Earticle

개정된 ICT교육지침에는 알고리즘, 자료구조, 프로그래밍 내용과 같은 컴퓨터과학 요소가 매우 강화되었다. 또한 최근 교육과학기술부는 STEAM 교육을 강조하고 있다. 여기에서 가장 중요한 문제는 “어떠한 방법으로 가르쳐야 하는가?”이다. 즉, 교수학습 콘텐츠의 개발이 필요하다. 그래서 본 논문에서는 레고 마인드스톰 NXT 교육용 로봇을 활용한 스택과 큐 학습 방안을 제시한다. 주된 목표는 로봇이 미로라는 현실적인 구조물을 탐색할 때 스택과 큐가 어떻게 사용되는지를 보여주는 것이다. 교수학습 전략으로는 알고리즘 작성, 순서도, NXT-G 프로그래밍으로 정하였다. 단순한 미로는 왼쪽과 오른쪽 중 어느 한쪽에만 길이 있는 미로이고, 복잡한 미로는 삼거리가 포함된 미로이다. 이 두 개의 미로는 직접 개발하여 제작하였다. 마스터 로봇은 미로의 출구까지 탐색하면서 경로를 스택에 저장한 후, 이 스택을 이용하여 다시 입구까지 되돌아온다. 또한 마스터 로봇은 미로를 탐색하면서 경로를 실시간으로 슬레이브 로봇의 큐에 전달한다. 그 후 슬레이브 로봇은 큐에서 경로를 꺼내어 탐색없이 미로를 주행한다. 로봇의 미로 탐색이라는 미션을 해결하는 과정에서 학습자들은 스택과 큐의 활용 분야를 자연스럽게 이해하게 된다. 이러한 수업을 통해서 학습자들의 논리적인 사고력과 창의력이 향상되고, ICT 교육과 STEAM 교육에도 적용이 가능하리라 기대된다.

ICT education guidelines revised in 2005 reinforce computer science elements such as algorithm, data structure, and programming covering all schools. And Ministry of Education emphasizes STEAM education. Most important is that "How instruct them". This means necessity of contents. So this paper suggests learning method of Stack and Queue using LEGO MINDSTORMS NXT. The main purpose is that how stack and queue are used, when robot explore realistic maze. Teaching and learning strategies are algorithm, flowchart, and NXT-G programming. Simple maze has path in left or right, but complex maze has three-way intersection. These are developed by authors. Master robot explores maze and push stack, and then return to entrance using stack. Master robot explores maze and transmits path to slave's queue. And then slave robot drives without exploration. Students can naturally learn principles and applications of them. Through these studies, it can improves ability of logical and creative thinking. Furthermore it can apply to ICT and STEAM education.

When developing a software engineering project, selecting the most appropriate programming language is a crucial step. Most often, feeling at ease with the possible options becomes almost as relevant as the technical features of the language. Therefore, it appears to be worth analyzing the role that the emotional component plays in this process. In this article, we analyze the trend of the emotions expressed by developers in 2018 on the Stack Overflow platform in posts concerning 26 programming languages. To do so, we propose a learning model trained by distant supervision and the comparison of two different classifier architectures.

The interoperability concerns horizontal integration among IoT devices which form vendor- or protocol-specific silos. To answer, this brief presents an architectural design of an autonomic interoperability manager (AIM) that is capable of self-configuration, self-healing, self-optimization, and self-protection. With AIM, IoT devices having diverse protocols, syntax, and semantics can collaborate and interact, and its plugin-based autonomic, service-oriented architecture ensures scalability and extendability. We simulated a healthcare use-case with a range of virtual IoT devices to demonstrate that the AIM dramatically reduces the average response time in a highly dynamic environment, by proactively pruning the network traffic and optimizing the compute resources.

