• Korean Journal of Agricultural Science
• /
• v.47 no.4
• /
• pp.1135-1145
• /
• 2020

The purpose of this study was to compare and analyze the emissions of SOx and NH3 for a 78 kW class agricultural tractor during agricultural operations. A real-time monitoring system was constructed for measuring the load data. The field test was conducted during plow and rotary tillage. The working conditions were selected with the transmission gears in M3 Low and M2 High for the plow tillage and L3 High and L3 Low for the rotary tillage. The engine torque and fuel consumption were measured using controller area network (CAN) communication, and the emissions of SOx and NH3 were calculated based on the fuel consumption. As a result of the field tests, the engine torque was higher for the plow tillage than for the rotary tillage. As the gear stage was increased, the engine torque became higher. The emissions of SOx and NH3 were higher for the plow tillage than for the rotary tillage because the fuel consumption increased. Moreover, the emissions of SOx and NH3 tended to be more distributed for the rotary tillage than for the plow tillage. To develop an emission factor for agricultural machinery, it is important to measure reliable emission data during agricultural operations. In a future study, we will collect various emission data using a portable emission measurement system during agricultural operations.

• Journal of Korean Academic Society of Home Health Care Nursing
• /
• v.30 no.1
• /
• pp.5-14
• /
• 2023

Purpose: This study aims to identify the degree of anxiety and depression related to infection control and job stress in clinical nurses during the COVID-19 pandemic. Furthermore, it seeks to identify the effects of depression. Finally, it intends to develop intervention measures to prevent depression in clinical nurses during epidemics of new infectious diseases and prepare basic data for developing educational programs. Methods: Data were collected using a self-report questionnaire survey administered to 208 nurses. The data were analyzed using the IBM SPSS (Version 26.0) statistics program. Results: The correlation analysis between participant depression, anxiety, and infection control job stress found that depression had a positive correlation with anxiety (r=.63, p<.001) and infection control work stress (r=.26, p<.001). Anxiety (β=0.60, p<.001) was found to significantly affect participant depression with an explanatory power of 40.2%, confirming that higher anxiety levels induce increased depression. Conclusion: Based on the above results, anxiety is confirmed to be a factor that affects depression. Accordingly, education is required to strengthen individuals' physical and mental capabilities and promote a safe working environment, including providing sufficient personal protective devices and other appropriate gear to defend clinical nurses against outbreaks of emerging infectious diseases at medical institutions and through healthcare policies. Other considerations should include sufficient rest hours and paying additional benefits for nurses caring for patients with severe confirmed COVID-19.

• Weed & Turfgrass Science
• /
• v.5 no.4
• /
• pp.203-212
• /
• 2016

In order to investigate actual pesticide usage, this survey was carried out with farmers growing four crop groups, leaf vegetables, fruit vegetables, fruits, and rice from 2012 to 2015. Five hundred sixty farmers were selected in main crop production areas and were asked about their pesticide uses during the growing season. Investigations on pesticide damages to crop in recent 5 years showed that fruit vegetables had the highest proportion of damage at 14%, followed by rice at 11%, orchards at 11%, and leaf vegetables at 8%. Compared to the results of a pilot study which took place from 2009 to 2011, fruit vegetable damage increased by 4% while damage to rice and orchards decreased by 7-9%. This means continuous education on mixed spraying, usage methods, and precaution is required. In the survey on the safety guidelines for pesticide use, 6 items were well observed (89.0-95.0%), but one item for use of protective gear had the lowest observance (81.7%). A measure for protective gear for poisoning prevention is required. The survey of pesticide usage per area ($kg\;a.i.\;ha^{-1}$) showed that 1.65, 4.93, 10.98, and $3.16kg\;a.i.\;ha^{-1}$ of pesticides were applied to leaf vegetables (6 species), fruit vegetables (6 species), fruits (6 species), and rice, respectively, which decreased from the usage reported in the pilot study. This change was likely caused by more effective pesticides and fewer pest outbreaks; therefore, shipments of pesticides have been decreasing. In the case of paddy rice herbicides, 43 products, including butachlor, were used for $1.3kg\;ha^{-1}$. Herbicides represent 44% of pesticides used in paddy rice.

