PURPOSES : High concentrations of particulate matter (PM) are emitted or generated from vehicle emissions in urban roads with dense transient populations. To reduce the effect of PM emission on bus stop users at roadsides, a plan to reduce PM emitted from the roadside must be devised. In this study, an atmospheric environment at a roadside is simulated in a large-scale environment chamber, and a test for reducing PM around the bus stop is conducted by installing a bus stop adapted to a PM reduction system. METHODS : Exhaust gas is injected into the experimental and reference chambers using diesel and gasoline vehicles for roadside airquality simulations. The two vehicles are operated in an idle state without an acceleration operation to emit exhaust gas uniformly, and the initial conditions are achieved by injecting car emissions for approximately 40 min. The initial condition is set to 1 ppm of NOx concentration in the environment chamber. Between the two environment chambers, a bus stop adapted to the PM reduction system is installed in the experimental chamber to conduct a PM reduction experiment pertaining to the air quality around the roadside. The experimental progress is set as the start time of the experiment based on the time at which the initial conditions are achieved; simultaneously, the PM reduction system in the experimental chamber is operated. After the simulation is commenced, the PM concentration, which changes over time, is measured using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) without additional injection of car emissions or pollutants. The HR-ToF-AMS measures the chemical composition of non-refractory PM1.0 (NR-PM1.0) in real time. RESULTS : The NR-PM1.0 compound (organic aerosol (OA), NO3 -, SO4 2-) increases by 160% compared with the simulated initial concentration up to T90min in both environmental chambers; this is speculated to be due to secondary formation. The reference chamber indicates a slight decrease or a steady-state after T90min, whereas the experimental chamber indicates a gradually decrease as the experiment progresses. The bus stop adapted to the PM reduction system reduces the amount of black carbon in the experimental chamber by 37% at 200 min. This implies that the PM emitted from the roadside is filtered via the PM reduction system installed at the bus stop, and cleaner air quality can be provided to passengers. CONCLUSIONS : The PM reduction system evaluated in this study can be detached from and attached to the outdoor billboard of a bus stop. Since it adopts air filtration technology that uses a high-efficiency particulate air filter, it can be maintained and managed easily. In addition, it can provide an atmospheric environment with reduced PM emission to passengers as well as provide a better air-quality condition to passengers waiting for public transportation near roadsides.

본 연구는 조직 내 부정적 리더십의 한 형태로 관심을 받고 있는 상사의 비인격적 행동이 구성원의 과업성과에 미치는 과정을 살펴보았다. 상사의 비인격적 행동이 과업성과에 미치는 과정에서 매개변수로써 구성원이 인식한 상사에 대한 호감(이하 리더호감)과 조절변수로서 구성원의 내적 특성인 친교 욕구를 살펴보았다. 변수 간 관계를 검증하기 위하여 설문 조사를 통하여 변수들을 측정하였으며, 다양한 조직이나 회사에 근무하고 있는 구성원을 대상으로 구글(google) 설문지로 작성하여 페이스북을 통해 배포 및 173부를 회수하였다. 실증연구 결과 상사의 비인격적 행동과 구성원의 과업성과 간의 관계에서 리더 호감의 매개효과가 검증되었다. 상사의 비인격적인 행동이 높을수록 리더호감은 감소하였고, 그 결과 과업성과에 부정적인 영향을 미치는 것으로 나타났다. 그리고 구성원의 친교욕구는 상사의 비인격적 행동, 리더 호감, 과업성과 간의 관계에서 조절된 매개효과가 검증되었다. 즉, 친교욕구가 높은 구성원은 낮은 구성원 보다 상사의 비인격적인 행동에 따른 리더호감이 더 강하게 감소하였고, 과업성과에도 더 강한 부정적인 영향을 미치는 것으로 나타났다. 연구결과에 따른 시사점과 연구 한계점 및 향후 연구방향을 제시하였다.

