In recent years, solar cells based on crystalline silicon(c-Si) have accounted for much of the photovoltaic industry. The recent studies have focused on fabricating c-Si solar modules with low cost and improved efficiency. Among many suggested methods, a photovoltaic module with a shingled structure that is connected to a small cut cell in series is a recent strong candidate for low-cost, high efficiency energy harvesting systems. The shingled structure increases the efficiency compared to the module with 6 inch full cells by minimizing optical and electrical losses. In this study, we propoese a new Conductive Paste (CP) to interconnect cells in a shingled module and compare it with the Electrical Conductive Adhesives (ECA) in the conventional module. Since the CP consists of a compound of tin and bismuth, the module is more economical than the module with ECA, which contains silver. Moreover, the melting point of CP is below 150 ℃, so the cells can be integrated with decreased thermal-mechanical stress. The output of the shingled PV module connected by CP is the same as that of the module with ECA. In addition, electroluminescence (EL) analysis indicates that the introduction of CP does not provoke additional cracks. Furthermore, the CP soldering connects cells without increasing ohmic losses. Thus, this study confirms that interconnection with CP can integrate cells with reduced cost in shingled c-Si PV modules.

콘크리트사장교는 높은 자중에 비해 낮은 강성도를 가지더라도 저 형고의 단면으로 설계한다. 콘크리트사장교 케이블은 보강거더에 정착되는 케이블위치의 작은 변화에도 큰 장력변화를 나타낸다. 본 연구는 케이블 장력변화가 최소화할 수 있는 정착위치 결정이 목적이다. 이를 위하여 4개소의 보강거더 정착위치, 8개의 케이블 초기장력 및 90개의 시공단계에 대하여 구조거동을 분석하였다. 4개소의 케이블 정착위치를 분석한 결과, 정착위치가 도심하단으로 내려갈수록 케이블의 시공장력이 구조안정성을 좌우한다. 반대로 도심위에 정착장치를 설치할수록 케이블의 완성장력이 지배적이다. 결론적으로 정착위치가 보강거더 상단에 위치할수록 시공과 완성 케이블 장력편차가 다른 정착위치보다 가장 작게 발생하였다.

대의제는 익히 대화와 토론을 통한 공공의 이익 판단을 위하여 고안된 정치제도이다. 공공의 이익은 ‘결정’ 되거나 ‘발견’ 되어 진다. 결정되는 공익은 가치관의 차이에 의거 극단적인 대립 속에서 다수결의 원칙으로 정해지는 것이고 발견되는 공익은 숙의 없이 공익이 발견되는 경우와 숙의가 반드시 필요한 경우로 나뉜다. AI는 이 세 가지 유형 중에서 숙의가 필요한 경우에 가장 유용하게 사용될 수 있다. 현재에도 대의제의 핵심 요소인 선거를 통하여 선출된 대표자들이 공공의 이익을 판단을 돕기 위한 여러 가지 제도와 장치들이 구성되어 있다. 대통령의 직무를 돕기 위해 대통령의 인사권이 인정되는 ‘임명직’ 공직자나 국회의원의 공공의 이익 판단을 위해 국민 세금으로 운영되는 국회예산정책처, 국회입법조사처 등의 조사기관들이 그것이다. 이와 같이 최종 공익결정 권한이 없는 중간 판단자와 공익 결정의 권한이 있는 결정 주체 모두에게 AI는 유용할 수 있다. 물론, 대표를 선출하지 않는 (직접)민주주의 하에서도 AI는 기능할 수 있다. AI가 제공한 정보로 가부를 묻는 실시간 국민투표를 실시할 수 있는 기술의 발전을 기대할 수 있기 때문이다. 다만, 이와 같은 경우에는 가부를 묻는 의제의 선정을 사람이 아닌 AI가 맡기 때문에 실질적으로는 AI가 사람을 지배하는 상황으로 변질 될 수 있는 위험성도 매우 크다. 한 발 더 나아가 AI가 의제를 결정하고 중간 판단도 하며 최종 공익 결정도 AI가 할 경우 사람은 주권을 포기하거나 강탈당하거나 양자 중에 선택해야 한다. 물론 이와 같은 경우는 헌법적으로 용인되지 않는다. 그러나 이에 앞서 필수적으로 고려해야 하는 인공지능의 특징이 있다. 대부분의 사람들은 사람에 비하여 훨씬 AI가 ‘객관적’이라 믿는다. 하지만, AI는 어떤 알고리즘을 통하여 학습하는가에 따라서 완벽하게 다른 결론을 ‘객관적’으로 보이도록 할 수 있다. AI가 입법과정을 다룸에 있어서 사람만큼이나 편견이 생겨 그 편향성이 강화된다면 AI에게 객관성을 기대하기 어렵다. 편향성을 가진 인공지능이 의제를 결정하고 중간판단에도 개입하고 최종 공익 결정도 누군가에 의해 의도적인 알고리즘 조작을 통해 가능하다면 그것이 우리 인류가 대의제를 고안한 근본 원칙에 맞는 것인가에 대해 동의할 수 없음은 자명하다. 이것이 AI가 발전하면 서도 궁극적으로 공공의 이익의 최종 판단을 합의제 의사결정 기구인 국회에서 ‘사람’으로 구성된 국회의원이 해야만 하는 이유이다. 객관적일 것이라 기대하는 AI도 우리만큼 편향적일 수 있기에 우리가 마지막으로 기댈 수 있는 것은 ‘불완전한 인간’들의 숙의를 통한 공익 추구뿐이다.

