The pressure sensor had been widely used to effectively monitor the flow status of the water distribution system for ensuring the reliable water supply to urban residents for providing the prompt response to potential issues such as burst and leakage. This study aims to present a method for evaluating the performance of pressure sensors in an existing water distribution system using transient data from a field pipeline system. The water distribution system in Y District, D Metropolitan City, was selected for this research. The pressure data was collected using low-accuracy pressure sensors, capturing two types of data: daily data with 1Hz and high-frequency recording data (200 Hz) according to specific transient events. The analysis of these data was grounded in the information theory, introducing entropy as a measure of the information content within the signal. This method makes it possible to evaluate the performance of pressure sensors, including identifying the most sensitive point from daily data and determining the possible errors in data collected from designated pressure sensors.

한국전쟁은 서울을 폐허로 몰아넣는 파괴의 문(門)이 자 새로운 독립국가의 이상적 수도 서울을 다시 지어내 는 재탄생의 문이었다. 전후 30여 년간, 발전의 꿈과 의 욕에 부푼 계획가들은 저마다 새 서울의 골격을 구상하 고 만들어 나갔다. 이 연구는 ‘주체’와 ‘과정’에 주목하 여, 1950년대-1980년대 중반의 서울 도시계획과 개발 을 이상적 도시에 관한 상이한 목표와 방법을 추구했던 계획가들 간 충돌과 경쟁 과정이었음을 드러내고, 그들 간 힘겨루기 국면에 따라 도시계획과 개발 방향이 변화 를 거듭하며 전후 서울이 조성되었음을 그리고자 한다. 이 연구는 그동안 현대 도시계획사가 계획안이나 제 도, 도시 개발상 등의 ‘결과’를 중심으로 서술되면서, 서 울 도시개발이 특정한 방향으로 변화하거나 일관성을 갖지 못하는 흐름을 보였던 이유를 설명하지 못하고 있 음에 주목하였다. 이로부터 ‘도시계획가’라는 특정한 집 단의 관점과 기준에 의하여, 그들과 다른 생각을 지니 고 활약하였던 다른 계획가들이 소외되어 있으며, 시기 구분과 인식 또한 그들의 활동을 중심으로 정의되어 있 음을 발견하였다. 이에 따라 토목기술자와 건축가라는 계획가들과 그들의 구상을 발굴, 복원하고, 그들의 참여 에 의하여 수도재건 논의가 시작되었던 1952년부터 확 장된 서울시역과 한강의 개발이 마무리되는 1986년까 지의 기간을 전후 서울의 틀이 구상되고 완성되는 중요 한 시기로 파악하였다. 이 시기를 계획가들의 갈등과 조정 양상에 따라 크게 세 시기로 나누어, 각 시기별 도 시계획 논의와 실행 과정, 도시변화를 고찰한 연구 결 과를 정리하면 다음과 같다. 1952-65년은 관 주도로 도시계획이 마련된 시기로 서, 일제강점기 기술관료 출신 토목기술자들과 대한국 토계획학회 중심 도시계획가들이 기성 도시계획의 영향 하에서 분산 위주의 도시계획을 수립하였다. 최경렬 등 토목기술자들은 일제 하 도시계획을 이어 받아, 평면적 인 용도 구분과 체계적인 공지 확보를 통한 저밀도의 도심 경관을 추구하였다. 또한 동서방향 간선축 중심 도시 확장 방식에 따라 교외 주택지를 조성하여 인구를 분산하고자 하였으며 경인 간 연속적 도시 형성을 추구 하였다. 한편 주원을 비롯한 도시계획가들은 이를 극복 하고자 하면서, 경제지리학에 기반하여 국토의 균형 개 발을 추구하고 동심원형 도시 확장 방식을 통하여 교외 주택지를 조성하고자 하였다. 상이한 두 도시계획 논리 는 1960년대 중반, 동심원형 도시구조를 기초로 하면서 도 부분적으로는 간선축 중심의 선형 도시구조를 강조 하는 방향으로 절충되었다. 