4차 산업시대를 맞이하여 많은 공학 분야에서 IoT(Internet of Things)기술의 연계는 매우 중요한 쟁점이다. 최근 조선소에서도 디지털 조선, 스마트 팩토리 등의 개념을 구체화하고 있는 추세이다. 한편 자동차, 비행기 등에서 자율주행을 구현하는 연구는 매우 활발 하고 일정 부분 상용의 형태로 나타나고 있다. 본 연구는 오픈 소스 아두파일럿 기반의 FC(Flight Controller) 및 RTK(Real Time Kinematic) GPS(Global Positioning System)를 이용하여 자율 주행 임무를 수행하는 보트의 주행성에 관한 연구로서 잔잔한 호수에서 실해역 실험을 수행하였으며 보트의 임무는 특정한 지점을 자율주행한 후 홈 위치로 스스로 돌아오는 과정에 대한 조종성 평가이다. 주어진 속도에서 기 설정된 임무 궤적과 실 운항 궤적에 따른 차이를 분석하고 시스템의 보트 적용성에 대한 일련의 연구를 수행하였다. 또한 4개의 프로펠러를 가지는 OmniX 선체의 주행성을 분석하였으며 최대 48%의 주행 추적성 향상을 확인하였다.

As the frequency of seismic disasters in Korea has increased rapidly since 2016, interest in systematic maintenance and crisis response technologies for structures has been increasing. A data-based leading management system of Lifeline facilities is important for rapid disaster response. In particular, the water supply network, one of the major Lifeline facilities, must be operated by a systematic maintenance and emergency response system for stable water supply. As one of the methods for this, the importance of the structural health monitoring(SHM) technology has emerged as the recent continuous development of sensor and signal processing technology. Among the various types of SHM, because all machines generate vibration, research and application on the efficiency of a vibration-based SHM are expanding. This paper reviews a vibration-based pipeline SHM system for seismic disaster response of water supply pipelines including types of vibration sensors, the current status of vibration signal processing technology and domestic major research on structural pipeline health monitoring, additionally with application plan for existing pipeline operation system.

PURPOSES : In this study, we analyzed the characteristics of nitrogen oxide and fine particulate matter concentration for boarding positions at the bus stop of an exclusive bus lane, using a correlation analysis and a generalized linear model. METHODS : To analyze the air pollution characteristics for boarding positions at the bus stop, data on nitrogen oxide, fine particulate matter concentration, relative humidity, temperature, wind speed, solar radiation, and bus traffic volume were acquired. Using the collected data, a correlation analysis for nitrogen oxide and fine particulate matter was carried out for each boarding position. Additionally, the prediction models for each pollutant were estimated using a generalized linear model, to analyze their characteristics. RESULTS : Correlation analysis revealed that relative humidity and bus volume were positively correlated with both nitrogen oxide and fine particulate matter concentrations in all boarding positions, whereas temperature, wind speed, and solar radiation were negatively correlated. Based on the estimated models from the generalized linear model, the nitrogen oxide concentration at the first measurement point was found to be affected by relative humidity, temperature, and bus volume, whereas at the second measurement point, it was found to be affected by relative humidity, temperature, and solar radiation. Additionally, all factors were significant for fine particulate matter concentration at both boarding positions. CONCLUSIONS : The analytical results indicated that the characteristics of nitrogen oxide and fine particulate matter concentration at the bus stop of an exclusive bus lane varied significantly depending on the boarding positions. Particularly, it was found that the correlation between solar radiation, and nitrogen oxide and fine particulate matter was different because of the conversion of nitrogen oxide to fine particulate matter.

The number of vegans has increased rapidly due to religious and ethical beliefs, environmental concerns, health, etc. Also, as interest in healthy and safe food increases, the demand for organic products or nutrition-enhanced products is increasing. Therefore, this study aimed to investigate the selection attributes and purchasing behavior for protein-fortified and vegan snacks. It is anticipated that the results would find use as basic data for developing protein-fortified snacks for vegans that can meet consumer needs and derive marketing strategies. A survey was conducted on 140 consumers. According to the analysis of their purchase behavior, the number of people who had purchased high-protein snacks and vegan snacks was higher than those who did not have prior experience. The reasons for the purchase of protein fortified snacks included ‘meal replacement’ at ‘offline-convenient store/supermarket’. Vegan snacks were purchased for ‘ethical beliefs, health, environment’ at ‘offline-vegan restaurant, bakery’. Both snacks showed above-normal preferences. However, it is necessary to improve taste and flavor when developing these products as these were the factors that negatively impacted the preferences. The attributes were factorized into the ‘showing off factor’, ‘sensory factor’, ‘credence factor’, and ‘functional factor’ and the ‘sensory factor’ was considered the most important.

