• Title/Summary/Keyword: weak order

Search Result 1,392, Processing Time 0.024 seconds

Decrease of Aflatoxin M1 Level in Raw Cow’s Milk using the Hazard Analysis and Critical Control Points (HACCP) System (HACCP 제도에 의한 우유의 아플라톡신 M1의 저감화)

  • Kim, Ki-Hwan;Nam, Myoung Soo
    • Journal of Life Science
    • /
    • v.26 no.2
    • /
    • pp.190-197
    • /
    • 2016
  • Aflatoxin M1 can be produced in cow’s milk when cows eat contaminated produce. Milk is a major source of food for infants and for children who have a weak level of immunity, and the detection of Aflatoxin M1 for risk assessment is necessary in order to reduce the amount of it in milk. In this study, the Aflatoxin M1 level was monitored for one year in raw milk samples obtained from Chungnam Province, Korea. The milk samples were divided into three categories: 1. milk samples from a standard general farm, 2. milk samples from a HACCP controlled farm, and 3. milk samples from the supply of Aflatoxin M1 reduced fodder. The average concentrations of Aflatoxin M1 in milk were 0.023±0.005 ug/l for the standard general farm, 0.017±0.004 ug/l for the HACCP controlled farm, and 0.013±0.003 ug/l for the supply of Aflatoxin M1 reduction fodder. Milk collected from the supply of Aflatoxin M1 reduction fodder had the lowest level of Aflatoxin M1. However, when efficiency and economic aspects are considered the most effective way of reducting Aflatoxin M1, could be taking milk from the HACCP controlled farm and implementing good feed management. Institutional support from the government, careful management of dairy farming, and a strict farm sanitation program are required in order to lower the level of Aflatoxin M1 in milk.

A Study on the living and the experience from Captive's story of war during the Second Manchu's invasion in 1636 (병자호란기 조선 피로인(被虜人)의 호지(胡地)체험과 삶)

  • Nam, Mi-Hye
    • (The)Study of the Eastern Classic
    • /
    • no.32
    • /
    • pp.71-101
    • /
    • 2008
  • This study is intended to review the war and the living of the common people of Choseon dynasty, through the true stories of captives kidnapped in the region of the Qing(胡地) during the Pyeongja horan in the 17th century. The common people, Kim seung kyung and Ahn chu won, who had been kidnapped in their young age, managed to escape from the region of the Qing to Choseon after having experienced a painful living as a captive for 27 years. Kim seung kyung and Ahn chu won had to make a choice to run away from the Qing in order to bring their war distorted life back to its original state. Kim seung kyung who had successfully escaped, could live without severe difficulties by the aid of his family living at his hometown, but Ahn chu won who had not found his own family or relatives, couldn't have got any helping hand from the people mentally or financially. So, he tried to escape again to Beijing, but discovered and captured so that a diplomatic problem was caused between the Choseon and the Qing Dynasty. Through the true story of Kim seung kyung and Ahn chu won, we can see the lives of Choseon common people who were trying to overcome the difficulties with their own iron will without being undaunted by hardships. Even though the captives had terrible experiences hating to remember, their experiences gave a chance to the Choseon people opening their eyes to the foreign cultures and the new world. At that time, the Choseon government was too weak to estimate how many captives were or what the captive's real fact was. Meanwhile the Choseon government managed to do the least duty in order to protect its people, by breaking the provisions of repatriation that the fled captives should be returned back to the Qing Dynasty. Through reviewing the captive's true story of the Choseon common people, we can ruminate the Choseon society in the 17th century which failed to establish an independent national history, and the issue of the Korean War captives in the modern history forgotten under the shade of the dustbin of history.

