• Journal of the Korean Data and Information Science Society
• /
• 제26권6호
• /
• pp.1295-1303
• /
• 2015

혼합물 실험으로부터 실험자는 주효과와 저차의 상호작용 효과의 추정을 원한다. 이를 위해 심플렉스 중심배열법과 같은 적절한 실험을 통해 추정할 수 있다. 그러나, 요인의 수가 늘어나면 부득이 일부실시를 행하게 된다. 이 경우 각 성분의 혼합비율의 합이 일정하다는 제약 조건은 교락으로 인해 추정가능한 상호작용의 선택을 어렵게 한다. 이러한 문제를 해결하기 위해 본 논문에서는 $Scheff{\acute{e}}$의 정준 모형 대신에 대수기하학을 기초로 한 동차다항식 (homogeneous polynomial)으로 구성된 모형을 도입하여 문제를 풀려고 한다. 이를 활용하여 심플렉스 중심배열법의 일부실시법에 대해 추정가능한 모형을 제시한다. 연산은 CoCoA 대수연산 소프트웨어를 이용하였다.

• 대한화학회지
• /
• 제62권3호
• /
• pp.235-242
• /
• 2018

본 연구는 우리나라와 뉴질랜드의 화학 교육과정을 비교 분석하였다. 양국은 교육과정을 통해 핵심 역량을 기르고자 함을 명시하고 있으며, 총론에서 제시한 핵심 역량이 서로 유사하였다. 우리나라는 과학 교과의 핵심 역량을 제시하였는데, 뉴질랜드가 과학의 본성 영역에서 제시한 4가지 성취 목표와 유사하였다. 특징적으로, 뉴질랜드는 교육과정 성취기준과 NCEA 성취 기준에서 핵심 역량을 함양할 수 있는 성취기준들이 별도로 제시하고 이를 내적 평가를 통해 학생들을 평가하고 있었다. 우리나라와 뉴질랜드의 고등학교 화학 과목에서 다루고 있는 개념은 유사하였는데, 화학I 과목의 경우 뉴질랜드의 교육과정 7단계에, 화학II 과목의 경우 뉴질랜드의 7~8단계에 해당하는 것으로 나타났다. 양국이 다루는 화학 내용에서 차이가 있는 개념은 탄화수소, 이상 기체 방정식, 총괄성, 분광학 데이터의 이해 등이었다.

• 약학회지
• /
• 제37권1호
• /
• pp.18-29
• /
• 1993

This study was initiated to investigate the effective action and mechanism of GE-132 (Carboxyethylgermanium sesquioxide)on benzo(a)pyrene, which have strong carcinogenicity and mutagenicity. To confirm desmutagenic effect (inhibition of metabolic processes of benzo(a)pyrene with S9 Mix or inactivation of the mutagenicity of benzo(a)pyrene metabolites) and antimutagenic effect (inhibition of gene-expression of reverted genes) of GE-132 against benzo(a)pyrene using with Salmonella typhimuyium TA98 Ames test was performed. The revertants in desmutagenicity test were decreased significantly in the combined groups of benzo(a)pyrene and GE-132 than benzo(a)pyrene only, without inhibition the metabolism of benzo(a)pyrene by S9 Mix. The ideal combined groups of benzo(a)pyrene and GE-132 were 10 $\mu{M}$ and 10mg, 20 $\mu{M}$ and 20mg, 100 $\mu{M}$ and 30 mg, respectively. Then, the revertants in antimutagenicity test, which was studied the direct action of GE-132 on the induction of revertant cells by Salmonella typhimurium TA98 and activated benzo(a)pyrene were decreased significantly in the treated groups of GE-132 than no treated groups. The number of revertants of Salmonella typhimurium TA98 were reduced with increasing amounts of GE-132. From the above results, it was found that GE-132 inactivated the mutagenic metabolites of benzo(a)pyrene without inhibition of the enzyme action in the S9 Mix, and GE132 showed antimutagenic effect which have inhibitory action of reverted gene expression.

• 대한예방한의학회지
• /
• 제14권3호
• /
• pp.107-115
• /
• 2010

Objectives : The purpose of this study is to investigate the efficacy of growth exercise program based on Korean medicine. Methods : We recruited fifty two elementary students in a rural area, and measured height, weight, BMI, WHR, and bone age. Questionnaire on sleep, exercise, symptoms based on Korean medicine was performed. Students exercised TaeGuk(太極) Health Gigong(氣功), a growth exercise program 11 times in 6 weeks. Results : Height, weight, BMI and WHR of the subject students were lower than those in the Korean CDC(Center for Disease Control and Prevention) growth chart. There was significantly negative correlation between time of sleep and bone age(p=0.028), but no correlation between time of exercise and bone age(p=0.668). According to diagnosis based on Korean medicine, many students were in weakness of spleen and lung, and bone age according to deficiency of organ showed no significant difference(p=0.774). Satisfaction, impact on time of exercise after program, ideal time for program and impact on reparticipation of program were strong in the questionnaire after growth exercise program(TaeGuk(太極) Health Gigong(氣功)). Conclusions : Korean medicine promotion of health has a salutary effect on elementary school students in rural area by collecting growth and health data and educating easy exercise based on Taichi.