그러나 이러한 도시계획은 현실과의 괴리로 상당 부분 구상 차원에 머물렀다. 1966-74년은 도시계획이 관 외부 전문가들에 의하 여 제안되도록 민간 용역화하기 시작하면서, 기존의 계 획가 그룹에 더해 김수근 등을 중심으로 한 전후 해외 유학파 건축가와 그 유파, 외국인 도시계획 자문가 등 새로운 그룹이 등장하여 기성 도시계획을 비판, 변화시 켜 나간 역동적 시기였다. 이들은 물리적 환경의 조작 을 구체적으로 구상하는 ‘도시설계’에 의하여, 부분적 실행으로부터 도시를 바꾸어 나가고자 하였다. 그들은 슬럼화된 도로용지 위에 복합적 도시기능을 고밀도로 담는 ‘메가스트럭처’를 제안하면서 기성 도시계획 체계를 변형하고 주변부에 불과했던 도심 동부에 새로운 중 심을 형성하고자 하였다. 또한 선형 도시구조로의 전환 을 위한 인프라를 구상하여 도심을 관통하는 고가고속 도로 건설을 지원하였다. 그들은 교외에 주택지 건설 대신 직주근접의 고밀복합 ‘신도심’ 건설을 통하여 선형 도시구조로의 전환을 꾀하였으며, 이를 여의도 개발에 적용하였다. 1970년대 초, 국토종합개발계획 수립과 그 린벨트 설치로 도시계획가들의 동심원형 도시계획이 다 시 주도권을 가지면서 서울시는 영동 등지에 교외 주택 지 개발 중심의 신시가 건설을 전개하게 되었지만, 여 의도에서는 ‘고층 아파트 단지’라는 새 도심 주거 유형 이 출현하여 신도심화 지향이 여전히 지속되었다. 이 시기 건축가들의 새로운 시도를 통하여 서울의 경관과 구조는 실질적으로 변화하기 시작하였다. 1975-86년은 안보 위기에 대응한 도시개발 여건 제 한 속에서 상이한 구상을 지녔던 각 그룹의 입장이 조 정되고 서울 도시계획 방향이 전환되어 오늘날 서울 경 관과 구조의 틀이 형성되는 시기였다. 강북 인구 소산 책에 따라 단핵 동심원형 구조로부터의 탈피가 추구되 면서, 서울시는 해외 유학파 건축가 김형만이 새롭게 제시한 ‘3핵 도시’ 구상을 채택하게 된다. 그는 김수근 의 구상을 계승하면서 구도심, 영등포와 함께 영동의 도심화를 추진하였으며, 이에 따라 메가스트럭처, 고층 아파트 단지 등 신도심 조성을 위해 시도되었던 선례들 이 이식되어 직주근접의 고밀복합 도시를 신속하게 완 성하였다. 기성세대가 물러난 뒤, 최상철 등 새 인물들 이 중심이 된 도시계획가들은 기존 구상에서 구심성을 소거한 ‘다핵화’를 지향하면서, 해외 유학파 건축가들과 구상을 맞추어 가기 시작하였다. 그들은 동일한 자연 인식을 공유하면서 도시구조 재편의 일환으로 한강 정 비를 추진하였으며, 여기에 토목기술자들의 오랜 국토 개발 구상이 힘을 더하여 한강종합개발이 이루어지게 된다. 이로부터 서울은 구도심과 오랜 동서방향 간선축 에서 탈피하여 한강을 중심으로 세 도심이 배치된 도시 구조를 발전시켜 나가게 된다. 이상의 전후 서울의 탄생 과정은 다음과 같은 의미를 갖는다. 먼저, 이는 도시계획 주체를 민간화해 나가기 시작한 과정이었다. 관 주도의 일관된 질서에 의해 도 시가 조성되는 대신, 대규모로 확장된 도시의 각 부분 이 여러 주체들에 의해 다원적으로 구상되는 시대로의 전환이 이루어지고 있었다. 이는 전후 서울 도시계획의 일관성 부재를 설명하고 평가하는 중요한 지점이 될 것 이다. 다음으로 이는 전후 문화적 세대교체 속에서 시 차를 두고 도입된 국제적 도시계획 이론들이 제3세계 도시 서울이라는 문맥 속에서 만나 새로운 형태의 도시 구상을 낳는 과정이었다. 이로부터 대형복합시설, 고층 아파트 단지, 3도심 체제, 한강 중심 공간구조 등 오늘 날 서울을 특징짓는 경관과 도시 구조가 자리 잡기 시 작하였다. 한편 이는 상부의 철학, 원칙, 신념 등으로부 터 도시 형태를 만들어 나갈 것인지, 하부의 물리적 시 설 조성 기술로부터 도시 발전 방향을 결정해 나갈 것 인지, 규범과 경험 간 대결 속에서 도시계획 방법을 찾 아나가는 과정이기도 하였다. 이때 중요한 성취는 ‘도시 계획(urban planning)’ 뿐 아니라, 이에 대응하는 ‘도시 설계(urban design)’라는 건축가의 새 업역의 등장이었 다. 마지막으로, 이는 앞서 밝힌 변화들을 통해 도시계 획에 관한 오랜 관념을 딛고 기성 도시가 담지 못하는 전후의 새 정치·경제적 요구를 수용하여 도시의 체질을 근본적으로 전환해 나가는 과정이었다. 이와 같이 서울 도시계획이 다양한 입장을 지닌 여러 주체들에 의해 수립되었으며, 주체들 간 경쟁구도에서 비롯된 긴장을 내포하고 있음을 살핀 것은 의미 있는 작업이었다. 또한 이는 지금까지 서울 도시계획 주체로 서 제대로 다루어지지 못했던 건축가들의 구상을 고찰 하고, 전후 서울 경관과 구조 재편에 대한 그들의 기여 를 발굴하였다는 점에서도 중요하다. 그럼에도 이 연구 는 전후 서울의 탄생 과정의 다양한 장면들을 두루 살 피지 못하고, 도시 경관과 구조 재편의 시선에서 중요 한 사건들을 추려 한정적으로 살폈다는 점에서 빈틈을 갖고 있다. 앞으로 이 연구에서 다루지 못한 계획가들 과 그들의 구상, 실천을 살펴, 오늘날의 크고 복잡한 서울을 만들어 낸 힘들을 더욱 풍성하게 드러내게 되기를 기대한다.