본 연구는 데이터 시각화 과정에서 사용자의 관심 뷰(View)를 관리하고, 공간적 맥락을 유지할 수 있도록 지원하는 새로운 탐색 보조 도구인 CSN(Contextual Stack Navigator)을 제안한다. 기존 스냅샷 기반 방법은 데이터 탐 색 과정에서 생성된 뷰 간의 관계를 효과적으로 파악하기 어렵고, 맥락 정보의 부족으로 인해 사용자의 인지적 부담 을 증가시키는 한계가 있었다. 이를 극복하기 위해 CSN은 탐색 과정에서 생성된 뷰를 계층적 구조로 저장하고, 시 각적 단서를 통해 사용자에게 명확한 맥락 정보를 제공한다. CSN은 데이터 표현 방식에 제한받지 않고 다양한 데 이터 분석에 적용 가능하며, 탐색 과정에서의 직관적 상호작용과 유연한 데이터 분석을 지원한다. 본 연구에서는 CSN의 유용성을 검증하기 위해 저수준 작업 분류(Low-level Task Taxonomies)에 기반한 사례 연구를 수행하 였으며, 이를 통해 CSN이 기존의 스냅샷 방식 대비 탐색 효율성과 맥락 유지 측면에서 효과적임을 입증하였다. 본 연구 결과는 복잡한 데이터 분석 환경에서 시각적 탐색과 인사이트 도출을 효과적으로 지원할 것으로 기대된다.

This study proposes a novel navigation aid tool called Contextual Stack Navigator (CSN), designed to manage users' views during data visualization and preserve spatial context. Traditional snapshot- based methods have limitations in effectively identifying relationships between views generated during data exploration, often increasing users' cognitive load due to the lack of contextual information. To address these challenges, CSN stores views generated during the exploration process in a hierarchical structure and provides users with clear contextual cues. CSN is not constrained by data representation types, making it applicable to a wide range of data analysis scenarios while supporting intuitive interactions and flexible data exploration. To validate the utility of CSN, we conducted case studies based on Low-level Task Taxonomies, demonstrating that CSN is more effective than traditional snapshot methods in terms of exploration efficiency and context retention. These findings suggest that CSN can effectively support visual exploration and insight generation in complex data analysis environments.

현재 사이버 공격과 보안 위협은 지속적으로 진화하고 있으며, 조직은 신속하고 효율적인 보안 대응 방법을 필요로 한다. 본 논문은 Unified Threat Management (UTM) 장비를 활용하여 네트워크 보안을 향상시키고, 이러한 장비를 통해 수집되는 내부망의 로그 데이터를 Elastic Stack (Elasticsearch, Logstash, Kibana, 이하 ELK Stack)을 활용하여 효과적으로 관리하고 분석하는 내부망 보안 강화방안을 제안하고자 한다.

Currently, cyberattacks and security threats are constantly evolving, and organizations need quick and efficient s ecurity response methods. This paper proposes ways to strengthen internal network security by utilizing Unified T hreat Management (UTM) equipment to improve network security and effectively manage and analyze the log data of the internal network collected through these equipment using Elastic Stack (Elasticsearch, Logstash, Kibana, her einafter referred to as ELK Stack).

1969년에 발간된 API521 1st edition에서는 Flare Load 저감용으로 적용되는 HIPS (High Integrity Protection System)는 모 두 Pressure Safety Valve의 고장확률보다 낮은 SIL 3 (Safety Integrity Level)등급을 적용할 것을 요구하고 있다. Flare Stack 저감용 HIPS는 주로 압축기 출력압력상승, Reboiler Steam 과다주입, 전력공급중단냉각펌프고장 등에 의한 Flare 발생을 예방 하기 위한 기능을 가진 SIF (Safety Instrumented Function)로 구성된다. 하지만 2007년도 발간된 API521 5th edition에서는 LOPA (Layer Of Protection Analysis) 분석을 통해 Target SIL을 도출하는 것으로 요구사항을 변경했다. 이에 따라 이번 연구에서는 Flare Load에 가장 큰 영향을 미치는 시나리오 중 대표적인 시나리오를 대상으로 HAZOP (Hazard and Operability Study)과 LOPA분석을 실시해서 Target SIL이 어떻게 도출되는지를 연구했다. Flare Stack에서 Flare 를 발생시키는 대표적인 시나리오들에 대해 LOPA분석을 실시한 결과 압축기 출력압력상승은 SIL 2, Reboiler Steam 과다주 입은 SIL 3, 전력공급중단은 SIL 0, 냉각펌프고장은 SIL 0로 모두가 SIL 3 가 나오지는 않았다. SIF 설계 시 Target SIL을 만족시 키는 것도 중요하지만 운전 시 SIL 등급이 계속 유지되게 하지 위해 인적오류, 시스템적 고장, 하드웨어고장 등에 의해 SIF 기능 불능화가 되는 것을 예방하기 위한 기능안전관리시스템 (FSMS)를 적용하는 것도 중요하다.