• Environmental Analysis Health and Toxicology
• /
• 제22권3호
• /
• pp.211-218
• /
• 2007

Even though some standard developmental bioassay protocols for environmental assessment using sea urchins have already been described, there have not been many attempts to apply and modify these protocols with Korean species. Therefore, there is a strong need to establish standard bioassay protocols using sea urchins commonly found in Korea. Prior to developing a new protocol, it is essential to know the optimal conditions for the bioassay procedures. We investigated the optimal conditions (temperature, salinity, and embryo density) of the sea urchin Strongylocentrotus intermedius. The ideal temperature for developmental bioassay of S. intermedius was determined to be $15^{\circ}C$ and the time required for the embryo to become pluteus larva was 72 hr. The optimal range of salinity for the embryo toxicity using S. intermedius was between 30 to 32 psu, which is similar to the range found in the natural habitats of adult populations. The optimum density of embryos at the beginning of bioassays was 100 embryos/mL. When the assays were carried out at higher densities, the proportion of normally developed larvae decreased significantly.

• 한국안전학회지
• /
• 제26권3호
• /
• pp.69-74
• /
• 2011

Despite most of tasks in manufacturing, construction and agriculture, etc., were currently mechanized and automated, manual materials handling still existed in atypical working condition. In case of manual materials handling, repetitive work, inappropriate working posture, excessive force, contact stress might cause overload, which could lead to work-related musculoskeletal disorders and low back pains. On this basis, the goal of this study is to reveal the effects of various lifting postures of trunk angles and lower extremity postures on maximum holding time(MHT). Twenty two subjects were recruited from a university population. The experiment was designed by a combination of three trunk angle ($0^{\circ}$, $20^{\circ}$, $60^{\circ}$) and three lower extremity postures(straight, bent, kneeling). Before experimental trials, subjects performed MVC(maximum voluntary contraction) exertions in three trunk angles ($0^{\circ}$, $20^{\circ}$, $60^{\circ}$) to calculate 30%MVC at designated postures. In each trial, they were required to hold the handheld load(30%MVC) for a designated posture as long as they could. The results of MVC by trunk angles were measured in $0^{\circ}$ > $20^{\circ}$ > $60^{\circ}$ orders, but those of MHT measured in $20^{\circ}$ > $0^{\circ}$ > $60^{\circ}$ orders. These results showed that straight posture is the ideal working posture in work exerted a strong force for a short time, but the ability to work might be improved in the trunk angle $20^{\circ}$ in work required 30%MVC for a long time. Also, results of MVC and MHT by lower extremity postures measured in straight > bent > kneeling orders.

• Journal of Power Electronics
• /
• 제11권3호
• /
• pp.360-368
• /
• 2011

This paper proposes an active frequency with a positive feedback in the d-q frame anti-islanding method suitable for a robust phase-locked loop (PLL) algorithm using the FFT concept. In general, PLL algorithms for grid-connected PV PCS use d-q transformation and controllers to make zero an imaginary part of the transformed voltage vector. In a real grid system, the grid voltage is not ideal. It may be unbalanced, noisy and have many harmonics. For these reasons, the d-q transformed components do not have a pure DC component. The controller tuning of a PLL algorithm is difficult. The proposed PLL algorithm using the FFT concept can use the strong noise cancelation characteristics of a FFT algorithm without a PI controller. Therefore, the proposed PLL algorithm has no gain-tuning of a PI controller, and it is hardly influenced by voltage drops, phase step changes and harmonics. Islanding prediction is a necessary feature of inverter-based photovoltaic (PV) systems in order to meet the stringent standard requirements for interconnection with an electrical grid. Both passive and active anti-islanding methods exist. Typically, active methods modify a given parameter, which also affects the shape and quality of the grid injected current. In this paper, the active anti-islanding algorithm for a grid-connected PV PCS uses positive feedback control in the d-q frame. The proposed PLL and anti-islanding algorithm are implemented for a 250kW PV PCS. This system has four DC/DC converters each with a 25kW power rating. This is only one-third of the total system power. The experimental results show that the proposed PLL, anti-islanding method and topology demonstrate good performance in a 250kW PV PCS.