This study aimed to investigate the relationship between the nutrition quotient and the dietary intake of adolescents. A total of 393 adolescents were surveyed to evaluate their Nutrition Quotient for Korean Adolescents (NQ-A) scores and dietary intake. The average age of the survey subjects was 15 years and the average NQ-A score of the subjects was 49.11±13.35. There was no significant difference in the NQ-A scores according to gender and age. The average dietary diversity score was 3.77±0.85, and it was significantly higher in boys than in girls (p< .05) with the scores of 12-14-year-old students being significantly higher than those aged 15-18 years (p< .01). The results of comparing the percentage of recommended intake or adequate intake and the mean adequacy ratio (MAR) according to the NQ-A grade, showed that the ‘High’ grade had a significantly higher intake percentage of vitamin B1, B12, folate, phosphorus, iron and a significantly higher MAR (p< .05). From a long-term perspective, efforts to improve dietary habits are deemed necessary to meet an individual’s nutritional requirements. Adolescents themselves should develop proper eating behaviors and acquire suitable dietary management skills to enhance their nutritional status, ultimately contributing to an improvement in their quality of life.

Risk assessment on Jeju Special Self-Governing Province(JSSGP)’s water supply facilities and establishment of adaptation measures for climate crisis factors were implemented. JSSGP’s vulnerability to the climate crisis was high in the order of drought, heat wave, heavy rain and strong wind. As a drought adaptation measure, policies of water saving and revenue water ratio improvement were considered. As for the heat wave adaptation measure, the introduction of an advanced water treatment process was suggested in response to the increase of algae cell number which resulting in taste and odor problem. As for heavy rain adaptation measures, the installation and operation of automatic coagulant injection devices for water purification plants that take turbid surface water were proposed. As a measure to adapt to strong winds, stabilization of power supply such as installation of dual power line was proposed in preparation for power outages. It is expected that water facilities will be able to supply high-quality tap water to customers even under extreme climate conditions without interruption through risk assessment for climate crisis factors and active implementation of adaptation measures.