New results of dependence of magnetic field, trapped by a stack of HTS tapes, on amount of tapes in a stack are reported. Commercial GdBCO tape 12 mm width and without Cu layer was used for the research. Tape was divided in square pieces 12 x 12 mm2 from which stacks were formed. Filling factor of the tape was about 1.4%. Measurements were carried out for stacks with height from 5 to 250 pieces and at wide temperature range from liquid helium to liquid nitrogen. Both FC (field cooling) and ZFC (zero field cooling) cooling methods were used in the research. These two methods show matching results with good accuracy. As a result dependences of trapped magnetic flux on amount of tapes for different temperatures were received. Research shows, that with increasing height of the stack trapped magnetic field value reach saturation at about 60 tapes in a stack for low temperatures. From 60 to 100 tapes increase of magnet flux is only 5%. Thus increase amount of tapes in a stack is not profitable. Also investigation of trapped magnet field relaxation was carried out. Relaxation speed decreases with increasing amount of elements. It means that the higher the stack is, the longer trapped flux will be held in cause of the same temperature.

It is the basic requirement of product characteristics to specify geometric dimensions and tolerances during design process of parts assembly. Therefore, there are many tolerance stack analysis method to explain tolerance zone. Tolerance stack analysis is to calculate gap using tolerances which includes geometric and coordinate dimension. In this study, we compared several different stack analysis method and try to suggest more general method called the Virtual Method to analyze tolerance stack.

Fong and Ginsburg (2013, 2014) propose a new theoretical framework for Agree relations, namely the stack mechanism. Its core idea is the stack. It is a kind of buffer which stores Syntactic Objects with an unvalued feature temporarily. The stack mechanism is argued to be more economical than the probe-goal search of Chomsky (2001) because, with the stack, there is no need for a probe to check all of the labels within its search domain. Fong and Ginsburg (2013) try to make their stack mechanism empirically motivated by demonstrating that it can successfully account for the notorious violin-sonata paradox. Their analysis, however, has two drawbacks: the indetermination of stack order in the case of doubling constituents and the wrong assumption that there is no A'-movement in tough constructions. To solve these problems, this paper suggests the A-over-A Constraint on Stack Order, and shows that Hicks’ (2009) doubling structure is more appropriate for doubling constituents. With these minor modifications, the stack mechanism is still a viable solution for the notorious violin-sonata paradox.

본 연구에서는 대기오염도 측정 및 TMS 설치가 불가능한 국내 플레어스택의 실태조사와 석유정제품 제조업 분야 플레어 스택의 적정 운영방안 마련을 위한 플레어스택의 연소발열량 기준 검토와 스모크리스 모니터링 시스템(smokeless monitoring system)을 이용한 플레어스택의 연소효율을 측정결과와 기존 측정방법(광학가스탐지카메라 및 매연 측정법)과 비교 평가하 고, 스팀분사량, 연소공기비 등에 따른 연소효율을 조사하여 배출가스 완전연소 조건 마련을 통한 대기오염물질 배출량 저감 유도 및 플레어스택의 적정운영 관리방안을 마련하고자 하였다. 국내 및 미국 EPA의 플레어스택의 비산배출 시설관리 기준 은 발열량 기준으로 스팀보조·혼합공기 보조방식 2,403 kcal/Sm3 이상, 연소용 공기 보조방식 196kc al/Sm3 이상이며, 국내 5 대 정유사는 36개 플레어스택 운영하고 있으며 석유정제업 36개 시설의 평균 연소효율은 92.8%로 화염 및 매연 발생 등 민 원 저감을 위해 과량의 스팀을 사용하고 있었다. 국내의 8개 플레어스택 시설의 적정 운영조건을 도출한 결과 연소효율은 8.6% 증가하였고, 스팀분사량은 시간당 2.5 ton 감소하는 것으로 나타났으며, VCU 연소공기비에 따른 연소효율은 연소 공기 비 45%일 때 연소효율은 88% ~ 91% 정도로 나타났다. 대기 배출시설인 플레어스택의 운영은 인위적으로 배출시스템의 변 경이 가능하므로 최대한 VOCs 물질이 적게 배출되도록 연소효율을 최대로 높여 운영할 필요가 있으며, 완전연소시 발생하 는 플레어스택의 배출형태에 대한 적정 운영방안 홍보 및 국민 인식 전환이 필요하다. 또한 플레어스택의 연소효율(발열량 등)을 정확하게 측정 및 모니터링 할 수 있는 시료채취 및 화학성분 측정방법의 도입이 필요할 것으로 판단되었다.