Issues Involving the Relationship between Religion and the Anti-Japanese Independence Movement: A Case Study of Mugeukdo (종교와 항일독립운동, 그리고 쟁점 - 무극도 사례를 중심으로 -)

  • Ko, Byoung-chul
    • Journal of the Daesoon Academy of Sciences
    • /
    • v.35
    • /
    • pp.39-71
    • /
    • 2020
  • Ever since gaining liberation in 1945, Korean society has constantly recalled memories of Japan's invasion and Korea's anti-Japanese movements for an independent state (AMIS). In the process, a small number of new religious groups were also identified as main subjects within AMIS. However, the logic necessary to connect these religious groups with AMIS was still weak. In order to solve this situation academically, the purpose of this article is to illuminate the activities of Mugeukdo (無極道) and Jo Jeongsan (趙鼎山) through the lens of AMIS and to reflect on the issues that will arise when linking the religion with AMIS. Regarding this purpose, this article analyzed the internal and external data collected by Daesoon Jinrihoe (大巡眞理會) about Jo Jeongsan and Mugeukdo's activities linked to AMIS. Later, this paper presents several tasks for future research on this subject matter. Specifically, according to Chapter II, the AMIS of Jo Jeongsan and Mugeukdo were generally centered on resistance at the family level, Jo Jeongsan's order to participate in the March 1st Movement, and Mugeukdo's industrial activities. In Chapter III, I reviewed the contents of Chapter II using Daesoon Jinrihoe's external materials. According to the results of the review, future research is required to discover and cross-check materials related to the AMIS of Jo Jeongsan and Mugeukdo believers. Likewise, further research is needed to highlight the theory of the enthronement of emperor (天子登極說) and the Great Opening of the later world (後天開闢) in terms of AMIS. These efforts can make contributions that increase the credibility of Daesoon Jinrihoe's internal data on the AMIS of Jo Jeongsan and Mugeukdo and expand the periphery of AMIS as it relates to certain religious groups. Subsequently, in Chapter IV, I present three items for reflecting upon the connection between certain religious groups and AMIS. The first is that criteria for establishing the category of AMIS is necessary to determine whether religious activities can be included. Second, reductionist approaches make it difficult to explain the reasons why some of the people who participated in AMIS did so while forming 'new religious movements,' and why these groups have maintained their religious identity even after liberation was achieved in 1945. Third, it is necessary to distinguish between the primary and the secondary dimensions to elaborate on the connection between these religions and AMIS. This means that researchers should be expected to look at whether the activities in question are based on a religious worldview and whether the goal of the activities is the realization of AMIS or the implementation of some aspect of that religious worldview. In the future, considering the mechanisms that make AMIS memorable in Korea, religious groups and religious studies should take greater interest in discovering and accumulating data that facilitates research on these topics. At the same time, effort should be made to find the basis for AMIS within religious worldviews. It can also be made possible through specific interest in further elaboration on the various AMIS-related activities of Jo Jeongsan and Mugeukdo.

Analysis of the First Time User Experience of the online memorial platform and suggestion of service developments (온라인 장례 플랫폼의 초기 사용자 경험 분석및서비스 개발 제안)

  • Jueun Lee;Jindo Hwang
    • Journal of Service Research and Studies
    • /
    • v.14 no.1
    • /
    • pp.44-62
    • /
    • 2024
  • The development of online funeral services and social issues of eco-friendly funeral culture have raised awareness of the new need for online funeral culture. There have been several attempts to revitalize online funeral services in domestic institutions and companies, but the effect is weak. The purpose of this study is to propose a design that can improve the accessibility and usability of online memorial services by analyzing the usability problem factors through a First Time User Experience analysis of the online memorial platform. Therefore, in this study, in order to identify the problem factors of the online memorial platform, a literature review on the UX, OOBE, and FTUE theories was conducted. The subject of the study was the app 'Memorial'. Before analyzing the First-Time User-Experience, IA was compared and analyzed with other similar services to understand the characteristics of the UX service of the app 'Memorial', which is the subject of the study. In addition, tasks corresponding to the Unpack-Setup/Configure-First Use stage were performed on 10 subjects who had no experience using the online memorial platform. The experimental process was expressed as the UX Curve to identify factors that caused negative experiences. As a result, the major problem factors included unnecessary UI elements, the need for sensitive personal information at the membership stage, and lack of immersion in the service. The improvements included strengthening community functions to facilitate the sharing of emotions and promote smooth communication between users. We proposed UI/UX service developments that enhanced the app by incorporating these insights. In order to verify the effectiveness, serviceability, and value of the developed prototype, an interview with a expert was conducted. The interviewes consisted of three service design experts. This study was conducted to contribute to the quality improvement and activation of the recently emerging online funeral services. The study is significant as it aims to understand the current status of these services and identify the factors necessary to improve service accessibility and usability. Subsequent studies require in-depth user verification of how much the proposed improvement plan affects the actual user experience.