분권과 자치의 역사는 권위주의 중앙집권 세력과의 민주주의 투쟁의 역사이다. 개헌에 대한 국민적 요구가 커지고 있는 시점에서 지방분권과 주민자 치를 위한 과제가 산적해있다. 따라서 분권과 자치는 저절로 주어지는 것이 아니라 기득권을 옹호하는 권위주의와 중앙집권 세력들로부터 전취해야 만 하는 것이다. 분권과 자치의 역사는 도입·중단·부활에 이어 발전기에 들었다. 그 이념도 민주에서 능률로, 능률에서 민주·능률·균형발전의 전반적(General) 발전기에 임박한 것이다. 1960년 4·19혁명이 이승만 정부의 권좌 유지 수단으로 전락한 지방자치법을 개정하여 민주적인 지방자치시대를 열었으나 5·16 군사쿠데타에 의해 무산되었고, 1987년 민주주의 6월 항쟁으로 지방자치 부활시대를 열었으나 개헌과정에서 주민의 참여가 배제되었고, 노태우정부의 지연과 교란을 딛고 우여곡절 속에 시행되었다. 이제 촛불혁명으로 ‘국정농 단’ 탄핵과 함께 지방분권 개헌의 시대를 맞이하고 있다. 곧 분권과 자치가 양적 확대의 단계에서 질적 비약의 단계로 발전할 것이다. 분권과 자치가 기득권과의 투쟁을 통해서 전취하는 것이라면 그것을 관철하기 위하여 전략적 이고 전술적인 방침이 중요하다. 분권 개헌을 전략적 최대강령으로, 지방의회의 인사권 독립을 전술적 최소 강령으로 삼을 것을 제안한다. 지방의회의 인사권 독립은 이미 정형화한 반대논리들의 예봉을 피하면서 막연하게 개헌 을 기다리지 말고 지방자치법 제91조 제2항을 합헌으로 결정한 헌재의 논리 적·역사적 모순을 비판함으로써 분권개헌이라는 전략적 목표로 접근할 수 있는 약한 고리이다. 무엇보다 본 논문은 분권과 자치, 그리고 분권개헌의 주체는 주민이라는 점을 강조하였다.

ECM 분석을 통해 카메룬 코코아 수출시 GDP와 비교우위가 주요 결정요인임이 밝혀졌다. 수출시장에서의 환율변동에 따른 코코아 수출가격의 변동은 국내 코코아 가격을 결정하는 주요인이다. 가격변동에 따라 수출되지 못하는 코코아의 국내 시장 공급은 과잉공급으로 연결되고 이는 국내시장가격의 현저한 하락을 초래한다.

