「장애인복지법」에 따라 국가 자격시험은 장애인과 비장애인이 동일한 시험에 응시할 수 있도록 하고 있으며, 청각장애는 동 력수상레저기구 면허취득 결격사유에 해당하지 않아 청각장애인도 면허취득을 할 수 있다. 선박이나 동력수상레저기구에서는 해상에서 충돌위험이 있을 때 조종신호, 경고신호 등의 위험신호를 음향신호를 통해 상대에게 알려 주위의 위험 상황을 발견하지 못하여 발생할 수 있는 사고를 예방하도록 하고 있다. 하지만, 청각장애인의 레저활동 중 주위 선박이나 동력수상레저기구의 소리를 통한 위험신호를 청 각장애로 인해 위험신호를 확인하지 못해 발생할 수 있는 해양사고를 방지할 수 있는 방안이 필요하다. 음향수신장치(Sound Reception System)는 선교가 완전히 폐위된 선박에 설치하여 외부 소리의 증폭과 소리의 수신 방향을 화면상에 표시하는 장치로서, 청각장애인의 동 력수상레저기구에 선박 음향수신장치를 활용하여 청각장애로 인해 청취할 수 없는 위험신호와 같은 음향신호의 유무 및 방향을 동력수 상레저기구의 화면상에 시각적 표시를 통해, 청각장애인의 레저활동 중 음향신호를 확인하지 못하여 발생할 수 있는 해양사고를 예방하 기 위한 개선방안을 제시하였다.

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.

Organoleptic parameters such as color, odor, and flavor influence consumer perception of drinking water quality. This study aims to evaluate the taste of the selected bottled and tap water samples using an electronic tongue (E-tongue) instead of a sensory test. Bottled and tap water's mineral components are related to the overall preference for water taste. Contrary to the sensory test, the potentiometric E-tongue method presented in this study distinguishes taste by measuring the mineral components in water, and the data obtained can be statistically analyzed. Eleven bottled water products from various brands and one tap water from I city in Korea were evaluated. The E-tongue data were statistically analyzed using multivariate statistical tools such as hierarchical clustering analysis (HCA), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the E-tongue method can clearly distinguish taste discrimination in drinking water differing in water quality based on the ion-related water quality parameters. The water quality parameters that affect taste discrimination were found to be total dissolved solids (TDS), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), sulfate (SO4 2-), chloride (Cl-), potassium (K+) and pH. The distance calculation of HCA was used to quantify the differences between 12 different types of drinking water. The proposed E-tongue method is a practical tool to quantitatively evaluate the differences between samples in water quality items related to the ionic components. It can be helpful in quality control of drinking water.

In this study, we analyzed how the revenue water ratio(RWR) is affected by changes in conditions of the water supply area, such as the ratio of aging pipes, maintenance conditions, and revenue water. As a result of analyzing the impact of pipe aging and maintenance conditions on the RWR, it was confirmed that the RWR could be decreased if the pipe replacement project to improve the aging pipe ratio was not carried out and proper maintenance costs were not secured. It was also confirmed that an increase in the revenue water could be operated to facilitate the achievement of the project’s target RWR. In contrast, a decrease in the revenue water due to a population reduction could affect the failure of the target RWR. In addition to analyzing the causes of variation in the RWR, the calculation of estimated project costs was considered by using leakage reduction instead of RWR from recent RWR improvement project cost data. From this analysis, it was reviewed whether the project costs planned to achieve the target RWR of the RWR improvement project in A city were appropriate. In conclusion, the RWR could be affected by variations in the ratio of aging pipes, maintenance conditions, and revenue water, and it was reasonable to consider not only the construction input but also the input related to RWR improvement, such as leakage reduction, when calculating the project cost.