Cooperative Sales Promotion in Manufacturer-Retailer Channel under Unplanned Buying Potential (비계획구매를 고려한 제조업체와 유통업체의 판매촉진 비용 분담)

  • Kim, Hyun Sik
    • Journal of Distribution Research
    • /
    • v.17 no.4
    • /
    • pp.29-53
    • /
    • 2012
  • As so many marketers get to use diverse sales promotion methods, manufacturer and retailer in a channel often use them too. In this context, diverse issues on sales promotion management arise. One of them is the issue of unplanned buying. Consumers' unplanned buying is clearly better off for the retailer but not for manufacturer. This asymmetric influence of unplanned buying should be dealt with prudently because of its possibility of provocation of channel conflict. However, there have been scarce studies on the sales promotion management strategy considering the unplanned buying and its asymmetric effect on retailer and manufacturer. In this paper, we try to find a better way for a manufacturer in a channel to promote performance through the retailer's sales promotion efforts when there is potential of unplanned buying effect. We investigate via game-theoretic modeling what is the optimal cost sharing level between the manufacturer and retailer when there is unplanned buying effect. We investigated following issues about the topic as follows: (1) What structure of cost sharing mechanism should the manufacturer and retailer in a channel choose when unplanned buying effect is strong (or weak)? (2) How much payoff could the manufacturer and retailer in a channel get when unplanned buying effect is strong (or weak)? We focus on the impact of unplanned buying effect on the optimal cost sharing mechanism for sales promotions between a manufacturer and a retailer in a same channel. So we consider two players in the game, a manufacturer and a retailer who are interacting in a same distribution channel. The model is of complete information game type. In the model, the manufacturer is the Stackelberg leader and the retailer is the follower. Variables in the model are as following table. Manufacturer's objective function in the basic game is as follows: ${\Pi}={\Pi}_1+{\Pi}_2$, where, ${\Pi}_1=w_1(1+L-p_1)-{\psi}^2$, ${\Pi}_2=w_2(1-{\epsilon}L-p_2)$. And retailer's is as follows: ${\pi}={\pi}_1+{\pi}_2$, where, ${\pi}_1=(p_1-w_1)(1+L-p_1)-L(L-{\psi})+p_u(b+L-p_u)$, ${\pi}_2=(p_2-w_2)(1-{\epsilon}L-p_2)$. The model is of four stages in two periods. Stages of the game are as follows. (Stage 1) Manufacturer sets wholesale price of the first period($w_1$) and cost sharing level of channel sales promotion(${\Psi}$). (Stage 2) Retailer sets retail price of the focal brand($p_1$), the unplanned buying item($p_u$), and sales promotion level(L). (Stage 3) Manufacturer sets wholesale price of the second period($w_2$). (Stage 4) Retailer sets retail price of the second period($p_2$). Since the model is a kind of dynamic games, we try to find a subgame perfect equilibrium to derive some theoretical and managerial implications. In order to obtain the subgame perfect equilibrium, we use the backward induction method. In using backward induction approach, we solve the problems backward from stage 4 to stage 1. By completely knowing follower's optimal reaction to the leader's potential actions, we can fold the game tree backward. Equilibrium of each variable in the basic game is as following table. We conducted more analysis of additional game about diverse cost level of manufacturer. Manufacturer's objective function in the additional game is same with that of the basic game as follows: ${\Pi}={\Pi}_1+{\Pi}_2$, where, ${\Pi}_1=w_1(1+L-p_1)-{\psi}^2$, ${\Pi}_2=w_2(1-{\epsilon}L-p_2)$. But retailer's objective function is different from that of the basic game as follows: ${\pi}={\pi}_1+{\pi}_2$, where, ${\pi}_1=(p_1-w_1)(1+L-p_1)-L(L-{\psi})+(p_u-c)(b+L-p_u)$, ${\pi}_2=(p_2-w_2)(1-{\epsilon}L-p_2)$. Equilibrium of each variable in this additional game is as following table. Major findings of the current study are as follows: (1) As the unplanned buying effect gets stronger, manufacturer and retailer had better increase the cost for sales promotion. (2) As the unplanned buying effect gets stronger, manufacturer had better decrease the cost sharing portion of total cost for sales promotion. (3) Manufacturer's profit is increasing function of the unplanned buying effect. (4) All results of (1),(2),(3) are alleviated by the increase of retailer's procurement cost to acquire unplanned buying items. The authors discuss the implications of those results for the marketers in manufacturers or retailers. The current study firstly suggests some managerial implications for the manufacturer how to share the sales promotion cost with the retailer in a channel to the high or low level of the consumers' unplanned buying potential.