In this study, the combustion efficiency of the flare stack facility in the domestic petroleum refining industry was measured, and measures to improve the combustion efficiency of the flare stack were reviewed. When the flare stack in the domestic petroleum refining industry was operated, there were many parts where the amount of gas and steam was not measured, and when discharging, rather than the combustion efficiency, it was discharged so as not to visually disgust the surrounding. The flare stack combustion efficiency of the petroleum refining industry was found to be 68.8~99.9%, and the average combustion efficiency was 92.8%, which did not reach the 95% combustion efficiency standard for complete combustion. For facilities where the steam injection amount can be adjusted, the flare stack combustion efficiency increased by 4.1% on average as the amount of steam decreased by 2.3 ton/hr on average. This means that the average steam reduction amount is 2.5 ton/hr, and the steam cost is 30,000 won/ton, which is estimated to have an annual reduction of 650 million won in operating costs per flare stack. Since the flare stack, which is an air emission facility, can be artificially changed, it is necessary to increase the combustion efficiency to the maximum so as to discharge as little VOCs as possible, and to operate the flare stack generated during complete combustion. It is necessary to promote the plan and change public awareness. In the future, it is necessary to prepare an appropriate operation plan and facility management standard (draft) for the flare stack in consideration of combustion efficiency.

AC Losses for face to face stacks of four identical coated conductors (CCs) were numerically calculated using the H-formulation combined with the E-J power law and the Kim model. The motive sample was the face to face stack of four 2 mm-wide CC tapes with 2 μm thick superconducting layer of which the critical current density, Jc, was 2.16×106 A/cm2 on IBAD-MgO template, which was suggested for the mitigation of ac loss as a round shaped wire by Korea Electrotechnology Research Institute. For the calculation the cross section of the stack was simply modeled as vertically aligned 4 rectangles of superconducting (SC) layers with E = Eo(J(x,y,t)/Jc(B))n in x-y plane where Eo was 10-6 V/cm, Jc(B) was the field dependence of current density and n was 21. The field dependence of the critical current of the sample measured in four-probe method was employed for Jc(B) in the equation. The model was implemented in the finite element method program by commercial software. The ac loss properties for the stacks were compared with those of single 4 cm-wide SC layers with the same critical current density or the same critical current. The constraint for the simulation was imposed in two different ways that the total current of the stack obtained by integrating J(x,y,t) over the cross sections was the same as that of the applied transport current: one is that one fourth of the external current was enforced to flow through each SC. In this case, the ac loss values for the stacks were lower than those of single wide SC layer. This mitigation of the loss is attributed to the reduction of the normal component of the magnetic field near the SC layers due to the strong expulsion of the magnetic field by the enforced transport current. On the contrary, for the other case of no such enforcement, the ac loss values were greater than those of single 4cm-wide SC layer and . In this case, the phase difference of the current flowing through the inner and the outer SC layers of the stack was observed as the transport current was increased, which was a cause of the abrupt increase of ac loss for higher transport current.

In recent years, the interaction force between a permanent magnet and a closed superconductor coil has been gradually investigated in depth. The principle and application potential of an energy storage/convertor composed of a magnet and a closed superconducting coil have been proved. However, the study on the force between a magnet and a non-closed superconducting coil (superconducting roll stack) has hardly been reported in previous literature. The behavior of this kind of interaction and its influence to the interaction force between a permanent and a closed superconducting coil are also still unclear. In this paper, first we investigated the interaction force between a magnet and a superconducting roll stack. Then, a series of experiments were designed and conducted to clarify the factors affected the interaction force, including the geometrical parameters of the superconducting roll stack and the magnetic field density at the roll stack. Moreover, the comparison of the interaction forces between the magnet and roll stack or a closed coil was also introduced.

