안한다. 제안하는 NAP기법은 네트워크의 가용한 대역폭이 높을 경우 프레임 재생율보다 빠르게 프레임을 전송시키는 방식으로 프리페칭을 한다. 이렇게 프리페칭된 프레임은 대역폭이 낮아지는 경우에 QoS를 일정한 수준으로 유지하는데 사용된다. 실험을 통하여 비디오 스트림의 특성을 분석하였으며 이를 바탕으로 네트워크 상태에 따라 적응적으로 프리페칭을 함으로써 기존 방식에 비해 QoS를 일정하게 유지할 수 있음을 보였다.

• 대한산업공학회지
• /
• 제30권3호
• /
• pp.181-189
• /
• 2004

The purpose of this study was to investigate the effects of sleep/wake behavior for shift workers in the iron and steel industry using wrist actigraph for 59 male workers on a continuous full-day three-team three-shift system of backward rotation including on-duty and off-duty periods. The wrist actigraph data were recorded for 15 days (l shift cycle) for each subject. The sleep length at home during night shift decreased significantly as compared to the morning or evening shifts. The night shift nap length increased significantly in all sections as compared to the morning or evening shifts. The nap length in the Steel Manufacturing Process and Rolling Process during night shift decreased significantly as compared to the Machine Maintenance Section, the Forwarding of Products Section, and the Field Management Section. However, the sleep length at home while off-duty period increased significantly. The percentage of nap length during night shift in the Rolling Process, Steel Manufacture Process, and the other three types of jobs was 16.0%, 20.4%, and about 50.0%, respectively. The nap length during night shift for the above 50 year olds increased significantly as compared to the below 50 year olds. Finally, we discussed the role of nap-taking during the burden on night shift workers and the increased difficulty in continuing their job.

• 미생물학회지
• /
• 제54권1호
• /
• pp.1-8
• /
• 2018

원핵 세포는 핵양체 결합 단백질(NAP)로 알려진 다양한 히스톤 유사 단백질을 가지고 있다. 이들은 DNA의 AT-rich 서열에 결합하여, DNA 자체를 감싸거나, 구부리거나, 떨어져 있는 DNA 가닥을 연결시키는 다리 역할을 하여, 결국에는 원핵 생물의 유전자 발현을 조절한다. NAP는 특히 전사의 억제 기능을 가지고 있기 때문에, 유전자 발현 억제에 있어서 이들의 역할과, 구체적인 메커니즘을 밝히는 것을 매우 중요한 일이다. 본 논문에서는 잘 알려져 있는 NAP인 H-NS와 HU에 대하여 정리하였고, 특히 E. coli와 Salmonella Typhimurium에서 이들의 유전자 발현에 대한 기능을 요약하였다. H-NS는 이들의 올리고머화와 필라멘트 구조 형성을 통하여 Salmonella와 같은 사람에 감염하는 병원성 세균의 독성유전자 발현을 억제할 수 있고, 이런 기능을 수행하였을 때 다른 NAP와 함께 작용할 수 있다. 최근에 H-NS는 사람에게 typhoid fever와 systemic disease를 발생시키는 독성물질인, typhoid toxin의 발현 또한 조절할 수 있음이 밝혀졌다. Salmonella에서 HU 또한 독성 유전자뿐만 아니라, 이들의 생리적 기능에 중요한 유전자들의 발현을 조절할 수 있다. 따라서, H-NS와 HU와 같은 NAP들이 원핵 생물의 독성 유전자 발현의 분자적인 메커니즘을 밝히는데 중요한 요소임을 제시한다.

• 한국정밀공학회지
• /
• 제14권5호
• /
• pp.85-91
• /
• 1997

Air grinding time in grinding process has a great effect on its efficiency due to low feedrate. This paper presents a reduction methos of air grinding time in cylindrical plunge grinding operation. Tje reduction of air grinding time is accomplished by finding the distance between contact point and rising point of ultra- sonic signal of the grinding wheel to workpiece. It uses a variation of sound signal generated by the flow of coolant when the grinding wheel approaches to workpiece. The ultrasonic sensor with 23 kHz center fre- quency and 8 kHz bandwidth is used to find the nearest approaching point(NAP). Monitoring and control system of the grinding conditions is implemented with CNC controller to control feedrate override and ultrasonic sensor to find NAP. The experimental result shows that the ultrasonic signal is a good measure- ment to find NAP. But it needs the considerations for the effect of the relationship between flowrate of coolant and diameter of workpiece.

• 한국의사학회지
• /
• 제13권2호
• /
• pp.23-28
• /
• 2000

As a result of examination and analyzing variety of bibliographies, "Un hae nap yak zung chi bang" that has been known as anonymous work, is thought to be the work of Hur jun.