  • PDF

The Reserch on Actual Condition of Crime of Arson Which Occurs in Korea and Its Countermeasures (방화범죄의 실태와 그 대책 - 관심도와 동기의 다양화에 대한 대응 -)

  • Choi, Jong-Tae
    • Korean Security Journal
    • /
    • no.1
    • /
    • pp.371-408
    • /
    • 1997
  • This article is the reserch on actual condition of crime of arson which occurs in Korea and its countermeasures. The the presented problem in this article are that (1) we have generally very low rate concern about the crime of arson contrary to realistic problems of rapid increase of crime of arson (2) as such criminal motives became so diverse as to the economic or criminal purpose unlike characteristic and mental deficiency of old days, and to countermeasure these problems effectively it presentation the necessity of systemantic research. Based on analysis of reality of arson, the tendency of this arson in Korea in the ratio of increase is said to be higher than those in violence crime or general fire rate. and further its rate is far more greater than those of the U.S.A. and Japan. Arson is considered to be a method of using fire as crime and in case of presently residence to be the abject, it is a public offense crime which aqccompany fatality in human life. This is the well It now fact to all of us. And further in order to presentation to the crime of arson, strictness of criminal law (criminal law No, 164 and 169, and fire protection law No. 110 and 111) and classification of arsonist as felony are institutionary reinforced to punish with certainty of possibility, Therefore, as tendency of arson has been increased compared to other nations, it is necessary to supplement strategical policy to bring out overall concerns of the seriousness of risk and damage of arson, which have been resulted from the lack of understanding. In characteristics analysis of crime of arson, (1) It is now reveald that, in the past such crime rate appeared far more within the boundary of town or city areas in the past, presently increased rate of arsons in rural areas are far more than in the town or small city areas, thereby showing characteristics of crime of arson extending nation wide. (2) general timetable of arson shows that night more than day time rate, and reveald that is trait behavior in secrecy.(3) arsonists are usually arrested at site or by victim or report of third person(82,9%).Investigation activities or self surrenders rate only 11.2%. The time span of arrest is normally the same day of arson and at times it takes more than one year to arrest. This reveals its necessity to prepare for long period of time for arrest, (4) age rate of arson is in their thirties mostly as compared to homicide, robbery and adultery, and considerable numbers of arsons are in old age of over fifties. It reveals age rate is increased (5) Over half of the arsonists are below the junior high school (6) the rate of convicts by thier records is based on first offenders primarily and secondly more than 4 time convicts. This apparently shows necessity of effective correctional education policy for their social assimilation together with re-investigation of human education at the primary and secondary education system in thier life. The examples of motivation for arosnits, such as personal animosity, fury, monetary swindle, luscious purpose and other aims of destroying of proof, and other social resistance, violence including ways of threatening, beside the motives of individual defects, are diverse and arsonic suicide and specifically suicidal accompany together keenly manifested. When we take this fact with the criminal theory, it really reveals arsons of crime are increasing and its casualities are serious and a point as a way of suicide is the anomie theory of Durkheim and comensurate with the theory of that of Merton, Specifically in the arson of industrial complex, it is revealed that one with revolutionary motive or revolting motive would do the arsonic act. For the policy of prevention of arsons, professional research work in organizational cooperation for preventive activities is conducted in municipal or city wise functions in the name of Parson Taskforces and beside a variety of research institutes in federal government have been operating effectively to countermeasure in many fields of research. Franch and Sweden beside the U.S. set up a overall operation of fire prevention research funtions and have obtained very successful result. Japan also put their research likewise for countermeasure. In this research as a way of preventive fire policy, first, it is necessary to accomodate the legal preventitive activities for fire prevention in judicial side and as an administrative side, (1) precise statistic management of crime of arson (2) establishment of professional research functions or a corporate (3) improvement of system for cooperative structural team for investigation of fires and menpower organization of professional members. Secondly, social mentality in individual prospect, recognition of fires by arson and youth education of such effect, educational program for development and practical promotion. Thirdly, in view of environmental side, the ways of actual performance by programming with the establishment of cooperative advancement in local social function elements with administrative office, habitants, school facilities and newspapers measures (2) establishment of personal protection where weak menpowers are displayed in special fire prevention measures. These measures are presented for prevention of crime of arson. The control of crime and prevention shall be prepared as a means of self defence by the principle of self responsibility Specifically arsonists usually aims at the comparatively weak control of fire prevention is prevalent and it is therefore necessary to prepare individual facilities with their spontaneous management of fire prevention instead of public municipal funtures of local geverment. As Clifford L. Karchmer asserted instead of concerns about who would commit arson, what portion of area would be the target of the arson. It is effective to minister spontaveously the fire prevention measure in his facility with the consideration of characteristics of arson. On the other hand, it is necessary for the concerned personnel of local goverment and groups to distribute to the local society in timely manner for new information about the fire prevention, thus contribute to effective result of fire prevention result. In consideration of these factors, it is inevitable to never let coincide with the phemonemon of arsons in similar or mimic features as recognized that these could prevail just an epedemic as a strong imitational attitude. In processing of policy to encounter these problems, it is necessary to place priority of city policy to enhancement of overall concerns toward the definitive essense of crime of arson.