본 연구의 목적은 독립 이후 보고타의 수도 위상에 대한 논쟁과 대립 이 19세기 각기 다른 정치 엘리트 그룹 간의 경쟁 구조와 어떤 상관성 을 가지고 있는지에 관해 분석하는 것이다. 콜롬비아의 경우, 독립 이 후 지역을 기반으로 각기 다른 엘리트 그룹의 정치·경제적 이해관계가 형성되는 독특한 정치 구조를 구축하였다. 이러한 엘리트 그룹 간의 정 치 경쟁 구조는 19세기 동안 아홉 차례의 무력 갈등을 발생시켰고, 이 과정에서 수도 보고타의 위상에 대한 논쟁을 유발하였다. 보고타를 중심 으로 한 전통적인 엘리트 세력이 보고타의 수도 위상을 유지하게 되면서 이를 공고히 하기 위한 전략으로 철도 건설 프로젝트를 통해 근대화 발 전을 시도했다. 본 연구는 수도 이전을 둘러싼 정치적 경쟁 구조 논의를 보고타의 사례로 분석했다는 점에서 의의를 가진다.

Numerous studies have established a correlation between sociodemographic characteristics and water usage, identifying population as a primary independent variable in mid- to long-term demand forecasting. Recent dramatic sociodemographic changes, including urban concentration-rural depopulation, low birth rates-aging population, and the rise in single-person households, are expected to impact water demand and supply patterns. This underscores the necessity for operational and managerial changes in existing water supply systems. While sociodemographic characteristics are regularly surveyed, the conducted surveys use aggregate units that do not align with the actual system. Consequently, many water demand forecasts have been conducted at the administrative district level without adequately considering the water supply system. This study presents an upward water demand forecasting model that accurately reflects real water facilities and consumers. The model comprises three key steps. Firstly, Statistics Korea’s SGIS (Statistical Geological Information System) data was reorganized at the DMA level. Secondly, DMAs were classified using the SOM (Self-Organizing Map) algorithm to consider differences in water facilities and consumer characteristics. Lastly, water demand forecasting employed the PCR (Principal Component Regression) method to address multicollinearity and overfitting issues. The performance evaluation of this model was conducted for DMAs classified as rural areas due to the insufficient number of DMAs. The estimation results indicate that the correlation coefficients exceeded 0.9, and the MAPE remained within approximately 10% for the test dataset. This method is expected to be useful for reorganization plans, such as the expansion and contraction of existing facilities.

As an advanced study on the method of calculating the target revenue water ratio of local waterworks through the leakage component analysis method proposed by Kim et al. (2022), this study developed a model to calculate the achievable revenue water ratio within the specified project cost, the required project cost to achieve the specified target revenue water ratio, and the economically appropriate target revenue water ratio level by considering the leakage reduction cost and leakage reduction benefit for each revenue water ratio improvement strategy, and conducted an applicability evaluation of the developed model using actual field data. The procedure for calculating the target revenue water ratio of local waterworks considering economics proposed in this study consists of three stages: physical data linkage model construction, leakage component analysis, and economic analysis, and the applicability was evaluated for Zone H with branch type and the Zone M network type. As a result of the application, it was calculated that approximately 32.5 billion won would be required to achieve the target revenue water ratio of 70% in the Zone H, and approximately KRW 10.5 billion would be required to achieve the target revenue water ratio of 75% in the Zone M. If the business scale of Zones H and M was corrected to 10,000 ㎥/day of water usage, the required project cost for a 1% improvement in the revenue water ratio of Zone H was calculated to be 0.7642 billion won and 0.4715 billion won for Zone M.

Passengers on public buses operating in the metropolitan area are exposed to the closed indoor air for minutes to hours. The indoor air quality of buses is mostly controlled through ceiling-mounted ventilation and filtration devices. A simulation study using a commercial code was conducted for fluid flow analysis to evaluate the potential effectiveness of an air purifier that can be inserted into bus windows to supply clean air from the outside to the inside. As a result of field measurements, the average CO2 concentration inside the bus during morning and evening rush hours ranged from 2,106±309 ppm to 3,308 ± 255 ppm depending on the number of passengers on board. This exceeded the Guideline for Public Transportation. The optimal installation position of an air purifier appeared to be the front side of the bus. In fact, even a low diffusing flow velocity of 0.5m/s was effective enough to maintain a low concentration of CO2 throughout the indoor space. Based on numerical analysis predictions with 45 passengers on board, the maximum CO2 concentration in the breathing zone was 2,203 ppm with the operation of an air purifier.