Microplastics and nanoplastics (NMPs) are considered one of hazardous contaminants in marine ecosystems due to their toxic effects, such as reproduction disorder and oxidative stress, on marine organisms. Although water temperature is rising due to global climate change, little information on the toxicological interaction between NMPs and temperature is available. Therefore, in this study, we confirmed the toxicity of NMPs (polystyrene [PS] beads; 0.05- and 6-μm) on brackish water fleas (Diaphanosoma celebensis) depending on increased temperature (30°C and 35°C) at individual and molecular levels. In the chronic toxicity test, the group exposed to high temperatures showed an earlier first reproduction time compared to the normal temperatures group, but it was delayed by co-exposure to NMPs at 35°C. Notably, the total reproduction decreased significantly only after 0.05-μm PS beads exposure at 30°C. Interaction analysis showed that first reproduction time, modulation of the antioxidantrelated gene (GSTS1), heat shock gene (Hsp70), and ecdysteroid pathway-related genes (EcR_A, EcR_B, and CYP314A1) were closely related to temperature and PS beads size. These results indicate that microplastics have size-dependent toxicity, and their toxicity can be enhanced at high temperatures. In addition, higher temperatures and PS beads exposure may have negative effects on reproduction. This study suggests that various factors such as water temperature should be considered when evaluating the toxicity of microplastics in marine ecosystems, and provides an understanding of the complex toxic interaction between water temperature and microplastics for marine zooplankton.

Currently, there is no definitive regulation for the appropriate frequency of data sampling in water distribution networks, yet it plays a crucial role in the efficient operation of these systems. This study proposes a new methodology for determining the optimal frequency of data acquisition in water distribution networks. Based on the decomposition of signals using harmonic series, this methodology has been validated using actual data from water distribution networks. By analyzing 12 types of data collected from two points, it was demonstrated that utilizing the factors and cumulative periodograms of harmonic series enables similar accuracy at lower data acquisition frequencies compared to the original signals.

본 연구는 PEBAX/PVDF 복합막을 제조하고 에탄올/물 혼합액에 대한 투과증발 성능을 평가하였다. 또한 PVDF 지지체 표면에 ZIF-8 층을 형성하여 복합막의 투과증발 성능을 향상시키고자 하였고, PEBAX 선택층 두께에 따른 성능 비교 를 통해 최적의 막을 선정하였다. 제작된 복합막을 물과 에탄올이 95/5 중량비로 혼합된 공급액에 대하여 투과증발 실험을 수행하였다. 그 결과 ZIF-8 충이 형성된 PVDF 지지체를 사용한 복합막의 경우 플럭스 1.98 kg/m2h, 분리 계수 3.88로 일반 PVDF 지지체를 사용한 복합막보다 투과량과 선택도가 모두 높은 값을 나타내었다.

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.

플라스틱은 전세계적으로 사용량이 증가함에 따라 해양 환경으로 유입되는 플라스틱 쓰레기의 양도 꾸준히 증가하고 있으며, 미세플라스틱은 해양 생물에 의해 섭취되어 소화관에 축적됨에 따라 성장과 생식에 유해한 영향을 미친다. Cytochrome P450 (CYP)는 환경 오염물질을 대사하 는 해독효소로 알려져 있으나 지각류에서는 그 기능에 대해서는 잘 알려져 있지 않다. 본 연 구에서는 기수산 물벼룩 Diaphanosoma celebensis에서 clan 2, 3, 4에 각각 속하는 CYP 유전자 9종(clan 2: CYP370A4, CYP370C5; clan 3: CYP350A1, CYP350C5, CYP361A1; clan 4: CYP4AN-like, CYP4AP2, CYP4AP3, CYP4C33-like1)의 서열에 대해 진화적으로 보존된 서열의 유사도를 분석 하고 계통분석을 실시하였다. 또한 3종류의 서로 다른 크기의 polystyrene beads (0.05-, 0.5-, 6-μm PS beads; 0.1, 1, and 10 mg/L)에 48시간 노출된 기수산 물벼룩에서 이들 9종의 CYP 유 전자의 발현을 real time reverse transcription polymerase chain reaction (RT-PCR)로 분석하였 다. 결과적으로 기수산 물벼룩 CYP 유전자는 모두 진화적으로 보존된 motif를 가지고 있으며 계통분석 결과 각각 clan 2, 3, 4에 속하는 것으로 확인되었다. 이는 기능적으로 보존되어 있음 을 의미한다. CYP 유전자 중 clan 2에 속하는 CYP370C5와 clan 3에 속하는 CYP360A1, 그리고 clan 4에서는 CYP4C122 유전자의 발현이 0.05-μm PS beads에 노출되었을 때 유의하게 증가 하는 양상을 보였으며, 이는 이들 유전자가 PS 대사에 관여한다는 것을 의미한다. 본 연구는 미세플라스틱이 해양 무척추 동물에 미치는 생물 영향을 분자적 수준에서 이해하는데 도움이 될 것이다.