  • PDF

Studies on the replacement of raw materials for caramel coloring. - The effects of syrups and catalysts on the properties of Caramel coloring - (Caramel 색소(色素)의 원료대체(原料代替)에 관(關)한 연구(硏究) - 당액(糖液) 및 촉매(觸媒)의 종류(種類)가 Caramel의 성상(性狀)에 미치는 영향(影響) -)

  • Kim, S.Y.;Chang, K.S.
    • Korean Journal of Agricultural Science
    • /
    • v.3 no.1
    • /
    • pp.105-119
    • /
    • 1976
  • Sucrose, glucose, starches hydrolyzates and raw starchy materials hydrolyzates were caramelized using various catalysis and the caramel products were analysed, in order to carry out the basic research for the replacement of caramel coloring. The results obtained were summarized as follows. 1. The caramel which was manufactured by sucrose syrup being pH 3.5 adjusted by sulfuric acid showed strong color intensity and hue as well as good stability in the solutions of table salt, tannin and alcohol. 2. The product caramelized from sucrose syrup being pH 9.5 adjusted by sodium carbonate showed very strong color intensity and black color component, and was quite stable in alcohol solution but not in table salt and tannin solutions. 3. The caramel products made from sucrose syrup using ammonium salts of strong acid like $NH_4Cl$ and $(NH_4)_2SO_4$ as catalyst showed strong color intensity and black color component but hazy apparence in solution of table salt, tannin and alcohol. 4. The product caramelized from glucose syrup being pH 9.5 adjusted by sodium carbonate indicated strong color intensity but weak red color component and was transparent in solution of table salt and alcohol but hazy in tannin solution. 5. In glucose caramel using $NH_4Cl$, $(NH_4)_2SO_4$, $(NH_4)_2CO_3$ and $(NH_4)_2SO_3$ as catalyst, $NH_4Cl$ plot was very weak in color intensity and insufficient in red color component but stable in solution of table salt, tannin and alcohol. In the case of $(NH_4)_2CO_3$, $(NH_4)_2SO_4$ and $(NH_4)_2SO_3$ plots, all products were strong in color intensity but little insufficient in red color component. On the stability in solutions, $(NH_4)_2SO_3$ plot was stable in two solutions expect tannin solution, $(NH_4)_2CO_3$ plot was only stable in alcohol solution and $(NH_4)_2SO_3$ plot was only stable in table salt solution. 6. When the acid hydrolyzed starch syrups without neutralization were caramelized using $(NH_4)_2SO_4$ as catalyst, the potato starch hydrolyzate caramel showed higher in color intensity being similar to its of glucose caramel than sweet potato starch hydrolyzate caramel and corn starch hydrolyzate caramel. 7. Dried sweet potato powder, dried acorns powders, the acorns (from Q. serrata THUNB and Q. acutissima CARR.) powders extracted with water for 7 days and with 50% alcohol solution for 24 hrs were hydrolyzed by sulfuric acid in autoclave at $3.5kg/cm^2$ as pressure for 60 mins, and were caramelized using $(NH_4)_2SO_4$ as catalyst. It was supposed that all of those products were poor quality on color and stability in solutions at the viewpoint of food coloring matter.