Taguchi regarded the concept of quality as ‘total loss to society due to fluctuations in quality characteristics from the time of supplied to the customer.’ The loss function is a representative tool that can quantitatively convert the loss that occurs due to the deviation of the quality characteristic value from the target value. This has been utilized in various studies with the advantage that it can change the social loss caused by fluctuation of quality characteristics to economic cost. The loss function has also been used extensively in the study of producer specification limits. However, in previous studies, only the second order loss function of Taguchi is used. Therefore, various types of losses that can occur in the process can’t be considered. In this study, we divide the types of losses that can occur in the process considering the first and second loss functions and the Spiring’s reflected normal loss function, and perform total inspection before delivering the customer to determine the optimal producer specification limit that minimizes the total cost. Also, we will divide the quality policy for the products beyond the specification limits into two. In addition, we will show the illustration of expected loss cost change of each model according to the change of major condition such as customer specifications and maximum loss cost.

This study investigates the directional recrystallization behavior of Ni based oxide dispersion strengthened (ODS) alloy according to the zone annealing velocity. The zone annealing temperature is set as 1390oC, while the zone velocities are set as 2.5, 4, 6, and 10 cm/h, respectively. The initial microstructure observation of the as-extruded sample shows equiaxed grains of random orientation, with an average grain size of 530 nm. On the other hand, the zone annealed samples show a large deviation in grain size depending on the zone velocities. In particular, grains with a size of several millimeters are observed at 2.5-cm/h zone velocity. It is also found that the preferred orientation varies with the zone annealing velocity. On the basis of these results, this study discusses the role of zone velocities in the directional recrystallization of Ni base ODS alloy.

본 연구에서는 소비자의 식생활 라이프 스타일 유형에 따른 가축질병 인식(우려도)에 대한 결정요인을 분석하였다. 우선 식생활 라이프 스타일과 관련된 23개의 문항들을 이용하여 요인분석을 실시하고, 요인들의 평균값을 기준으로 군집분석을 실시하였다. 또한, 소비자들의 유형적 특성을 규명하기 위해, 인구 사회경제적 요인 및 식생활 관련 특성을 활용하여 교차분석 및 로짓분석을 실시하였다. 분석결과 가축질병이 국내에서 발생하거나 해외에서 감염 환자가 발생하는 등 사회적 이슈가 되었을 때, 소비자들의 불안감은 소비에 부정적으로 작용할 가능성이 높은 것으로 나타났다. 따라서 가축질병에 대한 소비자의 필요 이상의 불안감은 효율적으로 완화시킬 필요가 있으며 이를 위해 효율적인 리스크 커뮤니케이션을 전개가 필요한 것으로 판단된다.

PURPOSES : The objective of this study is to develop a pavement rehabilitation decision tree considering current pavement condition by evaluating severity and distress types such as roughness, cracking and rutting. METHODS: To improve the proposed overall rehabilitation decision tree, current decision tree from Korea and decision trees from other countries were summarized and investigated. The problem when applying the current rehabilitation method obtained from the decision tree applied in Seoul was further analyzed. It was found that the current decision trees do not consider different distress characteristics such as crack type, road types and functions. Because of this, different distress values for IRI, crack rate and plastic deformation was added to the proposed decision tree to properly recommend appropriate pavement rehabilitation. Utilizing the 2017 Seoul pavement management system data and considering all factors as discussed, the proposed overall decision tree was revised and improved. RESULTS: In this study, the type of crack was included to the decision tree. Meanwhile current design thickness and special asphalt mixture were studied and improved to be applied on different pavement condition. In addition, the improved decision tree was incorporated with the Seoul asphalt overlay design program. In the case of Seoul's rehabilitation budget, rehabilitation budget can be optimized if a 25mm milling and overlay thickness is used. CONCLUSIONS: A practical and theoretical evaluation tool in pavement rehabilitation design was presented and proposed for Seoul City.