• Atmosphere
• /
• v.15 no.4
• /
• pp.191-202
• /
• 2005

This study was conducted to estimate how vertically high and horizontally long a sea breeze occurred around Gangneung of the Korean peninsula would be reached to an inland. Geographically, gangneung is located on the center of the east coast shaping an arc, and a coastal line around gangneung has a form extending northwestward and southeastward, respectively. Therefore, an inflow of the northerly has similar effects of the sea breeze since a deep valley of Daegwallyeong, which is one of main ridges of the Taebaek mountains, not only reaches northeastward up to this region but also plays the part of the steering gear changing a wind direction from northerly to easterly, this is, the wind from sea. First of all, the study had defined the sea breeze as a wind blown from NNE to ESE, clockwise. And then, we analyzed characteristics of the sea breeze occurred around gangneung in view of the maximum wind speed and the wind direction for October 1st, 2003 through September 30th, 2004, the upper air database for May through June of 2004, and the wind vector database of AWS (Automatic Weather System). All meteorological information is collected at the weather station of gangneung and by the AWS which is being scattered around this region. Finally, the study figures out that how horizontally long a sea breeze would be reached depends on a level of the easterly inflow. At the first step of the inflow of the sea breeze, the wind from NNW blows into this region by keeping up the speed $3m{\cdot}s^{-1}$, and effects of the northerly are dominated with time and the wind at the inland blows out southwestward cause of the surface friction at the next step. On the other hand, there is no change of wind direction in the inflow at Daegwallyeong because a surface friction of there is smaller than around gangneung, relatively. In other word, the easterly blows toward Daegwallyeong. However, the wind speed is not higher than that of the coast around gangneung.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.42 no.3
• /
• pp.134-147
• /
• 2006

A model experiment using circulation water channel was carried out to investigate the dynamic characteristics of bottom trawl net which can be used in sea mount of North Pacific. Hydrodynamic resistance and shape variation according to the flow velocity and angle of hand rope transformation for net were measured, and experimental value was analyzed as the value of full-scale bottom trawl net. The results summarized are as follows; At the $30^{\circ}$ of angle of hand rope to net, hydrodynamic resistance varied from 0.5kgf to 2.68kgf as the flow velocity increased between 0.31m/s and 0.92m/s, and formula of hydrodynamic resistance for the model net was $F_m=3.04\;{\cdot}\;{\upsilon}^{1.53}$. At the fixed angle of hand rope, Net height was low and Net width was high according to the increase of flow velocity, and in addition, vertical opening was low and Net width was high by the increase of angle of hand rope at the fixed flow velocity. At the $30^{\circ}$ of angle of hand rope to net, net opening area was $0.214m^2$ as flow velocity was 0.61m/s, and formula of net opening area for the model net was $S_m=-0.22{\upsilon}+0.35$. At the $30^{\circ}$ of angle of hand rope to net, catch efficiency seemed to be highest as $0.319m^3/s$ of filtering volume at the 0.76m/s(51kt's) of flow velocity. Shape variation of net showed the gradual laminar transform for the variation of flow velocity but there needed some improvements due to the occurrence of shortening at the ahead of wing net.

• Journal of Distribution Science
• /
• v.6 no.2
• /
• pp.5-19
• /
• 2008

This study aims to provide the present general state of basic data about refrigeration and freezing warehouses scold storages because basic data about refrigeration and freezing warehouses are insufficient and imperfect at the moment. Research contents include the present general state of cold storages such as sales amount, capital(money invested), storage possession state by type, keeping area, cold storage facility capacity, and facility state such as existence of rack, building structure and floor height, and possessed facility state. According to research results, it was found that 86.7% of refrigeration and freezing warehouses are located in the capital region and Busan region in terms of regional distribution, and the average keeping area was found to be bigger in these two regions than that of other regions. In addition, the research shows that more than 80% of companies possess bonded warehouses and there was no big difference in the size and capacity of refrigeration and freezing warehouses. Regarding building structure, most of them were found to be reinforced concrete. However, only 25% of companies installed racks, but there was no statistical significance between existence of rack and the amount of capital and sales. Possessed facilities were found in the order of freight elevator, information system and dock. When it comes to cargo gear, companies were found to possess 9.1 units of forklift and 2.2 units of reach stacker in average. This research is expected to lay a basis for investigating, predicting and developing the local cold storage industry, and more detailed studies will be needed in the future.