  • PDF

Clinical Impact of Bronchial Reactivity and Its Relationship with Changes of Pulmonary Function After Asthmatic Attack Induced by Methacholine (기관지 반응성의 임상적 의의 및 메타콜린으로 유도된 천식 발작시 폐기능 변화와의 관계)

  • Ryu, Yon-Ju;Choi, Young-Ju;Kwak, Jae-Jin;Lee, Ji-A;Nam, Seung-Hyun;Park, Chang-Han;Chaon, Saon-Hee
    • Tuberculosis and Respiratory Diseases
    • /
    • v.52 no.1
    • /
    • pp.24-36
    • /
    • 2002
  • Background: Bronchial reactivity is known to be a component of airway hyperresponsiveness, a cardinal feature of asthma, with bronchial sensitivity, and is increments in response to induced doses of bronchoconstrictors as manifested by the steepest slope of the dose-response curve. However, there is some controversy regarding methods of measuring bronchial reactivity and clinical impact of such measurements. The purpose of this study was to evaluate the clinical significance and assess the clinical use by analyzing the relationship of the bronchial sensitivity, the clinical severity and the changes in pulmonary function with bronchial reactivity. Method: A total of 116 subjects underwent a methacholine bronchial provocation test. They were divided into 3 groups : mild intermittent, mild persistent, moderate and cough asthma. Severe patients were excluded. Methacholine PC20 was determined from the log dose-response curve and PC40 was determined by one more dose inhalation after PC20. The steepest slope of log dose-response curve, connecting PC20 with PC40, was used to calculate the bronchial reactivity. Body plethysmography and a single breath for the DLCO were done in 43 subjects before and after methacholine test. Results: The average bronchial reactivity was 38.0 in the mild intermittent group, 49.8 in the mild persistent group, 61.0 in the moderate group, and 41.1 in the cough asthma group. There was a weak negative correlation between PC20 and bronchial reactivity. A heightened bronchial reactivity tends to produce an increased clinical severity in patients with a similar bronchial sensitivity and basal spirometric pulmonary function. There were significant correlations between the bronchial reactivity and the initial pulmonary function before the methacholine test in the order of sGaw, Raw, $FEV_1$/FVC, MMFR. There were no correlations between the bronchial sensitivity and the % change in the pulmonary function parameters after the methacholine test. However, there were significant correlations between the bronchial reactivity and the PEF, $FEV_1$, DLCO. Conclusion: There was weak significant negative correlation between the bronchial reactivity and the bronchial sensitivity, and the bronchial reactivity closely reflected the severity of the asthma. Accordingly, measuring both the bronchial sensitivity and the bronchial reactivity can be of assistance in assessing of the ongoing disease severity and in monitoring the effect of therapy.