This study investigated a bio-tensegrity structural system that combines the characteristics of a general tensegrity structural system with a biological system. The final research objective is to accomplish a changeability for the structural system as like the movement of the natural bio-system. In the study, we present a shape finding procedure for the two stage bio-tensegrity system model inspired by the movement pattern of animal backbone. The proposed system is allowing a dynamic movement by introducing the concept of “saddle” for the variable bio-tensegrity structure. Several shape finding analysis example and results are presented and shows a efficient validation and suitability.

As a system complexity increases and technology innovation progresses rapidly, leasing the equipment is considered as an important issue in many engineering areas. In practice, many engineering fields lease the equipment because it is an economical way to lease the equipment rather than to own the equipment. In addition, as the maintenance actions for the equipment are costly and need a specialist, the lessor is responsible for the maintenance actions in most leased contract. Hence, the lessor should establish the optimal maintenance strategy to minimize the maintenance cost. This paper proposes two periodic preventive maintenance policies for the leased equipment. The preventive maintenance action of policy 1 is performed with a periodic interval, in which their intervals are the same until the end of lease period. The other policy is to determine the periodic preventive maintenance interval minimizing total maintenance cost during the lease period. In addition, this paper presents two decision-making models to determine the preventive maintenance strategy for leased equipment based on the lessor’s preference between the maintenance cost and the reliability at the end of lease period. The structural properties of the proposed decision-making model are investigated and algorithms to search the optimal maintenance policy that are satisfied by the lessor are provided. A numerical example is provided to illustrate the proposed model. The results show that a maintenance policy minimizing the maintenance cost is selected as a reasonable decision as the lease term becomes shorter. Moreover, the frequent preventive maintenance actions are performed when the minimal repair cost is higher than the preventive maintenance cost, resulting in higher maintenance cost.

This study examined the risk components and risk types perceived in the context of purchasing decisions of paper fashion products. This study also identified the levels of perceived risk by consumers and the differences between age groups in risk perception. First, qualitative data were collected through a focus group interview with 7 Korean females in their 20s to 50s. The interviewees were presented with two types of paper materials (undyed and dyed Jumchi-Hanji) and products (bags and wallets) made with the papers. The interviewees mentioned 11 risk components which were classified into five types of risks: performance (easily torn/lack of durableness, lint/pilling/wear-out, lack of water-resistant, no washability, and deformation and discoloration over time), social-psychological (old and traditional image), aesthetic (lack of design diversity, unsatisfactory appearance due to repair), financial (expensive price, lack of usability in daily life) and time/convenience (difficulty in handling) risks. Based on the results of the interview, a measurement for evaluating the risk perception of paper fashion products was developed. Second, quantitative data were collected from 64 Korean women in their 20s to 50s using the measurement. Respondents who were presented with the paper materials and the products perceived the performance risk more strongly than the social-psychological risk and aesthetic risk. In addition, differences between age groups were found: younger respondents perceived performance risk and social-psychological risk more strongly than older respondents, but older respondents perceived financial risk more than younger respondents. Based on this study, strategies for the risk reduction of paper fashion products were proposed.

Recently, with the increase in demand for big data analysis, related techniques and tools are being developed, which makes it possible to utilize data that was difficult to analyze by traditional methods. Topic modeling is a useful technique for deriving topics from a vast amount of text, and is often used in research on trends and predictions of academic research or science and technology. However, the topic derived from the topic modeling is a combination of words presented on the basis of the frequency and probability of simultaneous occurrence, and cannot describe the importance or priority of each word. Therefore, in this study, we applied AHP (Analytic Hierarchy Process) technique to evaluate the priority of the result derived from topic modeling (Topic). In this study, bibliographic data (total of 15,888 articles) of academic researches related to consulting were collected and used in the analysis of this study in order to suggest prioritization method using Topic-Modeling and AHP.