In light of recent social concerns related to issues such as water supply pipe deterioration leading to problems like leaks and degraded water quality, the significance of maintenance efforts to enhance water source quality and ensure a stable water supply has grown substantially. In this study, scan statistic was applied to analyze water quality complaints and water leakage accidents from 2015 to 2021 to present a reasonable method to identify areas requiring improvement in water management. SaTScan, a spatio-temporal statistical analysis program, and ArcGIS were used for spatial information analysis, and clusters with high relative risk (RR) were determined using the maximum log-likelihood ratio, relative risk, and Monte Carlo hypothesis test for I city, the target area. Specifically, in the case of water quality complaints, the analysis results were compared by distinguishing cases occurring before and after the onset of "red water." The period between 2015 and 2019 revealed that preceding the occurrence of red water, the leak cluster at location L2 posed a significantly higher risk (RR: 2.45) than other regions. As for water quality complaints, cluster C2 exhibited a notably elevated RR (RR: 2.21) and appeared concentrated in areas D and S, respectively. On the other hand, post-red water incidents of water quality complaints were predominantly concentrated in area S. The analysis found that the locations of complaint clusters were similar to those of red water incidents. Of these, cluster C7 exhibited a substantial RR of 4.58, signifying more than a twofold increase compared to pre-incident levels. A kernel density map analysis was performed using GIS to identify priority areas for waterworks management based on the central location of clusters and complaint cluster RR data.

In this study, non-destructive technologies that can be applied to evaluate the integrity of valve materials, safety against internal pressure caused by corrosion, and the blocking function of large-diameter water valves during operation without requiring specimen collection or manpower entering the inside of the valve were tested to assess the reliability of the technologies and their suitability for field application. The results showed that the condition of the graphite structure inside the valve body can be evaluated directly through the optical microscope in the field without specimen collection for large-diameter water butterfly valves, and the depth of corrosion inside the valve body can be determined by array ultrasound and the tensile strength can be measured by instrumented indentation test. The reliability of each of these non-destructive techniques is high, and they can be widely used to evaluate the condition of steel or cast iron pipes that are significantly smaller in thickness than valves. Evaluation of blocking function of the valves with mixed gas showed that it can be detected even when a very low flow rate of mixed gas passes through the disk along with the water flow. Finally, as a result of evaluating the field applicability of non-destructive technologies for three old butterfly valves installed in the US industrial water pipeline, it was found that it is possible to check the material and determine the suitability of large-diameter water valves without taking samples, and to determine the corrosion state and mechanical strength. In addition, it was possible to evaluate safety through the measurement results, and it is judged that the evaluation of the blocking function using mixed gas will help strengthen preventive response in the event of an accident.

In this study, the physical properties and fracture characteristics according to the tensile load are evaluated on the materials of the polymeric filler and carbon fiber-based composite sleeve technique. The polymeric filler and the composite sleeve technique are applied to areas where the pipe body thickness is reduced due to corrosion in large-diameter water pipes. First, the tensile strength of the polymeric filler was 161.48~240.43 kgf/cm2, and the tensile strength of the polyurea polymeric filler was relatively higher than that of the epoxy. However, the tensile strength of the polymeric filler is relatively very low compared to ductile cast iron pipes(4,300 kgf/cm2<) or steel pipes(4,100 kgf/cm2). Second, the tensile strength of glass fiber, which is mainly used in composite sleeves, is 3,887.0 kgf/cm2, and that of carbon fiber is up to 5,922.5 kgf/cm2. The tensile strengths of glass and carbon fiber are higher than ductile cast iron pipe or steel pipe. Third, when reinforcing the hemispherical simulated corrosion shape of the ductile cast iron pipe and the steel pipe with a polymeric filler, there was an effect of increasing the ultimate tensile load by 1.04 to 1.06 times, but the ultimate load was 37.7 to 53.7% compared to the ductile cast iron or steel specimen without corrosion damage. It was found that the effect on the reinforcement of the corrosion damaged part was insignificant. Fourth, the composite sleeve using carbon fiber showed an ultimate load of 1.10(0.61T, 1,821.0 kgf) and 1.02(0.60T, 2,290.7 kgf) times higher than the ductile cast iron pipe(1,657.83 kgf) and steel pipe(2,236.8 kgf), respectively. When using a composite sleeve such as fiber, the corrosion damage part of large-diameter water pipes can be reinforced with same level as the original pipe, and the supply stability can be secured through accident prevention.