Rates and Factors of Path Widening in Seongpanak Hiking Trail of Mount Halla, Jeju Island (한라산 성판악 등산로 노폭의 확대 속도와 요인)

  • Kim, Tae-Ho
    • Journal of the Korean Geographical Society
    • /
    • v.43 no.3
    • /
    • pp.296-311
    • /
    • 2008
  • In order to examine the rates and factors of path widening in Mount Halla, the retreat of path sidewalls was monitored at 32 sites of Seongpanak Hiking Trail located between 875 m and 1,400 m in elevation. The mean rate of sidewall retreat for the period 2002-2008 is 50.6 mm, equivalent to 10.0 mm/yr. The retreat rate of frozen period is 19.3 mm/yr, while the rate of unfrozen period is 4.3 mm/yr. The latter is divided into the rainy and dry periods that exhibit the retreat rates of 5.9 mm/yr and 2.9 mm/yr, respectively. The retreat rate of sidewalls is also varied with seasons; winter shows the maximum rate of 42.2 mm/yr, while summer exhibits the minimum rate of 1.3 mm/yr. Spring and fall show the intermediate rates of 13.9 mm/yr and 6.4 mm/yr, respectively. Soil hardness and elevation are not closely related to the retreat rate of sidewalls, even though the retreat rate is larger at the north-faced sidewalls than the south-faced sidewalls during the frozen period. Pipkrake is likely to be the most important factor contributing to the path widening in that the retreat of winter months accounts for 76.7% of the total retreat. The hiking trail is placed under the climatic conditions which develop pipkrake in 85 days annually. In addition, it is usual to observe the path sidewall covered with pipkrake in the freezing month of December and the thawing months of March and April. On the other hand, deflation and rainsplash erosion are not important due to the weak wind speed and the forested trail. Rainwash is also insignificant in that the path has been almost paved to mitigate trampling effects. Although biological activity is not dominant, hikers cause a large retreat of sidewalls in the thawing months since they would walk on the sidewalls to avoid snow-melting pools on the path.

Applicability of Partial Post-Tension Method for Deflection Control of Reinforced Concrete Slabs (RC슬래브의 처짐제어를 위한 상향긴장식 부분PT공법의 적용)

  • Lee, Deuck-Hang;Kim, Kang-Su;Kim, Sang-Sik;Kim, Yong-Nam;Lim, Joo-Hyuk
    • Journal of the Korea Concrete Institute
    • /
    • v.21 no.3
    • /
    • pp.347-358
    • /
    • 2009
  • Recently, it is getting into a good situation for the flat-plate slab system to be applied. The flat-plate slab without beam, however, is often too weak to control deflection properly compared to other typical slab-beam structures, for which the post-tension method is generally regarded as one of best solutions. The post-tension (PT) method can effectively control deflection without increase of slab thickness. Despite this good advantage, however, the application of PT method has been very limited due to cost increase, technical problems, and lack of experiences. Therefore, in order to reduce difficulties on applying full PT method under the current domestic circumstances and to enhance constructability of PT system, this research proposed the partial PT method with top jacking anchorage applied in a part of span as need. For the top jacking anchorage system, the efficiency of deflection control shall be considered in detail because it can vary widely depending on the location of anchorage that can be placed anywhere as need, and tensile stresses induced at back of the anchorage zone also shall be examined. Therefore, in this study, analysis were performed on the efficiency of deflection control depending on the location of anchorage and on tensile stresses or forces using finite element method and strut and tie model in the proposed top jacking anchorage system. The proposed jacking system were also applied to the floor slabs at a construction site to investigate its applicability and the analysis results of slab behavior were compared to the measured values obtained from the PT slab constructed by the partial PT method. The result of this study indicates that the partial PT method can be very efficiently applied with little cost increase to control deflection and tensile stresses in the region as a need basis where problem exists.