• Journal of Korean Neurosurgical Society
• /
• 제30권sup1호
• /
• pp.73-78
• /
• 2001

Objective : Intraoperative rupture of an intracranial aneurysm can interrupt a microsurgical procedure and jeopardize the patient's chance to favorable outcome. The purpose of this study was to analyse and evaluate intraoperative aneurysmal rupture and render ideal prevention and management to intraoperative rupture. Patients and Methods : The authors retrospectively analysed the results of 609 patients who underwent cerebral aneurysm surgery from January 1991 to December 2000. Results : 1) Intraoperative aneurysmal rupture occurred in 73 of 609 consecutive aneurysm surgery, so the incidence was about 12.0% and it was relatively lower than other reports. 2) Aneurysms arising from anterior communicating artery appeared more prone to intraoperative rupture. 3) The size of aneurysm and timing of operation didn't influence intraoperative aneurysmal rupture and temporary clipping didn't reduce the incidence of intraoperative aneurysmal rupture. 4) Intraoperative aneurysmal rupture occured during three specific periods : (1) dissection stage in 61%, (2) clip application stage in 29 %, (3) predissection stage in 10%. 5) In the patients with intraoperative aneurysmal rupture, surgical outcome was relatively good and there was no significant difference in outcome compared with unruptured group. Conclusion : Our suggestion for prevention methods of intraoperative aneurysmal rupture are as follows : 1) minimal brain retraction, 2) sharp and careful aneurysmal neck dissection, 3) gentle clipping with proper clip selection etc. Management methods after intraoperative aneurysmal rupture are as follows : 1) strong aspiration of bleeding point, 2) rapid application of temporary and/or tentative clip, 3) following rapid dissection of neck and proper clip application, 4) use of encircling clip etc.

• 디지털융복합연구
• /
• 제17권10호
• /
• pp.439-446
• /
• 2019

한국 문화 전반에 성 평등을 주제로 한 페미니즘이 중요한 이슈로 연구 대상적 가치가 급상승하였다. 페미니즘 영화란 단지 여성의 권익을 주장하거나 옹호하는 차원의 수준이 아닌 과거 남성들이 창조한 스토리 속에서 대상화되거나 타자화 된 인물로 왜곡, 인위적으로 묘사되던 그릇된 여성의 모습이 아닌 시선과 사고의 본질적 주체로서 사회 속 개인의 삶의 문제를 근원적으로 탐구하는 영화라고 할 수 있다. 이와 같은 관점에서 전고운 감독의 영화 '소공녀(2018)'를 분석하였으며 영화 속에는 남성 편향적 고정관념과 불평등적 사회구조에도 주인공의 꿋꿋한 자기 선택과 초월적 사고를 보여주는 페미니즘 적인 주제를 표현하고 있음을 알 수 있었다. 대중영화가 세상에 대한 넓은 식견을 키우는 교육 계몽적 성격을 견지하고 성숙한 사회문화를 선도해야 한다는 관점에서 이와 같은 사회에 대한 전지적 통찰과 이상적 인간관에 대한 제고 등을 다룬 영화는 사회를 긍정적이고 이상적으로 바꾸는 데 큰 역할을 할 것이라고 생각된다.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년 영문 학술대회
• /
• pp.16-21
• /
• 2008

Aero-engine, as one kind of rotating machinery with complex structure and high rotating speed, has complicated vibration faults. Therefore, condition monitoring and fault diagnosis system is very important for airplane security. In this paper, a vibration data acquisition and intelligent fault diagnosis system is introduced. First, the vibration data acquisition part is described in detail. This part consists of hardware acquisition modules and software analysis modules which can realize real-time data acquisition and analysis, off-line data analysis, trend analysis, fault simulation and graphical result display. The acquisition vibration data are prepared for the following intelligent fault diagnosis. Secondly, two advanced artificial intelligent(AI) methods, mapping-based and rule-based, are discussed. One is artificial neural network(ANN) which is an ideal tool for aero-engine fault diagnosis and has strong ability to learn complex nonlinear functions. The other is data mining, another AI method, has advantages of discovering knowledge from massive data and automatically extracting diagnostic rules. Thirdly, lots of historical data are used for training the ANN and extracting rules by data mining. Then, real-time data are input into the trained ANN for mapping-based fault diagnosis. At the same time, extracted rules are revised by expert experience and used for rule-based fault diagnosis. From the results of the experiments, the conclusion is obvious that both the two AI methods are effective on aero-engine vibration fault diagnosis, while each of them has its individual quality. The whole system can be developed in local vibration monitoring and real-time fault diagnosis for aero-engine.