This study aimed to investigate the need for dietary education and programs for young Koreans belonging to singleperson households in the metropolitan area. A total of 500 young adults aged 19-34 participated in the study through an online survey. Participants responded to questions on general characteristics, dietary problems, and the need for dietary education and programs. The subjects were divided into three groups as follows: Undergraduate students, employed workers, and others. Among the subjects from single-person households, 20.2, 67, and 12.8% were undergraduate students, employed workers, and others, respectively. When asked for their estimation of an appropriate self-pay when participating in a cooking class, 39.8% of total subjects responded ‘5,000-10,000 won’. The most preferred program for young adults in single-person households was the ‘support food package’. For the preferred method of dietary education, undergraduate students showed a greater preference for classes ‘at campuses’. However, employed workers and others had a higher preference for ‘non-face-to-face online classes’. Undergraduate students tended to generally have a higher preference for dietary education and support programs compared to employed workers and others. This study provides data that will be useful for establishing healthy dietary policies and education programs for young single-person households in Korea.

본 연구는 한국에서 예체능 계열 박사 과정에 재학 중인 중국인 유학생들의 교육 현황을 조사하고 분석하여, 한국 대학의 외국인 유학생 모집부터 교육에 이르기까지 합리적인 개선과 유용한 유학 정보를 제공하고자 한다. 본 연구의 목적을 달성하기 위해 다음과 같은 연구 절차를 거쳤다. 먼저, 한국 대학의 예체능 계열 박사 과정에 재학 중인 중국인 유학생들이 선호하는 사립 대학 상위 3곳을 선정하여 이들 대학의 학과, 전공 구분, 입학 요건, 지원 절차, 장학금 혜택 등의 내용을 분석하였다. 다음으로 인터뷰와 설문을 통해 예체능 계열 박사 과정 중국인 유학생들의 대학 선택 요인, 일상 및 학교생활 현황, 학습 상태, 학습 만족도, 한국어 능력 수준, 논문 진행 등의 교육 현황을 파악하였다. 이에 도출된 결과는 다음과 같다. 첫째, 학교 지원 절차, 중국인 유학생 수, 어학 성적 여부 그리고 지인과 유학 중개소의 추천을 대학 선택의 선결 조건으로 생각하기 때문에 대학교에서 유학생 모집 홍보, 한국과 중국 학교의 교류 프로그램 및 연합 과정 개설 등을 적극적으로 고려해야 한다. 둘째, 한국어 능력이 부족하여 일상, 학교생활에 불편한 데가 많다는 조사 결과에 따라 학교 측은 유학생들의 원활한 언어 소통에 관한 적극적인 지원과 도움이 필요하다고 판단된다. 셋째, 모든 교과목의 타당성과 전문성은 높은 반면, 실용성은 상대적으로 낮은 편이기 때문에 예체능 계열의 특수성을 고려한 맞춤형 한국어 연계 교과목의 개설이 매우 필요하다. 넷째, 논문의 진행에 있어 어느 정도의 한국어 실력을 갖추어야 하는 상황이므로 해당 학과에 속하거나 전문 용어를 통역할 수 있는 실력을 갖춘 통역자가 논문 통역을 담당해야 한다. 다섯째, 논문 작성 프로그램이나 사이버 시스템의 사용법을 가르치는 수업이 매우 필요하다. 이뿐만 아니라 유학생들이 희망하는 한·중 교류프로그램 등을 만들어 일상과 학교생활을 풍부하게 하고 불안감을 약화시킬 수 있다고 생각된다. 저자는 현재 한국 대학 외국인 박사 과정 모집에 있어, 언어 능력이 떨어지는 학생들을 선발하는 것이 본질적인 문제라고 생각한다. 그러나 각 대학의 운영 및 모집에 있어 실제적인 해결이 어렵다고 본다. 이를 본 연구의 한계점으로 보고, 가장 현실적인 상황을 고려하여 예체능 계열 중국인 유학생들의 교육 환경, 수업 설계, 학생 지원, 혜택 및 학습 방향과 관련된 근본적이고 구체적인 방안을 제공하였다. 본 연구가 한국의 고등 교육 기관의 외국인 유학생 모집 시스템 구축, 입시 그리고 유학생 교육, 지원 등 상황에 따른 교육 개선과 발전에 보다 유용한 자료로 활용되기를 바란다.