This study investigated the surface tension and foaming properties of the hot-water extracts of pumpkin leaf and chickpea, as well as the effects of the plant hot-water extracts on white pan bread baking. Propylene glycol alginate (PGA), a synthetic emulsifier widely used in bakery, was used as a control. Pumpkin leaf water extract showed lower surface tension and comparable foaming capacity, compared with chickpea water extract and PGA solution when total solid  0.15% (w/w). Chickpea water extract showed the highest foam stability when total solid  0.15% (w/w). The dough was found to have a weak gel structure, and its viscoelastic properties were not significantly influenced by adding 0.05% or 0.15% (w/w) (based on total solid content) plant water extracts or PGA. The specific volume of the bread increased, and the baking loss was reduced by adding the two plant water extracts of total solid 0.15% (w/w). The hardness and chewiness of the bread crumb were reduced to a level comparable to the crumb containing 0.05% (w/w) PGA. The results showed that the pumpkin leaf water extract could be an effective natural emulsifier with a high phenolic content for bakery products.

This study was conducted to evaluate in vitro antioxidant activity of goat meat hot water extracts and the changes in apoptosis-related protein expression levels in the cancer cells treated with these extracts. Goat meat hot water extracts were prepared using different cuts of goat meat, including foreleg, hindleg, loin, and rib. Among these extracts, the foreleg and hindleg extracts displayed higher (P<0.05) ABTS radical scavenging activity than the other two extracts. Protein expression levels of BAX, p53, and p21 were not different in the cells treated with the extracts from different cuts, regardless of the cell type. Only p53 expression in HT-29 cells was elevated (P<0.05) after loin extract treatment. These results suggest that antioxidant activity and apoptosis-related effects of goat meat hot water extract varied with cut of meat under in vitro conditions. Because all data was obtained from the in vitro experiment, the ability to generalize conclusions is limited. Additional in vivo studies are necessary.

The IUU Fishing Index is composed of 40 indicators. These indicators were grouped by state responsibilities (flag, coastal, port, and general including market) defined in the FAO IPOA-IUU (2001) and then by type into vulnerability, prevalence, and response. A total of 152 coastal nations was surveyed. Korea's total combined IUU Fishing Index was 2.49 in 2019 and 2.91 in 2021, indicating a drop in the ranking to the third worst out of 152 countries followed by China and Russia in 2021. The indicators that increased the IUU fishing risk in 2021 compared to 2019 included seven indicators of prevalence and two indicators of response while those reducing the risk included one prevalence and one response indicator. The IUU Fishing Index revealed that many fisheries observers and monitoring, control and surveillance (MCS) practitioners active in the waters of RFMOs jurisdiction where Korean distant water vessels operate have mentioned concerns about the compliance with RFMO conservation measures or fishing practices. It suggested that strengthening management intervention in the fishing sector is needed. The primary tool for management is the MCS system. Given the logistical difficulty of oversight from land, air and at-sea, there is a need to enhance MCS strategies through logbook data, at-sea observer and electronic monitoring program. It also suggested that MSC fisheries certification and fisheries improvement projects, which are widely used for improving fishing sector performance, could contribute to the eradication of IUU fishing and the promotion of sustainable distant water fisheries.