Donald K. Sebera 모델은 다른 열화인자의 영향을 고려하지 않고 오직 온도와 습도만의 변화를 이용하여 두 개 이상의 서고환경에 대한 보존성 평가지수를 계산함으로서 기록물의 보존환경을 정량적으로 비교․평가하는데 활용될 수 있다. 본 연구에서는 Donald K. Sebera 모델을 이용하여 기록물관리법에서 제시하고 있는 온․습도 범위에서 종이기록물 보존조건 중 가장 우수한 조건과 가장 열악한 조건에서의 보존성을 비교·분석하였다. 그 결과 기록물관리법에서 허용하고 있는 온․습도 범위 내에서 보존조건이 가장 우수한 조건에서의 종이기록물 보존성 평가지수가 가장 열악한 조건에서 보다 2.47배 더 큰 것으로 나타났다. 또 가수분해반응 활성화에너지가 작을수록 종이기록물의 보존성은 온도보다는 습도에 의한 영향력이 크게 작용하였다. 따라서 보존성 평가지수는 서고의 온ㆍ습도 조건이 기록물 보존환경에 적합한지를 쉽게 판단할 수 있기 때문에 온ㆍ습도 변화에 대해 보존성 확보가 가능한 도구로 유용하게 활용될 수 있다.

Donald K. Sebera model can quantitatively compare the preserving environment by calculating the preserving valuation index with changing only the temperature and humidity. In this study, Donald K. Sebera model was used in order to compare and evaluate the preserving valuation index on the best condition and the worst condition in the temperature and humidity range of public records management act. As the results, the preserving valuation index in the best conditions was larger 2.47 times than the worst conditions within the preserving environment permitted in public records management act. Also, the influence of the humidity on the preserving valuation index of a paper archives as decreasing the activation energy for the hydrolysis reaction was larger rather than temperature. Thus the preserving valuation index can easily evaluate the suitability of the temperature and humidity conditions for preserving a archives. Therefore it can be used as useful tool for preservation of archives on change of the temperature and humidity.

국내 울릉분지의 탄화수소 자원 탐사 및 지질구조 기초연구 등의 목적으로 일련의 탄성파 탐사가수행되었다. 성공적인 탄성파 해석을 위해 지하 구조를 정확하게 묘사하는 탄성파 단면이 필요하다. 울릉분지의기존 연구사례에서 소개된 탄성파 단면들은 영상화되는 영역이 천부에 국한된 경우가 다수이다. 본 연구에서는울릉분지의 지하구조를 5.0 s 하부까지 영상화하기 위하여 참 반사 보정을 수행하였다. 시간 영역 참 반사 보정을적용하여 부정합면을 포함하는 심부 지하구조의 연속성이 향상됨을 확인하였다. 참 반사 보정 결과 퇴적층서와기반암의 경계가 명확히 구분되었고 에돌이 잡음이 감소하였다. 겹쌓기-전 참 반사 보정단면은 반사 신호의진폭이 강조되어 음향 기반암 매질 특성을 반영하였다. 연구 결과 도출된 시간 영역 참 반사 보정 탄성파 단면은울릉분지 퇴적 발달양상을 연구하는데 도움이 될 것이다.

Seismic reflection surveys were conducted on the Ulleung Basin of East Sea, Korea to explore hydrocarbonand to gain insight into geological structure. More distinct and crisp reflection image is required for successfulinterpretation of subsurface structures. Many estabilished seismic sections of Ulleung Basin were confined to theimage of shallow subsurface. We tested migration parameters to produce seismic sections with an imaging depthto 5.0 s for Ulleung Basin. The result showed continuity enhancement of deep reflectors including unconformitylayer. Especially pre-stack time migration section clearly described the boundary between acoustic basement andbasin filling sediment. Diffraction noises on the stack section decreased after both post-stack and pre-stack migration. Amplitude of pre-stack migrated section emphasized the impedance change by strong reflection event at the acousticbasement. These time-migrated sections would be effectively used as tools for geological study explaining depositionalevolution of Ulleung Basin.