This study explores determinants of purchase intentions for vegan fashion products based on the modified planned behavior model. Survey data from 434 university students were subjected to an analysis using descriptive statistics, factor analysis, and structural equation modeling. The results showed that almost half of the consumers surveyed recognized vegan fashion products and a little more than a half of consumers surveyed had purchase experience for vegan fashion products. Clothing, bags, and shoes are the most frequently purchased vegan fashion product categories. From the results of the model test, purchase intentions on vegan fashion products were determined by attitude, subjective norms, ethical responsibility, and ethical identity of the consumers. When consumers have a more positive attitude, have higher subjective norms, stronger ethical responsibility, and stronger ethical identity regarding the purchase of vegan fashion products, they are likely to have a greater intention to purchase vegan fashion products. The findings contribute to the literature by adding test results for vegan fashion products among the ethical product categories, highlighting the importance of the consideration of product category, which can give somewhat different results when exploring ethical consumption. Based on these findings, marketers need to use special tags or signage highlighting the ethical values and meanings of vegan fashion products to better communicate with target consumers with a high level of ethical responsibility and to help increase consumers’ control over purchase behaviors through reducing barriers generated by insufficient product information.

This study was carried out to investigate the effect of grain size on the damping capacity of the Fe-26Mn-4Co-2Al damping alloy. α’ and ε-martensite were formed by cold working, and these martensites were formed with a specific direction and surface relief. With an increase in grain size, the volume fraction of α’ and ε-martensite increased by decrement the austenite phase stability. This volume fraction more rapidly increased in cold-rolled specimen than in the specimen that was not cold-rolled. The damping capacity also increased more with the augmentation an increased grain size and more rapidly increased in cold-rolled specimen than in the specimen that was not cold rolled. The effect of grain size on the damping capacity was larger in the cold-rolled specimen than the specimen that was not cold-rolled. Damping capacity linearly increased with an increase in volume fraction of ε-martensite. Thus, the damping capacity was affected by the ε-martensite.

본 연구는 국제사회의 대북제재가 왜 큰 효과를 나타내지 못했는가에 대한 문제인식에서 출발하고 있으며, 이러한 질문의 답을 찾기 위해 중국의 대북지원에 주목하고서 대북지원의 결정요인을 분석한다. 국제사회의 강경한 대북제재에도 불구하고 중국은 북한에 대해 제재와 지원이라는 이중적 자세를 취하고 있다. 이러한 중국의 이중적 자세에 대해 본 연구는 양면게임이론에 이론적 근거를 두고서 대북지원이 대한 대내외적 상황에 접근하였다. 중국의 대북지원에 대한 결정요인은 국외요인, 국내요인으로 구분할 수 있다. 이들 요인들은 중국의 패권강화, 미국 견제, 중국의 책임 있는 강대국 역할 수행, 북한의 자원 확보, 중국의 안정적인 성장 지속, 중국의 사회주의정치체제 정당성 유지, 베이징 컨센서스의 확산 등이 있다. 해당 요인들에 대한 분석을 토대로 살펴보면 향후 중국의 대북지원은 공식적 또는 비공식적 모두 지속적으로 이루어질 것이고 대북지원이 중단 되거나 북·중 관계가 악화되는 상황이 발생하는 것은 어려울 것이라고 전망할 수 있다.

Machines and facilities are physically or chemically degenerated by continuous usage. One of the results of this degeneration is the process mean shift. By the result of degeneration, non-conforming products and malfunction of machine occur. Therefore a periodic preventive resetting the process is necessary. This type of preventive action is called ‘preventive maintenance policy.’ Preventive maintenance presupposes that the preventive (resetting the process) cost is smaller than the cost of failure caused by the malfunction of machine. The process mean shift problem is a field of preventive maintenance. This field deals the interrelationship between the quality cost and the process resetting cost before machine breaks down. Quality cost is the sum of the non-conforming item cost and quality loss cost. Quality loss cost is due to the deviation between the quality characteristics from the target value. Under the process mean shift, the quality cost is increasing continuously whereas the process resetting cost is constant value. The objective function is total costs per unit wear, the decision variables are the wear limit (resetting period) and the initial process mean. Comparing the previous studies, we set the process variance as an increasing concave function and set the quality loss function as Cpm+ simultaneously. In the Cpm+, loss function has different cost coefficients according to the direction of the quality characteristics from target value. A numerical example is presented.