PURPOSES : The objective of this study is to analyze the uniform diffusion mechanism of precursor gas species, and the effect of NOx reduction technology in a full-scale particulate matter testing facility, using computational fluid dynamics (CFD). METHODS : A full-scale environment chamber was constructed to evaluate the effects of particulate matter reduction technologies on the road. CFD analysis was conducted to simulate the road environment conditions in the chamber, and investigate the effect of the NOx removal panel. The time required to reach the NOx concentration to target value in the fluid field was determined at a given inflow velocity, inlet direction, and initial inflow concentration. The effect of the NOx removal panel, and solar energy on the reduction characteristics of the NOx concentration in the environment chamber was analyzed. RESULTS : The inflow velocity was determined to be the major factor affecting the time required to reach a uniform target NOx concentration in the environment chamber. The inlet location in the transverse direction requires additional time to approach the uniform target concentration, than the longitudinal direction at the same inflow velocity. Based on the CFD analysis in the 1ppm concentration condition of the chamber, a two-fold increase in the NOx removal panel efficiency can reduce the time to target concentration by approximately 50%. It is also observed that a 20% increase in solar energy can decrease the time to target concentration by 4%–12% depending on the panel efficiency. CONCLUSIONS : This study proved that a full-scale environment chamber can be effectively utilized to evaluate the particulate matter reduction technologies applied in road facilities

본 연구의 목적은 신체 전신 운동인 맵시 운동 프로그램을 중년여성들에게 8주간 적용하여 보행 시 수직 지면반력 크기, 발생시간, 압력 중심 요인들에 미치는 영향을 분석하는데 있었다. 본 연구의 피험자로 운동군 13명(연령, 41±4.4 세; 신장, 162.5±5.8 cm; 체중, 57.8±6.7 kg; 신체질량지수, 21.9±2.4 kg/m2), 대조군 12명(연령, 41.1±5.6 세; 신장, 160.9±5.5 cm; 체중, 576.2±8.1 kg; 신체질량 지수, 21.7±2.9 kg/m2) 총 25명이 참여하였다. 운동군은 7영역 23종 77동작의 맵시운동 프로그램을 8주간 주 3회 실시하였다. 보행 시 지면반력 요인들의 검증을 위하여 Two-way repeated measures ANOVA 를 실시하였으며, 사후검증은 bonferroni adjustment로 분석하였다(a=.05). 맵시 운동 프로그램의 운동군은 보행 시 FMWA와 FPO 시점까지의 소요 시간, FMWA와 FPO에서 발생한 수직 지면반발력 그리고 AP 방향 COP의 RMS 요인들에서 대조군에 비해 상대적으로 큰 수치를 나타내었다. 그러므로 8주간의 맵시 운동 프로그램은 보행을 수행하는 중년여성들의 가속과 감속 운동 기능을 향상시킨 것으로 나타났다.

PURPOSES : The purpose of this study was to analyze the effect of reducing nitrogen oxide concentration in a photocatalyst (titanium dioxide) using statistical methods such as the Anderson-Darling test. METHODS : To compare and analyze the effect of reducing the nitrogen oxide concentrations in titanium dioxide, titanium dioxide was applied to the public road, and data acquisition in terms of nitrogen oxide concentration was conducted from roads with/without applying titanium dioxide (test section and reference section, respectively). Then, the probabilities of occurrence of nitrogen oxide concentrations in the test and reference sections were estimated and compared using the Anderson-Darling test. RESULTS : According to the comparison and analysis of probabilities in the nitrogen oxide concentration of the test and reference sections, the probabilities of nitrogen oxide concentration on December 4th were estimated as ‘High’ (17.5%, 37.9%), ‘Moderate’ (30.5%, 40.8%), and ‘Low’ (52.0%, 21.3%), respectively, and on December 5th, as ‘High’ (20.6%, 39.1%), ‘Moderate’ (26.2%, 33.0%), and ‘Low’ (53.2%, 27.9%), respectively. In addition, the probabilities of nitrogen oxide concentration in the test and reference sections were analyzed on December 6th as ‘High’ (16.5%, 36.8%), ‘Moderate’ (27.9%, 38.5%), and ‘Low’ (55.6%, 24.8%), respectively. CONCLUSIONS : Based on the results of this study, in the test section with application of titanium dioxide, the nitrogen oxide concentration was found to have a low probability, and in the reference section, the nitrogen oxide concentration was found to be higher than that in the test section. Therefore, it can be concluded that titanium dioxide applied to road facilities has a nitrogen oxide reduction effect.