PURPOSES : The purpose of this study was to select recurring congested sections through an objective and reasonable method using intelligent transportation system (ITS) collection data as the first phase for controlling recurring congested sections. The selection is meant to enhance the utilization of national highway ITS collection data that are just managed as statistical data focusing on real-time traffic information or not satisfactorily used. METHODS : Hourly statistical data were obtained using travel speed with a 5-min frequency per information-providing section stored in the database server. The travel speed data were collected from field equipment in general national highway sections (793.8 km in 380 sections of 16 lines in 2017) in the Seoul Metropolitan Area through a literature review of congestion standards. Subsequently, the congested sections were drawn by dividing a month into weekdays and weekends, and the status of the monthly change and characteristics of the congested sections were analyzed. Based on the monthly data on the congested sections, monthly mean congested days and hours were calculated to select the significant recurring congested sections in 2017 and applied to the congestion frequency standard. RESULTS : Recurring congested sections occurred in seven sections (33.9 km) in three lines — in five sections (24.8 km) of two lines during the weekdays and in two sections (9.1 km) of one line during the weekends. The recurring congested sections selected based on the congested days and the recurring congested sections selected based on the congested hours were found to be the same. The recurring congested sections during the weekdays and weekends were not mutually duplicated and were divided. More congestion occurred during the weekdays than on weekends. CONCLUSIONS : In the seven sections selected as recurring congested sections, congestion occurred for more than six months during one year, indicating that congestion is concentrated in specific months, albeit continuously and repeatedly occurring over the long term. The recurring congestion section selection standard and method used in this study are considered to be objective and reasonable. If recurring congested sections are selected using the standard and method presented in this study using ITS collection data targeting general national highways nationwide in the Seoul Metropolitan Area, it is necessary to determine whether the standard and method reflect actual congestion situations satisfactorily. According to the result, a further study considering congestion speed and congestion frequency standards is needed.

In order to overcome the small scale of Korea waterworks and to achieve comprehensive improvement and innovation transformation, the waterworks integration was reviewed. The effect of consolidation was confirmed by the integration of the water supply business in the southern Gangwon region and the western Gyeongnam region in Korea, such as an increase in the flow rate and a decrease in the production unit cost. After facing management and service limitations overseas, more than 1,000 small-scale waterworks projects in the UK were integrated into 27 waterworks providers, and Japan also revised the Waterworks Act in December 2019 and is in the process of integrating waterworks. It is considered appropriate to promote the integration of waterworks projects in Korea by respecting the autonomy of local governments, but using a participatory method, a win-win method, and a linkage method. For the integration of waterworks projects, three strategies are proposed: First creating a national foundation for integration (revision of the Waterworks Act), Second establishing a waterworks integration strategy led by local governments, Third forming an external consensus and providing incentives for participation.

In this study, we collect water control valves that have had accidents due to existing cracks, etc. are collected, and propose investigation items for strengthening the valve structural safety evaluation through a series of analyzes from valve specifications to physicochemical properties are proposed. The results of this study are as follows. First, there was a large variation in the thickness of the body or flange of the valves to be investigated, which is considered to be very important factor, because it may affect the safety of the valve body against internal pressure and the flange connected with the bolt nut. Second, 60% of the valves under investigation had many voids in the valve body and flange, etc. and the decrease in thickness due to corrosion was relatively large on the inner surface in contact with water rather than the outer surface. It is judged that the investigation of depth included voids is very important factor. Third, all valves to be investigated are made of gray cast iron foam, and therefore it is judged that there is no major problem in chemical composition. It is judged that the chemical composition should be investigated. Fourth, as a physical investigation item, the analysis of metal morphology structure seems to be a very important factor for nodular cast iron from rather than a gray cast iron foam water valve with a flake structure. As it was found to be 46.7~68.8% of the standard recommended by KS, it could have a direct effect on damage such as cracks, and therefore it is judged that the evaluation of tensile strength is very important in evaluating the safety of the valve.

This study has been conducted to investigate the North Korea water supply system. For this purpose, laws and regulations concerning the North Korea water utilities were analyzed. According to this study, the water supply system of North Korea is similar to that of South Korea. The major difference between these two systems lies in the national water supplier: South Korea has the national water supplier as well as the municipal suppliers, while there is no national water supplier in North Korea. It is noted that the North Korean water utilities depend on outside suppliers for resources necessary for water production such as electricity, chemicals, spare parts, etc. This could damage the North Korean water utilities. If required resources were not delivered properly (deficient quantity and/or at delayed timing), the water suppliers would encounter difficulties in water production.