• Korean Journal of Applied Biomechanics
• /
• v.26 no.1
• /
• pp.11-20
• /
• 2016

Objective: This study aimed to compare biomechanical data between elite and beginner cyclists during cycle pedaling by performing a comparative analysis and to provide quantitative data for both pedaling performance enhancement and injury prevention. Methods: The subjects of this study included 5 elite cyclists (age: $18{\pm}0years$, body mass: $64.8{\pm}9.52kg$, height: $173.0{\pm}4.80cm$) and 5 amateur cyclists (age: $20{\pm}0years$, mass: $66.6{\pm}2.36kg$, height: $175.6{\pm}1.95cm$). The subjects pedaled on a stationary bicycle mounted on rollers of the same gear (front: 50 T and rear: 17 T = 2.94) and cadence of 90. The saddle height was adjusted to fit the body of each subject, and all the subjects wore shoes with cleats. In order to obtain kinematic data, 4 cameras (GR-HD1KR, JVC, Japan) were installed and set at 60 frames/sec. An electromyography (EMG) system (Telemyo 2400T, Noraxon, USA) was used to measure muscle activation. Eight sets of data from both the left and right lower extremities were obtained from 4 muscles (vastus medialis oblique [VMO], vastus lateralis oblique [VLO], and semitendinosus [Semitend], and lateral gastrocnemius [Gastro]) bilaterally by using a sampling frequency of 1,500 Hz. Five sets of events ($0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, and $360^{\circ}$) and 4 phases (P1, P2, P3, and P4) were set up for the data analysis. Imaging data were analyzed for kinematic factors by using the Kwon3D XP computer software (Visol, Korea). MyoResearch XP Master Edition (Noraxon) was used for filtering and processing EMG signals. Results: The angular velocity at $360^{\circ}$ from the feet was higher in the amateur cyclists, but accelerations at $90^{\circ}$ and $180^{\circ}$ were higher in the elite cyclists. The amateur cyclists had greater joint angles at $270^{\circ}$ from the ankle and wider knee joint distance at $0^{\circ}$, $180^{\circ}$, and $360^{\circ}$ than the elite cyclists. The EMG measurements showed significant differences between P2 and P4 from both the right VLO and Semitend. Conclusion: This study showed that lower body movements appeared to be different according to the level of cycle pedaling experience. This finding may be used to improve pedaling performance and prevent injuries among cyclists.

• Journal of Korean society of Dental Hygiene
• /
• v.11 no.4
• /
• pp.557-569
• /
• 2011

Objectives : Based on the system and control activity for the monitoring system made of components for infection control at dental hospitals and infection rate reporting, and the role of trained infection control staff, this study tried to understand approaches to the effective infection control program by surveying infection control at dental hospitals in Korea. Methods : The survey was conducted from December 14,2010 to January 31,2011 for 121 dental hospitals in Korea. For statistical analysis, PASW Statistic 18 was used. Results : And following conclusions were reached. 1. As for the infection control system at dental hospitals, 54.7% has an infection control committee, 58.7% infection control staff, 78.5% infection control rules, and 39.7% annual infection control plan and record. 2. As for surveillance indexes to report infection rates, 50.4% has the reporting system for staff's exposure to infectious disease and needle pricking. The average number of exposures to infectious disease was $0.28{\pm}2.23$ and that of needle pricking was $1.83{\pm}5.39$. 3. As for infection control indexes, it was reviewed whether infection control rules were implemented according to operation agents, general hospitals were more active in staff infection control, and hospitals annexed to a dental university or special legal entity were more active in microorganism control. As for use of personal protection gear, there was no significant difference among operation agents. More than 71% of operators and their assistants said they did not replace their masks between patients. 4. As for personnel indexes for effective infection control staff, most hospitals designated dental hygienists, which was followed by dental doctors (or doctors). Where their workload was reviewed, the ratio of other work such as treatment was relatively higher than that of infection control (n=71). Conclusions : These results show dental hospitals in Korea have a certain level of infection control system. As infection indexes are managed mainly for staff members, patient monitoring is needed, and trained and effective infection control staff should be designated. This study reviewed surveillance, infection control and personnel indexes. And further studies are needed in the future.