The purpose of this study was to investigate the sensory properties and consumer preference of Korean menu for different cooking water. Mineral water (MW) and bottled water (BW) were used as cooking water. Sensory attributes were derived by qualitative evaluation, and preference tests were conducted using the duo-trio test and 9 point likert scale. Mechanic properties were also evaluated. For the sensory attribute, properties such as tough, greasy, glossy, salty were derived when cooked with MW. For consumer preference, overall taste, aftertaste, and degree of sticky of bap were significantly higher in MW than in BW (p<0.05). The preference for the rich flavor of sagol broth (p<0.05) was significantly higher in MW than in BW. Preference for taste and flavor of omija-hwachae was higher than BW (p<0.01). In the mechanical properties test, food material boiled with MW showed higher property for cohesiveness and gumminess (p<0.05). In conclusion, cooking water with high calcium and magnesium content has been evaluated to enhance the palatability of Korean menus such as bap and sagol broth, and thus it is considered that various Korean menus can be applied. This suggests that dietary calcium and magnesium intake can be increased by using cooking water with a high calcium and magnesium content.

PURPOSES : This study analyzes the service life of the repair methods of jointed plain concrete pavement (JPCP) on expressways in Korea using PMS data. METHODS : The Korea Expressway Corporation PMS data acquired from five major expressways in Korea were used for the analysis. The service lives of the repair methods were considered for two different cases: 1) the previous repair methods had been completely rerepaired by another or the same method due to their damage, and 2) the current repair methods were still in use. RESULTS : The service lives of D/G and section repair were shown to be at least 30 % and 50 % shorter than expected, respectively. Joint sealing and crack sealing exhibited a service life similar to that expected. The Mill-and-Asphalt-overlay method showed an approximately 30 % longer service life; this might be because some damage to the asphalt overlay is typically neglected until subsequent maintenance and repair. When multiple repairs were applied in series for an identical pavement section, the service life of repairs on previously damaged secti ons become even shorter compared to their first application. CONCLUSIONS : It was found that the analyzed service life of most important repair methods did not reach the expected service life, and that the service life of the same repair method becomes shorter as applied to the previously repaired concrete pavement sections. These shorter service lives should be seriously considered in future JPCP repair strategy development.

급냉법에 의한 역 열유도상전이(RTIPS) 공정을 사용하여 mesoporous polystyrene (PS), polyethersulfone (PES) 막 을 제조하였다. 급냉법에 의한 RTIPS 공정은 급냉 및 승온 시 도포 용액 내 용매 분자들의 결정 생성 및 성장을 통해 나노 규 모의 상전이를 야기시켜 mesoporous 기공들을 형성된다. 시차주사열량계(TA: DSC) 사용해 측정된 사용 용매 dimethylformamide (DMF)와 여러 고분자 함량의 고분자용액들에 대한 엔탈피 변화와 주사현미경(SEM)을 사용하여 측정한 고분자함량에 따른 제조된 막 구조, 그리고 비표면적 분석기(BET) 사용하여 측정한 고분자 함량에 따라 제조된 막의 기공크기분포 및 표준편 차 분석을 통해 RTIPS 공정 시 상전이 거동을 살펴보았다.

PURPOSES : This study analyzes the characteristics of nitrogen oxide concentration by applying titanium dioxide to existing roads in urban areas, using correlation analysis and a generalized linear model. METHODS : To analyze the characteristics of nitrogen oxide concentration with/without applying titanium dioxide to the urban road segment, data acquisition was conducted for nitrogen oxide concentration, weather information, and traffic information, etc., and a correlation analysis was conducted for each factor, with/without applying titanium dioxide to the roads. In addition, nitrogen oxide concentration generation models with/without the application of titanium dioxide to the roads were estimated using a generalized linear model. RESULTS : The results demonstrate that relative humidity and temperature were found to be slightly correlated with the nitrogen oxide concentration, both with and without the application of titanium dioxide to the roads; however, wind speed, solar radiation, and traffic volume were found to have somewhat low correlation according to the results of a correlation analysis. Moreover, relative humidity, temperature, solar radiation, and traffic volume were significant when titanium dioxide was applied to the roads, based on the estimated model from a generalized linear model, and the wind speed, solar radiation, and traffic volume were significant for the absence of titanium dioxide on the roads. CONCLUSIONS : Analytical results indicated that the characteristics of nitrogen oxide concentration vary depending on the application of titanium dioxide to the roads. In particular, when titanium dioxide was applied to the roads, the relative humidity and temperature were analyzed; according to both analyses, i.e., correlation analysis and a generalized linear model, the nitrogen oxide concentration was affected.