• 상하수도학회지
• /
• 제28권4호
• /
• pp.419-429
• /
• 2014

Recent studies have been reported the presence of Endocrine Disrupting Compounds, Pharmaceuticals and Personal Care Products (EDC/PPCPs) in surface and wastewater, which could potentially affect to the complicate behavior in coupled presence of nano-colloid particles and surfactants (adsorption, dispersion, and partitioning). In this study, the adsorption of EDC/PPCPs by Single Walled Carbon Nanotubes (SWNTs) as a representative of nano-particles in cationic surfactant solutions were investigated. Hydrophobic interactions (${\pi}-{\pi}$ Electron Donor-Acceptor) have been reported as a potential adsorption mechanisms for EDC/PPCPs onto SWNTs. Generally, the adsorptive capacity of the relatively hydrophobic EDC/PPCPs onto SWNTs decreased in the presence of cationic surfactant (Cetyltrimethyl Ammonium Bromide, CTAB). This study revealed that the competitive adsorption occurred between CTAB cations and EDC/PPCPs by occupying the available SWNT surface (CTAB adsorption onto SWNTs shows five-regime and maximum adsorption capacity of 370.4 mg/g by applying the BET isotherm). The adsorption capacity of $17{\alpha}$-ethinyl estradiol (EE2) on SWNT showed the decrease of 48% in the presence of CTAB. However, the adsorbed naproxen (NAP) surely increased by forming hemimicelles and resulted in a favorable media formation for NAP partition to increase SWNTs adsorption capacity. The adsorbed NAP increased from 24 to 82.9 mg/g after the interaction of CTAB with NAP. The competitive adsorption for EDC/PPCPs onto SWNTs is likely to be a key factor in the presence of cationic surfactant, however, NAP adsorption showed a slight competition through $CH_3-CH_3$ interaction by forming hemimicelles on SWNT surface.

• 복식문화연구
• /
• 제17권5호
• /
• pp.746-757
• /
• 2009

This study is focused on the elucidation of efficient and correct marking methods by comparing and analyzing marker efficiency depending on the marking job condition such as interval of checking-pattern, width of materials, and marker orientation using man's shirts. To compare the marking efficiency of shirts, plain and check-patterned materials with the intervals of $1.5{\times}1.5cm$, $3{\times}3cm$, and $5{\times}5cm$ were selected. First, in the comparison of marking efficiency depending on materials width, the highest efficiency was obtained with nap-either-way position of 150cm, plain materials and lowest efficiency with nap-one-way position of 150cm, $5{\times}5cm$ check-pattern materials. Regardless of the direction of marker position, the marking efficiency of 150cm width was higher than 110cm width in the plain, $1.5{\times}1.5cm$ and $3{\times}3cm$ check-pattern interval, but the marking efficiency of 110cm width was higher than 150cm width in the $1.5{\times}1.5cm$ check-pattern interval. Second, in the comparison of marking efficiency depending on the direction of marker position, regardless of check-pattern interval and material width, the highest efficiency was obtained with nap-either-way position. And nap-up-and-down and nap-one-way follows next. Third, in the comparison of marking efficiency depending on check-pattern interval, the efficiency of plain materials was higher than those of check-patterned materials. And increasing the intervals decreased marking efficiency and vice versa. So the lowest efficiency was obtained with $5{\times}5cm$ check patterned materials.

• 한국보육지원학회지
• /
• 제9권5호
• /
• pp.335-355
• /
• 2013

본 연구는 아동권리 존중 측면에서 어린이집에서의 휴식 및 낮잠에 대한 유아들의 인식과 요구는 무엇인지 알아보는 것이 목적이다. 연구대상은 서울시 국공립 B어린이집 원아 만4세 20명, 만5세 20명으로 총40명이다. 연구방법은 면담조사와 프로젝트활동 중에서 참여관찰로 이루어졌으며 이 과정에서 수집한 관찰기록, 녹음자료, 동영상자료의 전사본을 내용분석 하였다. 연구결과로 첫째, 유아가 인식하는 휴식의 의미는 가족과 함께 하는 시간, 재미있는 놀이하는 시간, 힘들고 화날 때 필요한 시간, 맛있는 음식을 먹는 시간으로 나타났으며 둘째, 어린이집에서의 낮잠에 대해 유아들은 자기 싫은데도 자야하는 시간, 조용한 음악 듣는 시간, 자고나면 기분이 좋아지는 시간으로 인식하였으며 셋째, 어린이집에서의 휴식 및 낮잠에 대해 유아들은 친구들이 귀가 후 종일반에 모였을 때 쉬고 싶어 하였으며, 교실 외 별도의 공간을 필요로 하고, 휴식할 때 친숙한 성인의 보호를 요구했다. 이 결과를 통해 유아들의 휴식 및 낮잠을 즐길 수 있는 권리를 존중하는 측면에서 향후 연구방향을 제안하였다.