본 논문은 콘크리트 구조물 보강공법 중 하나인 CFRP 표면매립 긴장보강의 거동을 분석하였다. 이를 위해 CFRP 긴장재 및 긴장시스템을 개발하고 손상후 보강거동 및 충전재 유무에 따른 비부착 보강거동을 고찰하였다. 실험결과, 비부착 실험 체의 보강효과는 무보강 실험체보다 38% 증가하지만, 부착 실험체보다 17% 감소하였다. 손상된 콘크리트를 보강한 경우는 건전한 콘크리트의 보강효과와 유사했다. 정착장치와 부착된 CFRP 긴장재는 안정된 보강효과를 보였다.

국제적인 경쟁의 심화, 환경적 불확실성의 고조 등은 조직의 생존과 번영을 위한 더욱 많은 고민과 노력을 필요로 한다. 특히 조직 성과 및 성공의 기초가 되는 구성원의 행동과 성과의 중요성이 더욱 부각되면서 이들을 동기부여하기 위해 다양한 조직관리 방식, 인적자원관리 제도 등이 소개 및 도입되고 있다. 그 중에서도 조직에 대한 구성원의 책임감과 소속감을 유지시키고, 기본 임무 완수 및 창의적 업무 성과를 창출해 낼 수 있도록 하는 리더의 능력과 자질이 더욱 요구되는 시점이다. 하지만 실제 조직에서는 바람직한 리더십 못지 않게, 상사의 강압적이고 비윤리적인 행동 또한 실존하며 이런 부정적 리더십에 의해 비용은 결코 적지 않다. 아울러 리더의 파괴적인 영향력은 개인뿐만 아니라 조직 전체의 효율성 저하 및 조직문화의 파괴로 이어지고, 나아가 사회 및 국가 경쟁력 저하의 원인이 되기도 한다. 본 연구에서는 조직 구성원의 과업성과와 조직 경쟁우위의 원천으로 인식되는 창의성을 저해하는 위계상 상급자인 상사의 파괴적이고 비윤리적인 전제적 리더십의 부정적 영향과 이 과정에서의 심리적 주인의식의 매개 효과에 관한 실증 연구를 수행하였다. 육군 간부(장교 및 부사관)를 대상으로 부하와 그들의 직속상사로 구성된 총 211쌍의 설문자료를 분석한 결과, 상사의 전제적 리더십은 구성원들의 심리적 주인의식과 부적(-) 관계를 가지는 것으로 나타났고, 낮아진 심리적 주인의식이 전제적 리더십이 과업성과와 창의성에 미치는 부정적 효과를 매개하는 것으로 확인되었다. 본 연구 결과는 전제적 리더가 조직 구성원의 심리적 주인의식을 저해하는 파괴적 요인이며, 이와 함께 심리적 주인의식이 구성원들의 과업성과 및 창의성을 저하시키는 전제적 리더십 행동의 파괴성을 연결하는 중요한 역할을 하고 있음을 시사한다. 본 연구는 실증연구를 통해 상대적으로 연구가 제한된 전제적 리더십의 부정적 효과에 대한 이해의 범위를 넓히고, 리더의 긍정적 리더십이 주류를 이루는 전통적인 리더십 연구와는 다른 관점을 택함으로써 리더십 연구의 영역을 확장하였다. 또한, 전제적 리더십이 부하의 심리적 주인의식에 어떤 영향을 미치는지, 그 영향으로 인해 과업성과 및 부하의 창의성은 어떻게 달라지는지를 살펴봄으로써 실무적으로도 현장에서 억제 또는 제거되어야 할 부정적 리더십에 대한 구체적인 교훈을 제공한다. 이를 통해 생존과 번영을 추구하는 조직 경영자들에게 현장의 리더십을 어떻게 관리하고 무엇을 교육·훈련시켜야 할 것인가에 대한 시사점을 제안하고 있다. 마지막으로 연구의 한계점 및 향후 연구 방향이 논의되었다.